Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in hci_conn_drop

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1375 [inline]
BUG: KASAN: slab-use-after-free in hci_conn_drop+0x34/0x2bc include/net/bluetooth/hci_core.h:1523
Write of size 4 at addr ffff0000c892c010 by task syz-executor.0/6752

CPU: 0 PID: 6752 Comm: syz-executor.0 Not tainted 6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x174/0x514 mm/kasan/report.c:475
 kasan_report+0xd8/0x138 mm/kasan/report.c:588
 kasan_check_range+0x254/0x294 mm/kasan/generic.c:187
 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_dec_and_test include/linux/atomic/atomic-instrumented.h:1375 [inline]
 hci_conn_drop+0x34/0x2bc include/net/bluetooth/hci_core.h:1523
 __sco_sock_close+0x3a8/0x7b0 net/bluetooth/sco.c:443
 sco_sock_close net/bluetooth/sco.c:468 [inline]
 sco_sock_release+0xb4/0x2c0 net/bluetooth/sco.c:1245
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

Allocated by task 6753:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 kmalloc_trace+0x70/0x88 mm/slab_common.c:1122
 kmalloc include/linux/slab.h:599 [inline]
 kzalloc include/linux/slab.h:720 [inline]
 hci_conn_add+0xcc/0x1210 net/bluetooth/hci_conn.c:957
 hci_connect_sco+0x94/0x2bc net/bluetooth/hci_conn.c:1701
 sco_connect net/bluetooth/sco.c:265 [inline]
 sco_sock_connect+0x270/0x8bc net/bluetooth/sco.c:590
 __sys_connect_file net/socket.c:2050 [inline]
 __sys_connect+0x268/0x290 net/socket.c:2067
 __do_sys_connect net/socket.c:2077 [inline]
 __se_sys_connect net/socket.c:2074 [inline]
 __arm64_sys_connect+0x7c/0x94 net/socket.c:2074
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

Freed by task 5665:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:522
 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1800 [inline]
 slab_free_freelist_hook mm/slub.c:1826 [inline]
 slab_free mm/slub.c:3809 [inline]
 __kmem_cache_free+0x2ac/0x480 mm/slub.c:3822
 kfree+0xb8/0x19c mm/slab_common.c:1075
 bt_link_release+0x20/0x30 net/bluetooth/hci_sysfs.c:16
 device_release+0x8c/0x1ac
 kobject_cleanup lib/kobject.c:682 [inline]
 kobject_release lib/kobject.c:716 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x1c4/0x3c4 lib/kobject.c:733
 put_device+0x28/0x40 drivers/base/core.c:3732
 hci_conn_put include/net/bluetooth/hci_core.h:1506 [inline]
 hci_conn_cleanup net/bluetooth/hci_conn.c:178 [inline]
 hci_conn_del+0x78c/0xabc net/bluetooth/hci_conn.c:1156
 hci_conn_failed+0x204/0x2c0 net/bluetooth/hci_conn.c:1252
 hci_abort_conn_sync+0x688/0xe38 net/bluetooth/hci_sync.c:5428
 abort_conn_sync+0x5c/0x8c net/bluetooth/hci_conn.c:2910
 hci_cmd_sync_work+0x1cc/0x34c net/bluetooth/hci_sync.c:306
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857

The buggy address belongs to the object at ffff0000c892c000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 16 bytes inside of
 freed 4096-byte region [ffff0000c892c000, ffff0000c892d000)

The buggy address belongs to the physical page:
page:00000000c7691a02 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x108928
head:00000000c7691a02 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x5ffc00000000840(slab|head|node=0|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 05ffc00000000840 ffff0000c0002140 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000c892bf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000c892bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff0000c892c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff0000c892c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000c892c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
ODEBUG: assert_init not available (active state 0) object: 000000000c51268a object type: timer_list hint: hci_conn_timeout+0x0/0x1e8 net/bluetooth/hci_conn.c:928
WARNING: CPU: 0 PID: 6752 at lib/debugobjects.c:517 debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
Modules linked in:
CPU: 0 PID: 6752 Comm: syz-executor.0 Tainted: G    B              6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
lr : debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
sp : ffff800096f67790
x29: ffff800096f67790 x28: dfff800000000000 x27: ffff700012decf00
x26: dfff800000000000 x25: dfff800000000000 x24: ffff0000c892c390
x23: ffff80008ad651a0 x22: ffff800089881d98 x21: ffff80008a89c360
x20: 0000000000000000 x19: ffff80008ad64cc0 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80008a668980 x15: 0000000000000001
x14: 1ffff00012dece0c x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000000 x9 : c73071275ea21a00
x8 : c73071275ea21a00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800096f67078 x4 : ffff80008e4210a0 x3 : ffff8000803639bc
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
 debug_object_assert_init+0x318/0x3c8 lib/debugobjects.c:941
 debug_timer_assert_init kernel/time/timer.c:792 [inline]
 debug_assert_init kernel/time/timer.c:837 [inline]
 __timer_delete+0xac/0x2f8 kernel/time/timer.c:1321
 timer_delete+0x24/0x34 kernel/time/timer.c:1361
 del_timer include/linux/timer.h:213 [inline]
 try_to_grab_pending+0x8c/0x618 kernel/workqueue.c:1564
 __cancel_work+0xb0/0x2a8 kernel/workqueue.c:3582
 cancel_delayed_work+0x24/0x38 kernel/workqueue.c:3620
 hci_conn_drop+0x150/0x2bc include/net/bluetooth/hci_core.h:1548
 __sco_sock_close+0x3a8/0x7b0 net/bluetooth/sco.c:443
 sco_sock_close net/bluetooth/sco.c:468 [inline]
 sco_sock_release+0xb4/0x2c0 net/bluetooth/sco.c:1245
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
irq event stamp: 15717
hardirqs last  enabled at (15717): [<ffff80008a719110>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (15717): [<ffff80008a719110>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (15716): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (15458): [<ffff8000888c272c>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (15458): [<ffff8000888c272c>] lock_sock_nested+0xcc/0x11c net/core/sock.c:3512
softirqs last disabled at (15456): [<ffff8000888c26d4>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (15456): [<ffff8000888c26d4>] lock_sock_nested+0x74/0x11c net/core/sock.c:3508
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
WARNING: CPU: 0 PID: 6752 at kernel/workqueue.c:1939 __queue_delayed_work kernel/workqueue.c:1939 [inline]
WARNING: CPU: 0 PID: 6752 at kernel/workqueue.c:1939 queue_delayed_work_on+0x214/0x2e4 kernel/workqueue.c:1986
Modules linked in:
CPU: 0 PID: 6752 Comm: syz-executor.0 Tainted: G    B   W          6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 804000c5 (Nzcv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : __queue_delayed_work kernel/workqueue.c:1939 [inline]
pc : queue_delayed_work_on+0x214/0x2e4 kernel/workqueue.c:1986
lr : __queue_delayed_work kernel/workqueue.c:1939 [inline]
lr : queue_delayed_work_on+0x214/0x2e4 kernel/workqueue.c:1986
sp : ffff800096f67af0
x29: ffff800096f67af0 x28: 1fffe0001a828d80 x27: dfff800000000000
x26: 0000000000000000 x25: ffff0000c892c3a8 x24: ffff0000cb635400
x23: 0000000000000000 x22: ffff0000c892c348 x21: 0000000000000008
x20: 0000000000000000 x19: 0000000000000000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80008a71b2bc x15: ffff600019125869
x14: 1fffe00019125869 x13: 00000000000000fb x12: ffffffffffffffff
x11: 0000000000000001 x10: 0000000000000000 x9 : 0000000000000000
x8 : ffff0000d5f21bc0 x7 : 0000000000000000 x6 : 0000000000000000
x5 : 0000000000000000 x4 : 0000000000000000 x3 : ffff800080221e68
x2 : 0000000000000000 x1 : 0000000000000008 x0 : 0000000000000000
Call trace:
 __queue_delayed_work kernel/workqueue.c:1939 [inline]
 queue_delayed_work_on+0x214/0x2e4 kernel/workqueue.c:1986
 queue_delayed_work include/linux/workqueue.h:569 [inline]
 hci_conn_drop+0x198/0x2bc include/net/bluetooth/hci_core.h:1549
 __sco_sock_close+0x3a8/0x7b0 net/bluetooth/sco.c:443
 sco_sock_close net/bluetooth/sco.c:468 [inline]
 sco_sock_release+0xb4/0x2c0 net/bluetooth/sco.c:1245
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
irq event stamp: 15717
hardirqs last  enabled at (15717): [<ffff80008a719110>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (15717): [<ffff80008a719110>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (15716): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (15458): [<ffff8000888c272c>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (15458): [<ffff8000888c272c>] lock_sock_nested+0xcc/0x11c net/core/sock.c:3512
softirqs last disabled at (15456): [<ffff8000888c26d4>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (15456): [<ffff8000888c26d4>] lock_sock_nested+0x74/0x11c net/core/sock.c:3508
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
ODEBUG: activate not available (active state 0) object: 000000002ed6b31e object type: work_struct hint: hci_conn_timeout+0x0/0x1e8 net/bluetooth/hci_conn.c:928
WARNING: CPU: 0 PID: 6752 at lib/debugobjects.c:517 debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
Modules linked in:
CPU: 0 PID: 6752 Comm: syz-executor.0 Tainted: G    B   W          6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
pstate: 604000c5 (nZCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
lr : debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
sp : ffff800096f67870
x29: ffff800096f67870 x28: dfff800000000000 x27: ffff700012decf1c
x26: ffff0000e2130b78 x25: dfff800000000000 x24: ffff0000c892c348
x23: ffff80008ad651a0 x22: ffff800089881d98 x21: ffff80008a8710a0
x20: 0000000000000000 x19: ffff80008ad64c40 x18: 0000000000000000
x17: 0000000000000000 x16: ffff80008a71b2bc x15: 0000000000000001
x14: 1fffe0003682f032 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000002 x10: 0000000000000000 x9 : c73071275ea21a00
x8 : c73071275ea21a00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800096f67158 x4 : ffff80008e4210a0 x3 : ffff8000805a359c
x2 : 0000000000000001 x1 : 0000000000000002 x0 : 0000000000000000
Call trace:
 debug_print_object+0x168/0x1e0 lib/debugobjects.c:514
 debug_object_activate+0x600/0x7e0 lib/debugobjects.c:760
 debug_work_activate kernel/workqueue.c:572 [inline]
 insert_work+0x4c/0x2d4 kernel/workqueue.c:1644
 __queue_work+0xcf4/0x1338 kernel/workqueue.c:1799
 __queue_delayed_work kernel/workqueue.c:1950 [inline]
 queue_delayed_work_on+0x1f4/0x2e4 kernel/workqueue.c:1986
 queue_delayed_work include/linux/workqueue.h:569 [inline]
 hci_conn_drop+0x198/0x2bc include/net/bluetooth/hci_core.h:1549
 __sco_sock_close+0x3a8/0x7b0 net/bluetooth/sco.c:443
 sco_sock_close net/bluetooth/sco.c:468 [inline]
 sco_sock_release+0xb4/0x2c0 net/bluetooth/sco.c:1245
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595
irq event stamp: 15717
hardirqs last  enabled at (15717): [<ffff80008a719110>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (15717): [<ffff80008a719110>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (15716): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (15458): [<ffff8000888c272c>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (15458): [<ffff8000888c272c>] lock_sock_nested+0xcc/0x11c net/core/sock.c:3512
softirqs last disabled at (15456): [<ffff8000888c26d4>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (15456): [<ffff8000888c26d4>] lock_sock_nested+0x74/0x11c net/core/sock.c:3508
---[ end trace 0000000000000000 ]---


Tested on:

commit:         8de1e7af Merge branch 'for-next/core' into for-kernelci
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=13ba3458e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=150ac400e80000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[xingwei lee]

Hello

I reproduced both two bugs with relatively stable poc, hope it helps.
In my prograss, I meet three bugs titles are respectively

KASAN: slab-out-of-bounds Write in sco_sock_timeout
https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
KASAN: slab-use-after-free Write in sco_conn_del
https://syzkaller.appspot.com/bug?extid=6b9277cad941daf126a2
KASAN: wild-memory-access Read in lock_sock_nested may be new.

My reproducer can crash in the latest net tree HEAD:
1ae4cd3cbdd08287c56c4cc816ebf05eb6681a0f and also the latest upstream
mainline.
However, when I try to execute their reproducer, the crash seems the
same, this makes me very likely that they are maybe the same bug.

TITLE: KASAN: slab-use-after-free Write in sco_sock_timeout
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write
home/dubbo/net/./include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed
home/dubbo/net/./include/linux/atomic/atomic-instrumented.h:252
[inline]
BUG: KASAN: slab-use-after-free in __refcount_add
home/dubbo/net/./include/linux/refcount.h:193 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc
home/dubbo/net/./include/linux/refcount.h:250 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc
home/dubbo/net/./include/linux/refcount.h:267 [inline]
BUG: KASAN: slab-use-after-free in sock_hold
home/dubbo/net/./include/net/sock.h:777 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x68/0x2b0
home/dubbo/net/net/bluetooth/sco.c:88
Write of size 4 at addr ffff888156922080 by task kworker/1:0/8390
CPU: 1 PID: 8390 Comm: kworker/1:0 Not tainted 6.7.0-rc4-00141-g1ae4cd3cbdd0 #3
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
1.16.2-debian-1.16.2-1 04/01/4
Workqueue: events sco_sock_timeout
Call Trace:
 <TASK>
 __dump_stack home/dubbo/net/lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd9/0x1b0 home/dubbo/net/lib/dump_stack.c:106
 print_address_description home/dubbo/net/mm/kasan/report.c:364 [inline]
 print_report+0xc4/0x620 home/dubbo/net/mm/kasan/report.c:475
 kasan_report+0xda/0x110 home/dubbo/net/mm/kasan/report.c:588
 check_region_inline home/dubbo/net/mm/kasan/generic.c:181 [inline]
 kasan_check_range+0xef/0x190 home/dubbo/net/mm/kasan/generic.c:187
 instrument_atomic_read_write
home/dubbo/net/./include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed
home/dubbo/net/./include/linux/atomic/atomic-instrumented.h:252
[inline]
 __refcount_add home/dubbo/net/./include/linux/refcount.h:193 [inline]
 __refcount_inc home/dubbo/net/./include/linux/refcount.h:250 [inline]
 refcount_inc home/dubbo/net/./include/linux/refcount.h:267 [inline]
 sock_hold home/dubbo/net/./include/net/sock.h:777 [inline]
 sco_sock_timeout+0x68/0x2b0 home/dubbo/net/net/bluetooth/sco.c:88
 process_one_work+0x830/0x1550 home/dubbo/net/kernel/workqueue.c:2627
 process_scheduled_works home/dubbo/net/kernel/workqueue.c:2700 [inline]
 worker_thread+0x8b9/0x1290 home/dubbo/net/kernel/workqueue.c:2781
 kthread+0x33c/0x440 home/dubbo/net/kernel/kthread.c:388
 ret_from_fork+0x45/0x80 home/dubbo/net/arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x11/0x20 home/dubbo/net/arch/x86/entry/entry_64.S:242
 </TASK>
Allocated by task 8208:
 kasan_save_stack+0x33/0x50 home/dubbo/net/mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 home/dubbo/net/mm/kasan/common.c:52
 ____kasan_kmalloc home/dubbo/net/mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xa2/0xb0 home/dubbo/net/mm/kasan/common.c:383
 kasan_kmalloc home/dubbo/net/./include/linux/kasan.h:198 [inline]
 __do_kmalloc_node home/dubbo/net/mm/slab_common.c:1007 [inline]
 __kmalloc+0x60/0x100 home/dubbo/net/mm/slab_common.c:1020
 kmalloc home/dubbo/net/./include/linux/slab.h:604 [inline]
 sk_prot_alloc+0x1a4/0x2a0 home/dubbo/net/net/core/sock.c:2075
 sk_alloc+0x36/0xb80 home/dubbo/net/net/core/sock.c:2128
 bt_sock_alloc+0x3b/0x3e0 home/dubbo/net/net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc home/dubbo/net/net/bluetooth/sco.c:495 [inline]
 sco_sock_create+0xe3/0x3b0 home/dubbo/net/net/bluetooth/sco.c:526
 bt_sock_create+0x180/0x340 home/dubbo/net/net/bluetooth/af_bluetooth.c:132
 __sock_create+0x328/0x800 home/dubbo/net/net/socket.c:1569
 sock_create home/dubbo/net/net/socket.c:1620 [inline]
 __sys_socket_create home/dubbo/net/net/socket.c:1657 [inline]
 __sys_socket+0x14c/0x260 home/dubbo/net/net/socket.c:1704
 __do_sys_socket home/dubbo/net/net/socket.c:1718 [inline]
 __se_sys_socket home/dubbo/net/net/socket.c:1716 [inline]
 __x64_sys_socket+0x72/0xb0 home/dubbo/net/net/socket.c:1716
 do_syscall_x64 home/dubbo/net/arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x3f/0x110 home/dubbo/net/arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
Freed by task 8209:
 kasan_save_stack+0x33/0x50 home/dubbo/net/mm/kasan/common.c:45
 kasan_set_track+0x25/0x30 home/dubbo/net/mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 home/dubbo/net/mm/kasan/generic.c:522
 ____kasan_slab_free home/dubbo/net/mm/kasan/common.c:236 [inline]
 ____kasan_slab_free+0x15b/0x1b0 home/dubbo/net/mm/kasan/common.c:200
 kasan_slab_free home/dubbo/net/./include/linux/kasan.h:164 [inline]
 slab_free_hook home/dubbo/net/mm/slub.c:1800 [inline]
 slab_free_freelist_hook+0x114/0x1e0 home/dubbo/net/mm/slub.c:1826
 slab_free home/dubbo/net/mm/slub.c:3809 [inline]
 __kmem_cache_free+0xc0/0x180 home/dubbo/net/mm/slub.c:3822
 sk_prot_free home/dubbo/net/net/core/sock.c:2111 [inline]
 __sk_destruct+0x602/0x770 home/dubbo/net/net/core/sock.c:2203
 sk_destruct+0xc2/0xf0 home/dubbo/net/net/core/sock.c:2218
 __sk_free+0xf4/0x3e0 home/dubbo/net/net/core/sock.c:2229
 sk_free+0x7c/0xa0 home/dubbo/net/net/core/sock.c:2240
 sock_put home/dubbo/net/./include/net/sock.h:1990 [inline]
 sco_sock_kill home/dubbo/net/net/bluetooth/sco.c:426 [inline]
 sco_sock_kill+0x19d/0x1c0 home/dubbo/net/net/bluetooth/sco.c:416
 sco_sock_release+0x154/0x2c0 home/dubbo/net/net/bluetooth/sco.c:1256
 __sock_release+0xae/0x260 home/dubbo/net/net/socket.c:659
 sock_close+0x1c/0x20 home/dubbo/net/net/socket.c:1419
 __fput+0x270/0xbb0 home/dubbo/net/fs/file_table.c:394
 task_work_run+0x14d/0x240 home/dubbo/net/kernel/task_work.c:180
 get_signal+0x1077/0x26e0 home/dubbo/net/kernel/signal.c:2680
 arch_do_signal_or_restart+0x90/0x7f0
home/dubbo/net/arch/x86/kernel/signal.c:309
 exit_to_user_mode_loop home/dubbo/net/kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 home/dubbo/net/kernel/entry/common.c:204
 __syscall_exit_to_user_mode_work
home/dubbo/net/kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x60 home/dubbo/net/kernel/entry/common.c:296
 do_syscall_64+0x4b/0x110 home/dubbo/net/arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
Last potentially related work creation:
 kasan_save_stack+0x33/0x50 home/dubbo/net/mm/kasan/common.c:45
 __kasan_record_aux_stack+0xbc/0xd0 home/dubbo/net/mm/kasan/generic.c:492
 __call_rcu_common.constprop.0+0x9a/0x790 home/dubbo/net/kernel/rcu/tree.c:2681
 netlink_release+0x120d/0x1ff0 home/dubbo/net/net/netlink/af_netlink.c:831
 __sock_release+0xae/0x260 home/dubbo/net/net/socket.c:659
 sock_close+0x1c/0x20 home/dubbo/net/net/socket.c:1419
 __fput+0x270/0xbb0 home/dubbo/net/fs/file_table.c:394
 __fput_sync+0x47/0x50 home/dubbo/net/fs/file_table.c:475
 __do_sys_close home/dubbo/net/fs/open.c:1590 [inline]
 __se_sys_close home/dubbo/net/fs/open.c:1575 [inline]
 __x64_sys_close+0x87/0xf0 home/dubbo/net/fs/open.c:1575
 do_syscall_x64 home/dubbo/net/arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x3f/0x110 home/dubbo/net/arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
The buggy address belongs to the object at ffff888156922000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff888156922000, ffff888156922800)
The buggy address belongs to the physical page:
page:ffffea00055a4800 refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x15690
head:ffffea00055a4800 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000840(slab|head|node=1|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 057ff00000000840 ffff888012c43240 ffffea00053b0e10 ffffea000502e810
raw: 0000000000000000 0000000000050005 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask
0xd2040(__GFP_IO|__GFP_N3
 set_page_owner home/dubbo/net/./include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x2cf/0x340 home/dubbo/net/mm/page_alloc.c:1537
 prep_new_page home/dubbo/net/mm/page_alloc.c:1544 [inline]
 get_page_from_freelist+0xa28/0x36c0 home/dubbo/net/mm/page_alloc.c:3312
 __alloc_pages+0x1d0/0x4a0 home/dubbo/net/mm/page_alloc.c:4568
 alloc_pages_mpol+0x258/0x5f0 home/dubbo/net/mm/mempolicy.c:2133
 alloc_slab_page home/dubbo/net/mm/slub.c:1870 [inline]
 allocate_slab+0x251/0x380 home/dubbo/net/mm/slub.c:2017
 new_slab home/dubbo/net/mm/slub.c:2070 [inline]
 ___slab_alloc+0x8c7/0x1580 home/dubbo/net/mm/slub.c:3223
 __slab_alloc.constprop.0+0x56/0xa0 home/dubbo/net/mm/slub.c:3322
 __slab_alloc_node home/dubbo/net/mm/slub.c:3375 [inline]
 slab_alloc_node home/dubbo/net/mm/slub.c:3468 [inline]
 __kmem_cache_alloc_node+0x131/0x310 home/dubbo/net/mm/slub.c:3517
 __do_kmalloc_node home/dubbo/net/mm/slab_common.c:1006 [inline]
 __kmalloc+0x4f/0x100 home/dubbo/net/mm/slab_common.c:1020
 kmalloc home/dubbo/net/./include/linux/slab.h:604 [inline]
 kzalloc home/dubbo/net/./include/linux/slab.h:721 [inline]
 tomoyo_init_log+0x1276/0x1f60 home/dubbo/net/security/tomoyo/audit.c:275
 tomoyo_supervisor+0x30c/0x1170 home/dubbo/net/security/tomoyo/common.c:2089
 tomoyo_audit_env_log home/dubbo/net/security/tomoyo/environ.c:36 [inline]
 tomoyo_env_perm+0x18f/0x200 home/dubbo/net/security/tomoyo/environ.c:63
 tomoyo_environ home/dubbo/net/security/tomoyo/domain.c:672 [inline]
 tomoyo_find_next_domain+0xed8/0x2020
home/dubbo/net/security/tomoyo/domain.c:878
 tomoyo_bprm_check_security home/dubbo/net/security/tomoyo/tomoyo.c:101 [inline]
 tomoyo_bprm_check_security+0x12b/0x1d0
home/dubbo/net/security/tomoyo/tomoyo.c:91
 security_bprm_check+0x6a/0xe0 home/dubbo/net/security/security.c:1103
 search_binary_handler home/dubbo/net/fs/exec.c:1725 [inline]
 exec_binprm home/dubbo/net/fs/exec.c:1779 [inline]
 bprm_execve home/dubbo/net/fs/exec.c:1854 [inline]
 bprm_execve+0x73a/0x1a90 home/dubbo/net/fs/exec.c:1810
page last free stack trace:
 reset_page_owner home/dubbo/net/./include/linux/page_owner.h:24 [inline]
 free_pages_prepare home/dubbo/net/mm/page_alloc.c:1137 [inline]
 free_unref_page_prepare+0x4e5/0xa20 home/dubbo/net/mm/page_alloc.c:2347
 free_unref_page+0x33/0x3b0 home/dubbo/net/mm/page_alloc.c:2487
 qlink_free home/dubbo/net/mm/kasan/quarantine.c:168 [inline]
 qlist_free_all+0x6a/0x170 home/dubbo/net/mm/kasan/quarantine.c:187
 kasan_quarantine_reduce+0x18e/0x1d0 home/dubbo/net/mm/kasan/quarantine.c:294
 __kasan_slab_alloc+0x65/0x90 home/dubbo/net/mm/kasan/common.c:305
 kasan_slab_alloc home/dubbo/net/./include/linux/kasan.h:188 [inline]
 slab_post_alloc_hook home/dubbo/net/mm/slab.h:763 [inline]
 slab_alloc_node home/dubbo/net/mm/slub.c:3478 [inline]
 slab_alloc home/dubbo/net/mm/slub.c:3486 [inline]
 __kmem_cache_alloc_lru home/dubbo/net/mm/slub.c:3493 [inline]
 kmem_cache_alloc+0x163/0x390 home/dubbo/net/mm/slub.c:3502
 kmem_cache_zalloc home/dubbo/net/./include/linux/slab.h:711 [inline]
 alloc_empty_file+0x73/0x1d0 home/dubbo/net/fs/file_table.c:216
 path_openat+0xdd/0x2c40 home/dubbo/net/fs/namei.c:3765
 do_filp_open+0x1de/0x430 home/dubbo/net/fs/namei.c:3809
 do_sys_openat2+0x176/0x1e0 home/dubbo/net/fs/open.c:1440
 do_sys_open home/dubbo/net/fs/open.c:1455 [inline]
 __do_sys_openat home/dubbo/net/fs/open.c:1471 [inline]
 __se_sys_openat home/dubbo/net/fs/open.c:1466 [inline]
 __x64_sys_openat+0x175/0x210 home/dubbo/net/fs/open.c:1466
 do_syscall_x64 home/dubbo/net/arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x3f/0x110 home/dubbo/net/arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
Memory state around the buggy address:
 ffff888156921f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888156922000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888156922080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff888156922100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888156922180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


and my reproducer is at the same kernel commit at the lastest net tree
kernel commit: 1ae4cd3cbdd08287c56c4cc816ebf05eb6681a0f
kernel config: https://syzkaller.appspot.com/text?tag=KernelConfig&x=b50bd31249191be8

KASAN: slab-out-of-bounds Write in sco_sock_timeout:
https://gist.github.com/xrivendell7/0dbaa3529a9845b008c31e0bc6c29236
KASAN: slab-use-after-free Write in sco_conn_del:
https://gist.github.com/xrivendell7/b813252b1c8f3f35aaee1af60b698d0a
KASAN: wild-memory-access Read in lock_sock_nested:
https://gist.github.com/xrivendell7/f2a0fba9a55413c64c6153d03cd3df58

all the gist contains the report, repro.c and repro.txt
BTW, I also run another crash maybe related to this one, Titled:

KASAN: use-after-free Write in sco_sock_timeout
KASAN: slab-out-of-bounds Write in sco_sock_timeout
KASAN: slab-use-after-free Write in __sco_sock_close
WARNING: refcount bug in sco_sock_timeout
INFO: trying to register non-static key in sco_sock_timeout

However, for now, i can not reproduce those bugs with stable reproducer.
I hope is helps.

Best Regards
xingwei Lee

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

syzbot has bisected this issue to:

commit 9a8ec9e8ebb5a7c0cfbce2d6b4a6b67b2b78e8f3
Author: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Date:   Thu Mar 30 21:15:50 2023 +0000

    Bluetooth: SCO: Fix possible circular locking dependency on sco_connect_cfm

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=179a65d2e80000
start commit:   bee0e7762ad2 Merge tag 'for-linus-iommufd' of git://git.ke..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=145a65d2e80000
console output: https://syzkaller.appspot.com/x/log.txt?x=105a65d2e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b50bd31249191be8
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1504504ae80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14685f54e80000

Reported-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com
Fixes: 9a8ec9e8ebb5 ("Bluetooth: SCO: Fix possible circular locking dependency on sco_connect_cfm")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
KASAN: slab-use-after-free Write in sco_sock_timeout

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:777 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
Write of size 4 at addr ffff0000db795080 by task kworker/0:3/6101

CPU: 0 PID: 6101 Comm: kworker/0:3 Not tainted 6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events sco_sock_timeout
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x174/0x514 mm/kasan/report.c:475
 kasan_report+0xd8/0x138 mm/kasan/report.c:588
 kasan_check_range+0x254/0x294 mm/kasan/generic.c:187
 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:193 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:777 [inline]
 sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857

Allocated by task 6617:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1026 [inline]
 __kmalloc+0xcc/0x1b8 mm/slab_common.c:1039
 kmalloc include/linux/slab.h:603 [inline]
 sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:2090
 sk_alloc+0x44/0x3f4 net/core/sock.c:2143
 bt_sock_alloc+0x4c/0x32c net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:496 [inline]
 sco_sock_create+0xbc/0x31c net/bluetooth/sco.c:527
 bt_sock_create+0x14c/0x248 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x43c/0x884 net/socket.c:1569
 sock_create net/socket.c:1620 [inline]
 __sys_socket_create net/socket.c:1657 [inline]
 __sys_socket+0x134/0x340 net/socket.c:1708
 __do_sys_socket net/socket.c:1722 [inline]
 __se_sys_socket net/socket.c:1720 [inline]
 __arm64_sys_socket+0x7c/0x94 net/socket.c:1720
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

Freed by task 6617:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:522
 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1800 [inline]
 slab_free_freelist_hook mm/slub.c:1826 [inline]
 slab_free mm/slub.c:3809 [inline]
 __kmem_cache_free+0x2ac/0x480 mm/slub.c:3822
 kfree+0xb8/0x19c mm/slab_common.c:1075
 sk_prot_free net/core/sock.c:2126 [inline]
 __sk_destruct+0x4c0/0x770 net/core/sock.c:2218
 sk_destruct net/core/sock.c:2233 [inline]
 __sk_free+0x37c/0x4e8 net/core/sock.c:2244
 sk_free+0x60/0xc8 net/core/sock.c:2255
 sock_put include/net/sock.h:1989 [inline]
 sco_sock_kill+0xfc/0x1b4 net/bluetooth/sco.c:427
 sco_sock_release+0x1fc/0x2c0 net/bluetooth/sco.c:1257
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 ____fput+0x20/0x30 fs/file_table.c:412
 task_work_run+0x230/0x2e0 kernel/task_work.c:180
 get_signal+0x13f4/0x15ec kernel/signal.c:2668
 do_signal arch/arm64/kernel/signal.c:1249 [inline]
 do_notify_resume+0x3bc/0x393c arch/arm64/kernel/signal.c:1302
 exit_to_user_mode_prepare arch/arm64/kernel/entry-common.c:137 [inline]
 exit_to_user_mode arch/arm64/kernel/entry-common.c:144 [inline]
 el0_svc+0x9c/0x158 arch/arm64/kernel/entry-common.c:679
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

The buggy address belongs to the object at ffff0000db795000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff0000db795000, ffff0000db795800)

The buggy address belongs to the physical page:
page:0000000058a39b68 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000db797000 pfn:0x11b790
head:0000000058a39b68 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x5ffc00000000840(slab|head|node=0|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 05ffc00000000840 ffff0000c0002000 ffff0000c0000948 fffffc0003359410
raw: ffff0000db797000 0000000000080006 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000db794f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000db795000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000db795080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff0000db795100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000db795180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 6101 at lib/refcount.c:25 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 6101 Comm: kworker/0:3 Tainted: G    B              6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
lr : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
sp : ffff800096c47af0
x29: ffff800096c47af0 x28: 1fffe0001abfc00a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d5fe0050 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000002
x20: ffff0000db795080 x19: ffff8000910a2000 x18: ffff800096c47800
x17: 0000000000000000 x16: ffff80008a6688c0 x15: 0000000000000001
x14: 1ffff00012d88e78 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000000 x9 : 345179c02a25c000
x8 : 345179c02a25c000 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800096c473d8 x4 : ffff80008e4210a0 x3 : ffff8000803639bc
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:777 [inline]
 sco_sock_timeout+0x19c/0x25c net/bluetooth/sco.c:88
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 5571
hardirqs last  enabled at (5571): [<ffff80008a719050>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (5571): [<ffff80008a719050>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (5570): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (5414): [<ffff800085cd6e40>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (5414): [<ffff800085cd6e40>] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
softirqs last  enabled at (5414): [<ffff800085cd6e40>] nsim_dev_trap_report_work+0x620/0x924 drivers/net/netdevsim/dev.c:850
softirqs last disabled at (5412): [<ffff800085cd6dbc>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (5412): [<ffff800085cd6dbc>] nsim_dev_trap_report drivers/net/netdevsim/dev.c:816 [inline]
softirqs last disabled at (5412): [<ffff800085cd6dbc>] nsim_dev_trap_report_work+0x59c/0x924 drivers/net/netdevsim/dev.c:850
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 6101 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 6101 Comm: kworker/0:3 Tainted: G    B   W          6.6.0-rc7-syzkaller-00089-g8de1e7afcc1c-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/09/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
lr : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
sp : ffff800096c47af0
x29: ffff800096c47af0 x28: 1fffe0001abfc00a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d5fe0050 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000003
x20: ffff0000db795080 x19: ffff8000910a2000 x18: 1fffe0003682efce
x17: 0000000000000000 x16: ffff80008a71b1fc x15: 0000000000000001
x14: 1ffff00012d88eb0 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 345179c02a25c000
x8 : 345179c02a25c000 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800096c473d8 x4 : ffff80008e4210a0 x3 : ffff800082b180c4
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
 __refcount_sub_and_test include/linux/refcount.h:283 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 sock_put include/net/sock.h:1988 [inline]
 sco_sock_timeout+0x1b0/0x25c net/bluetooth/sco.c:100
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 5571
hardirqs last  enabled at (5571): [<ffff80008a719050>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (5571): [<ffff80008a719050>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (5570): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (5414): [<ffff800085cd6e40>] spin_unlock_bh include/linux/spinlock.h:396 [inline]
softirqs last  enabled at (5414): [<ffff800085cd6e40>] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline]
softirqs last  enabled at (5414): [<ffff800085cd6e40>] nsim_dev_trap_report_work+0x620/0x924 drivers/net/netdevsim/dev.c:850
softirqs last disabled at (5412): [<ffff800085cd6dbc>] spin_lock_bh include/linux/spinlock.h:356 [inline]
softirqs last disabled at (5412): [<ffff800085cd6dbc>] nsim_dev_trap_report drivers/net/netdevsim/dev.c:816 [inline]
softirqs last disabled at (5412): [<ffff800085cd6dbc>] nsim_dev_trap_report_work+0x59c/0x924 drivers/net/netdevsim/dev.c:850
---[ end trace 0000000000000000 ]---


Tested on:

commit:         8de1e7af Merge branch 'for-next/core' into for-kernelci
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14336477680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=139b4e48e80000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com

Tested on:

commit:         8de1e7af Merge branch 'for-next/core' into for-kernelci
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
console output: https://syzkaller.appspot.com/x/log.txt?x=14ace3d4e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=15faf610e80000

Note: testing is done by a robot and is best-effort only.

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot tried to test the proposed patch but the build/boot failed:

net/bluetooth/sco.c:418:26: error: static assertion failed due to requirement '__builtin_types_compatible_p(struct sock, struct sock *) || __builtin_types_compatible_p(struct sock, void)': pointer type mismatch in container_of()


Tested on:

commit:         8de1e7af Merge branch 'for-next/core' into for-kernelci
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
patch:          https://syzkaller.appspot.com/x/patch.diff?x=1417b23f680000

Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot has tested the proposed patch and the reproducer did not trigger any issue:

Reported-and-tested-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com

Tested on:

commit:         7475e51b Merge tag 'net-6.7-rc2' of git://git.kernel.o..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=17b8635b680000
kernel config:  https://syzkaller.appspot.com/x/.config?x=696dc362ad4818c4
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

Note: no patches were applied.
Note: testing is done by a robot and is best-effort only.

[syzbot] [bluetooth?] KASAN: slab-use-after-free Write in sco_sock_timeout

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    8de1e7afcc1c Merge branch 'for-next/core' into for-kernelci
git tree:       git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=1126f190e80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=3e6feaeda5dcbc27
dashboard link: https://syzkaller.appspot.com/bug?extid=4c0d0c4cde787116d465
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=122a2560e80000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=136e08df680000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/0f00907f9764/disk-8de1e7af.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/0502fe78c60d/vmlinux-8de1e7af.xz
kernel image: https://storage.googleapis.com/syzbot-assets/192135168cc0/Image-8de1e7af.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4c0d0c4cde787116d465@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: slab-use-after-free in atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
BUG: KASAN: slab-use-after-free in __refcount_add include/linux/refcount.h:193 [inline]
BUG: KASAN: slab-use-after-free in __refcount_inc include/linux/refcount.h:250 [inline]
BUG: KASAN: slab-use-after-free in refcount_inc include/linux/refcount.h:267 [inline]
BUG: KASAN: slab-use-after-free in sock_hold include/net/sock.h:777 [inline]
BUG: KASAN: slab-use-after-free in sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
Write of size 4 at addr ffff0000dba59080 by task kworker/0:1/10

CPU: 0 PID: 10 Comm: kworker/0:1 Not tainted 6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events sco_sock_timeout
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x174/0x514 mm/kasan/report.c:475
 kasan_report+0xd8/0x138 mm/kasan/report.c:588
 kasan_check_range+0x254/0x294 mm/kasan/generic.c:187
 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline]
 __refcount_add include/linux/refcount.h:193 [inline]
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:777 [inline]
 sco_sock_timeout+0x64/0x25c net/bluetooth/sco.c:88
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857

Allocated by task 6180:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_alloc_info+0x24/0x30 mm/kasan/generic.c:511
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0xac/0xc4 mm/kasan/common.c:383
 kasan_kmalloc include/linux/kasan.h:198 [inline]
 __do_kmalloc_node mm/slab_common.c:1026 [inline]
 __kmalloc+0xcc/0x1b8 mm/slab_common.c:1039
 kmalloc include/linux/slab.h:603 [inline]
 sk_prot_alloc+0xc4/0x1f0 net/core/sock.c:2090
 sk_alloc+0x44/0x3f4 net/core/sock.c:2143
 bt_sock_alloc+0x4c/0x32c net/bluetooth/af_bluetooth.c:148
 sco_sock_alloc net/bluetooth/sco.c:495 [inline]
 sco_sock_create+0xbc/0x31c net/bluetooth/sco.c:526
 bt_sock_create+0x14c/0x248 net/bluetooth/af_bluetooth.c:132
 __sock_create+0x43c/0x884 net/socket.c:1569
 sock_create net/socket.c:1620 [inline]
 __sys_socket_create net/socket.c:1657 [inline]
 __sys_socket+0x134/0x340 net/socket.c:1708
 __do_sys_socket net/socket.c:1722 [inline]
 __se_sys_socket net/socket.c:1720 [inline]
 __arm64_sys_socket+0x7c/0x94 net/socket.c:1720
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

Freed by task 6179:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4c/0x7c mm/kasan/common.c:52
 kasan_save_free_info+0x38/0x5c mm/kasan/generic.c:522
 ____kasan_slab_free+0x144/0x1c0 mm/kasan/common.c:236
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:244
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1800 [inline]
 slab_free_freelist_hook mm/slub.c:1826 [inline]
 slab_free mm/slub.c:3809 [inline]
 __kmem_cache_free+0x2ac/0x480 mm/slub.c:3822
 kfree+0xb8/0x19c mm/slab_common.c:1075
 sk_prot_free net/core/sock.c:2126 [inline]
 __sk_destruct+0x4c0/0x770 net/core/sock.c:2218
 sk_destruct net/core/sock.c:2233 [inline]
 __sk_free+0x37c/0x4e8 net/core/sock.c:2244
 sk_free+0x60/0xc8 net/core/sock.c:2255
 sock_put include/net/sock.h:1989 [inline]
 sco_sock_kill+0xfc/0x1b4 net/bluetooth/sco.c:426
 sco_sock_release+0x1fc/0x2c0 net/bluetooth/sco.c:1256
 __sock_release net/socket.c:659 [inline]
 sock_close+0xa4/0x1e8 net/socket.c:1419
 __fput+0x324/0x7f8 fs/file_table.c:384
 __fput_sync+0x60/0x9c fs/file_table.c:465
 __do_sys_close fs/open.c:1572 [inline]
 __se_sys_close fs/open.c:1557 [inline]
 __arm64_sys_close+0x150/0x1e0 fs/open.c:1557
 __invoke_syscall arch/arm64/kernel/syscall.c:37 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:51
 el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:136
 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:155
 el0_svc+0x54/0x158 arch/arm64/kernel/entry-common.c:678
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:696
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:595

The buggy address belongs to the object at ffff0000dba59000
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 128 bytes inside of
 freed 2048-byte region [ffff0000dba59000, ffff0000dba59800)

The buggy address belongs to the physical page:
page:00000000f24a79df refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11ba58
head:00000000f24a79df order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x5ffc00000000840(slab|head|node=0|zone=2|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 05ffc00000000840 ffff0000c0002000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000dba58f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000dba59000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000dba59080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff0000dba59100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000dba59180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
------------[ cut here ]------------
refcount_t: addition on 0; use-after-free.
WARNING: CPU: 0 PID: 10 at lib/refcount.c:25 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/0:1 Tainted: G    B              6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
lr : refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
sp : ffff800092d57af0
x29: ffff800092d57af0 x28: 1fffe0001a9b5a4a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d4dad250 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000002
x20: ffff0000dba59080 x19: ffff8000910a2000 x18: ffff800092d57800
x17: 0000000000000000 x16: ffff80008a71b23c x15: 0000000000000001
x14: 1ffff000125aaeb0 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000001 x10: 0000000000000000 x9 : c0b0806111008b00
x8 : c0b0806111008b00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800092d573d8 x4 : ffff80008e4210a0 x3 : ffff800082b180c4
x2 : 0000000000000001 x1 : 0000000000000001 x0 : 0000000000000000
Call trace:
 refcount_warn_saturate+0x1a8/0x20c lib/refcount.c:25
 __refcount_inc include/linux/refcount.h:250 [inline]
 refcount_inc include/linux/refcount.h:267 [inline]
 sock_hold include/net/sock.h:777 [inline]
 sco_sock_timeout+0x19c/0x25c net/bluetooth/sco.c:88
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 29659
hardirqs last  enabled at (29659): [<ffff80008a719090>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (29659): [<ffff80008a719090>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (29658): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (19646): [<ffff800080021894>] softirq_handle_end kernel/softirq.c:399 [inline]
softirqs last  enabled at (19646): [<ffff800080021894>] __do_softirq+0xac0/0xd54 kernel/softirq.c:582
softirqs last disabled at (19597): [<ffff80008002aadc>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
---[ end trace 0000000000000000 ]---
------------[ cut here ]------------
refcount_t: underflow; use-after-free.
WARNING: CPU: 0 PID: 10 at lib/refcount.c:28 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
Modules linked in:
CPU: 0 PID: 10 Comm: kworker/0:1 Tainted: G    B   W          6.6.0-rc7-syzkaller-g8de1e7afcc1c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events sco_sock_timeout
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
lr : refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
sp : ffff800092d57af0
x29: ffff800092d57af0 x28: 1fffe0001a9b5a4a x27: dfff800000000000
x26: ffff0000c1084008 x25: ffff0000d4dad250 x24: ffff0001b418b500
x23: dfff800000000000 x22: 0000000000000000 x21: 0000000000000003
x20: ffff0000dba59080 x19: ffff8000910a2000 x18: ffff800092d57800
x17: 0000000000000000 x16: ffff80008a71b23c x15: 0000000000000001
x14: 1fffe0003682f032 x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : c0b0806111008b00
x8 : c0b0806111008b00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff800092d573d8 x4 : ffff80008e4210a0 x3 : ffff8000805a359c
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 refcount_warn_saturate+0x1c8/0x20c lib/refcount.c:28
 __refcount_sub_and_test include/linux/refcount.h:283 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 sock_put include/net/sock.h:1988 [inline]
 sco_sock_timeout+0x1b0/0x25c net/bluetooth/sco.c:100
 process_one_work+0x694/0x1204 kernel/workqueue.c:2630
 process_scheduled_works kernel/workqueue.c:2703 [inline]
 worker_thread+0x938/0xef4 kernel/workqueue.c:2784
 kthread+0x288/0x310 kernel/kthread.c:388
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:857
irq event stamp: 29659
hardirqs last  enabled at (29659): [<ffff80008a719090>] __exit_to_kernel_mode arch/arm64/kernel/entry-common.c:84 [inline]
hardirqs last  enabled at (29659): [<ffff80008a719090>] exit_to_kernel_mode+0xdc/0x10c arch/arm64/kernel/entry-common.c:94
hardirqs last disabled at (29658): [<ffff800080021724>] __do_softirq+0x950/0xd54 kernel/softirq.c:569
softirqs last  enabled at (19646): [<ffff800080021894>] softirq_handle_end kernel/softirq.c:399 [inline]
softirqs last  enabled at (19646): [<ffff800080021894>] __do_softirq+0xac0/0xd54 kernel/softirq.c:582
softirqs last disabled at (19597): [<ffff80008002aadc>] ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:80
---[ end trace 0000000000000000 ]---


---
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