* KASAN: use-after-free Read in service_outstanding_interrupt
@ 2020-08-07 12:19 syzbot
2020-12-18 3:21 ` syzbot
[not found] ` <20201218082113.1238-1-hdanton@sina.com>
0 siblings, 2 replies; 8+ messages in thread
From: syzbot @ 2020-08-07 12:19 UTC (permalink / raw)
To: andreyknvl, gregkh, gustavoars, ingrassia, linux-kernel,
linux-usb, syzkaller-bugs
Hello,
syzbot found the following issue on:
HEAD commit: 7b4ea945 Revert "x86/mm/64: Do not sync vmalloc/ioremap ma..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=108adf32900000
kernel config: https://syzkaller.appspot.com/x/.config?x=72a84c46d0c668c
dashboard link: https://syzkaller.appspot.com/bug?extid=9e04e2df4a32fb661daf
compiler: gcc (GCC) 10.1.0-syz 20200507
Unfortunately, I don't have any reproducer for this issue yet.
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+9e04e2df4a32fb661daf@syzkaller.appspotmail.com
==================================================================
BUG: KASAN: use-after-free in usb_submit_urb+0x10c4/0x13e0 drivers/usb/core/urb.c:368
Read of size 4 at addr ffff8881caa52018 by task syz-executor.3/13922
CPU: 1 PID: 13922 Comm: syz-executor.3 Not tainted 5.8.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xf6/0x16e lib/dump_stack.c:118
print_address_description.constprop.0+0x1a/0x210 mm/kasan/report.c:383
__kasan_report mm/kasan/report.c:513 [inline]
kasan_report.cold+0x37/0x7c mm/kasan/report.c:530
usb_submit_urb+0x10c4/0x13e0 drivers/usb/core/urb.c:368
service_outstanding_interrupt.part.0+0x5f/0xa0 drivers/usb/class/cdc-wdm.c:463
service_outstanding_interrupt drivers/usb/class/cdc-wdm.c:458 [inline]
wdm_read+0x9a0/0xbd0 drivers/usb/class/cdc-wdm.c:576
vfs_read+0x1df/0x520 fs/read_write.c:479
ksys_read+0x12d/0x250 fs/read_write.c:607
do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45ce79
Code: 2d b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 fb b5 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f8d2099fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00000000000252c0 RCX: 000000000045ce79
RDX: 00000000000000f2 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 00007ffd66f595ff R14: 00007f8d209a09c0 R15: 000000000118bf2c
Allocated by task 4524:
save_stack+0x1b/0x40 mm/kasan/common.c:48
set_track mm/kasan/common.c:56 [inline]
__kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
kmalloc include/linux/slab.h:555 [inline]
kzalloc include/linux/slab.h:669 [inline]
usb_alloc_dev+0x51/0xf67 drivers/usb/core/usb.c:582
hub_port_connect drivers/usb/core/hub.c:5114 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5348 [inline]
port_event drivers/usb/core/hub.c:5494 [inline]
hub_event+0x1dff/0x4390 drivers/usb/core/hub.c:5576
process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x392/0x470 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
Freed by task 5477:
save_stack+0x1b/0x40 mm/kasan/common.c:48
set_track mm/kasan/common.c:56 [inline]
kasan_set_free_info mm/kasan/common.c:316 [inline]
__kasan_slab_free+0x116/0x160 mm/kasan/common.c:455
slab_free_hook mm/slub.c:1474 [inline]
slab_free_freelist_hook+0x53/0x140 mm/slub.c:1507
slab_free mm/slub.c:3072 [inline]
kfree+0xbc/0x2c0 mm/slub.c:4052
device_release+0x71/0x200 drivers/base/core.c:1800
kobject_cleanup lib/kobject.c:704 [inline]
kobject_release lib/kobject.c:735 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x1c8/0x540 lib/kobject.c:752
put_device+0x1b/0x30 drivers/base/core.c:3029
hub_port_connect drivers/usb/core/hub.c:5059 [inline]
hub_port_connect_change drivers/usb/core/hub.c:5348 [inline]
port_event drivers/usb/core/hub.c:5494 [inline]
hub_event+0x1c93/0x4390 drivers/usb/core/hub.c:5576
process_one_work+0x94c/0x15f0 kernel/workqueue.c:2269
worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
kthread+0x392/0x470 kernel/kthread.c:292
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294
The buggy address belongs to the object at ffff8881caa52000
which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 24 bytes inside of
2048-byte region [ffff8881caa52000, ffff8881caa52800)
The buggy address belongs to the page:
page:ffffea00072a9400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea00072a9400 order:3 compound_mapcount:0 compound_pincount:0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 0000000000000000 0000000100000001 ffff8881da00c000
raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff8881caa51f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff8881caa51f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881caa52000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881caa52080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881caa52100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: KASAN: use-after-free Read in service_outstanding_interrupt 2020-08-07 12:19 KASAN: use-after-free Read in service_outstanding_interrupt syzbot @ 2020-12-18 3:21 ` syzbot 2021-01-04 16:28 ` Oliver Neukum [not found] ` <20201218082113.1238-1-hdanton@sina.com> 1 sibling, 1 reply; 8+ messages in thread From: syzbot @ 2020-12-18 3:21 UTC (permalink / raw) To: andreyknvl, gregkh, gustavoars, ingrassia, lee.jones, linux-kernel, linux-usb, oneukum, penguin-kernel, syzkaller-bugs syzbot has found a reproducer for the following issue on: HEAD commit: 5e60366d Merge tag 'fallthrough-fixes-clang-5.11-rc1' of g.. git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing console output: https://syzkaller.appspot.com/x/log.txt?x=12c5b623500000 kernel config: https://syzkaller.appspot.com/x/.config?x=5cea7506b7139727 dashboard link: https://syzkaller.appspot.com/bug?extid=9e04e2df4a32fb661daf compiler: gcc (GCC) 10.1.0-syz 20200507 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175adf07500000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1672680f500000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9e04e2df4a32fb661daf@syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in usb_submit_urb+0x1210/0x1560 drivers/usb/core/urb.c:383 Read of size 4 at addr ffff888101d21018 by task syz-executor166/4405 CPU: 0 PID: 4405 Comm: syz-executor166 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 usb_submit_urb+0x1210/0x1560 drivers/usb/core/urb.c:383 service_outstanding_interrupt.part.0+0x5f/0xa0 drivers/usb/class/cdc-wdm.c:470 service_outstanding_interrupt drivers/usb/class/cdc-wdm.c:465 [inline] wdm_read+0x9a0/0xbd0 drivers/usb/class/cdc-wdm.c:583 vfs_read+0x1b5/0x570 fs/read_write.c:494 ksys_read+0x12d/0x250 fs/read_write.c:634 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x44b529 Code: e8 bc b4 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 8b cb fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f2dfcb6ed98 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 000000000044b529 RDX: 0000000000001000 RSI: 0000000020001000 RDI: 0000000000000004 RBP: 00000000006dcc30 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c R13: 0142006002090100 R14: 04010040a4157d25 R15: 4000000200000112 Allocated by task 2632: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:682 [inline] usb_alloc_dev+0x51/0xef0 drivers/usb/core/usb.c:582 hub_port_connect drivers/usb/core/hub.c:5129 [inline] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] port_event drivers/usb/core/hub.c:5509 [inline] hub_event+0x1def/0x42d0 drivers/usb/core/hub.c:5591 process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x38c/0x460 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Freed by task 2181: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:352 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 slab_free mm/slub.c:3140 [inline] kfree+0xdb/0x3a0 mm/slub.c:4122 device_release+0x9f/0x240 drivers/base/core.c:1962 kobject_cleanup lib/kobject.c:705 [inline] kobject_release lib/kobject.c:736 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c8/0x540 lib/kobject.c:753 put_device+0x1b/0x30 drivers/base/core.c:3190 hub_port_connect drivers/usb/core/hub.c:5074 [inline] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] port_event drivers/usb/core/hub.c:5509 [inline] hub_event+0x1c8a/0x42d0 drivers/usb/core/hub.c:5591 process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x38c/0x460 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 The buggy address belongs to the object at ffff888101d21000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 24 bytes inside of 2048-byte region [ffff888101d21000, ffff888101d21800) The buggy address belongs to the page: page:0000000019761127 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101d20 head:0000000019761127 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x200000000010200(slab|head) raw: 0200000000010200 dead000000000100 dead000000000122 ffff888100042000 raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888101d20f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888101d20f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888101d21000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888101d21080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888101d21100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: KASAN: use-after-free Read in service_outstanding_interrupt 2020-12-18 3:21 ` syzbot @ 2021-01-04 16:28 ` Oliver Neukum 2021-01-04 16:44 ` syzbot 2021-01-05 4:50 ` 回复: " Zhang, Qiang 0 siblings, 2 replies; 8+ messages in thread From: Oliver Neukum @ 2021-01-04 16:28 UTC (permalink / raw) To: syzbot, andreyknvl, gregkh, gustavoars, ingrassia, lee.jones, linux-kernel, linux-usb, penguin-kernel, syzkaller-bugs Am Donnerstag, den 17.12.2020, 19:21 -0800 schrieb syzbot: > syzbot has found a reproducer for the following issue on: > > HEAD commit: 5e60366d Merge tag 'fallthrough-fixes-clang-5.11-rc1' of g.. > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > console output: https://syzkaller.appspot.com/x/log.txt?x=12c5b623500000 > kernel config: https://syzkaller.appspot.com/x/.config?x=5cea7506b7139727 > dashboard link: https://syzkaller.appspot.com/bug?extid=9e04e2df4a32fb661daf > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175adf07500000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1672680f500000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+9e04e2df4a32fb661daf@syzkaller.appspotmail.com #syz test: https://github.com/google/kasan.git 5e60366d From f51e3c5a202f3abc805edd64b21a68d29dd9d60e Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oneukum@suse.com> Date: Mon, 4 Jan 2021 17:26:33 +0100 Subject: [PATCH] cdc-wdm: poison URBs upon disconnect We have a chicken and egg issue between interrupt and work. This should break the cycle. Signed-off-by: Oliver Neukum <oneukum@suse.com> --- drivers/usb/class/cdc-wdm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 02d0cfd23bb2..14eddda35280 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -324,9 +324,9 @@ static void wdm_int_callback(struct urb *urb) static void kill_urbs(struct wdm_device *desc) { /* the order here is essential */ - usb_kill_urb(desc->command); - usb_kill_urb(desc->validity); - usb_kill_urb(desc->response); + usb_poison_urb(desc->command); + usb_poison_urb(desc->validity); + usb_poison_urb(desc->response); } static void free_urbs(struct wdm_device *desc) -- 2.26.2 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: KASAN: use-after-free Read in service_outstanding_interrupt 2021-01-04 16:28 ` Oliver Neukum @ 2021-01-04 16:44 ` syzbot 2021-01-05 4:50 ` 回复: " Zhang, Qiang 1 sibling, 0 replies; 8+ messages in thread From: syzbot @ 2021-01-04 16:44 UTC (permalink / raw) To: andreyknvl, gregkh, gustavoars, ingrassia, lee.jones, linux-kernel, linux-usb, penguin-kernel, syzkaller-bugs Hello, syzbot has tested the proposed patch but the reproducer is still triggering an issue: KASAN: use-after-free Read in service_outstanding_interrupt ================================================================== BUG: KASAN: use-after-free in usb_submit_urb+0x1210/0x1560 drivers/usb/core/urb.c:383 Read of size 4 at addr ffff888113e9f018 by task syz-executor.0/7799 CPU: 1 PID: 7799 Comm: syz-executor.0 Not tainted 5.10.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 __kasan_report mm/kasan/report.c:545 [inline] kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 usb_submit_urb+0x1210/0x1560 drivers/usb/core/urb.c:383 service_outstanding_interrupt.part.0+0x5f/0xa0 drivers/usb/class/cdc-wdm.c:470 service_outstanding_interrupt drivers/usb/class/cdc-wdm.c:465 [inline] wdm_read+0x9a0/0xbd0 drivers/usb/class/cdc-wdm.c:583 vfs_read+0x1b5/0x570 fs/read_write.c:494 ksys_read+0x12d/0x250 fs/read_write.c:634 do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e149 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fcce8099c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045e149 RDX: 0000000000001000 RSI: 0000000020001000 RDI: 0000000000000004 RBP: 000000000119c068 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119c034 R13: 00007fffc13967df R14: 00007fcce809a9c0 R15: 000000000119c034 Allocated by task 17: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track mm/kasan/common.c:56 [inline] __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 kmalloc include/linux/slab.h:552 [inline] kzalloc include/linux/slab.h:682 [inline] usb_alloc_dev+0x51/0xef0 drivers/usb/core/usb.c:582 hub_port_connect drivers/usb/core/hub.c:5129 [inline] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] port_event drivers/usb/core/hub.c:5509 [inline] hub_event+0x1def/0x42d0 drivers/usb/core/hub.c:5591 process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x38c/0x460 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Freed by task 2183: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:352 __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 slab_free_hook mm/slub.c:1544 [inline] slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 slab_free mm/slub.c:3140 [inline] kfree+0xdb/0x3a0 mm/slub.c:4122 device_release+0x9f/0x240 drivers/base/core.c:1962 kobject_cleanup lib/kobject.c:705 [inline] kobject_release lib/kobject.c:736 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1c8/0x540 lib/kobject.c:753 put_device+0x1b/0x30 drivers/base/core.c:3190 hub_port_connect drivers/usb/core/hub.c:5074 [inline] hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] port_event drivers/usb/core/hub.c:5509 [inline] hub_event+0x1c8a/0x42d0 drivers/usb/core/hub.c:5591 process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 kthread+0x38c/0x460 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 kasan_record_aux_stack+0xc0/0xf0 mm/kasan/generic.c:343 insert_work+0x48/0x370 kernel/workqueue.c:1331 __queue_work+0x5c3/0xf60 kernel/workqueue.c:1497 queue_work_on+0xc7/0xd0 kernel/workqueue.c:1524 kref_put include/linux/kref.h:65 [inline] tty_kref_put drivers/tty/tty_io.c:1493 [inline] release_tty+0x4e9/0x610 drivers/tty/tty_io.c:1530 tty_release_struct+0xb4/0xe0 drivers/tty/tty_io.c:1629 tty_release+0xc70/0x1210 drivers/tty/tty_io.c:1789 __fput+0x288/0x920 fs/file_table.c:280 task_work_run+0xdd/0x1a0 kernel/task_work.c:168 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop kernel/entry/common.c:174 [inline] exit_to_user_mode_prepare+0x186/0x190 kernel/entry/common.c:201 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff888113e9f000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 24 bytes inside of 2048-byte region [ffff888113e9f000, ffff888113e9f800) The buggy address belongs to the page: page:00000000e5a7bd64 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x113e98 head:00000000e5a7bd64 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x200000000010200(slab|head) raw: 0200000000010200 dead000000000100 dead000000000122 ffff888100042000 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888113e9ef00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888113e9ef80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888113e9f000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888113e9f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888113e9f100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Tested on: commit: 5e60366d Merge tag 'fallthrough-fixes-clang-5.11-rc1' of g.. git tree: https://github.com/google/kasan.git console output: https://syzkaller.appspot.com/x/log.txt?x=1755d077500000 kernel config: https://syzkaller.appspot.com/x/.config?x=5cea7506b7139727 dashboard link: https://syzkaller.appspot.com/bug?extid=9e04e2df4a32fb661daf compiler: gcc (GCC) 10.1.0-syz 20200507 patch: https://syzkaller.appspot.com/x/patch.diff?x=15e05e57500000 ^ permalink raw reply [flat|nested] 8+ messages in thread
* 回复: KASAN: use-after-free Read in service_outstanding_interrupt 2021-01-04 16:28 ` Oliver Neukum 2021-01-04 16:44 ` syzbot @ 2021-01-05 4:50 ` Zhang, Qiang 2021-01-05 10:51 ` Oliver Neukum 1 sibling, 1 reply; 8+ messages in thread From: Zhang, Qiang @ 2021-01-05 4:50 UTC (permalink / raw) To: Oliver Neukum, syzbot, andreyknvl, gregkh, gustavoars, ingrassia, lee.jones, linux-kernel, linux-usb, penguin-kernel@I-love.SAKURA.ne.jp, syzkaller-bugs ________________________________________ 发件人: Oliver Neukum <oneukum@suse.com> 发送时间: 2021年1月5日 0:28 收件人: syzbot; andreyknvl@google.com; gregkh@linuxfoundation.org; gustavoars@kernel.org; ingrassia@epigenesys.com; lee.jones@linaro.org; linux-kernel@vger.kernel.org; linux-usb@vger.kernel.org; penguin-kernel@I-love.SAKURA.ne.jp; syzkaller-bugs@googlegroups.com 主题: Re: KASAN: use-after-free Read in service_outstanding_interrupt Am Donnerstag, den 17.12.2020, 19:21 -0800 schrieb syzbot: > syzbot has found a reproducer for the following issue on: > > HEAD commit: 5e60366d Merge tag 'fallthrough-fixes-clang-5.11-rc1' of g.. > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > console output: https://syzkaller.appspot.com/x/log.txt?x=12c5b623500000 > kernel config: https://syzkaller.appspot.com/x/.config?x=5cea7506b7139727 > dashboard link: https://syzkaller.appspot.com/bug?extid=9e04e2df4a32fb661daf > compiler: gcc (GCC) 10.1.0-syz 20200507 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175adf07500000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1672680f500000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: >syzbot+9e04e2df4a32fb661daf@syzkaller.appspotmail.com > >#syz test: https://github.com/google/kasan.git 5e60366d > Hello Oliver this use-after-free still exists,It can be seen from calltrace that it is usb_device's object has been released when disconnect, can add a reference count to usb_device's object to avoid this problem diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc-wdm.c index 508b1c3f8b73..001cb93da6bf 100644 --- a/drivers/usb/class/cdc-wdm.c +++ b/drivers/usb/class/cdc-wdm.c @@ -106,6 +106,7 @@ struct wdm_device { struct list_head device_list; int (*manage_power)(struct usb_interface *, int); + struct usb_device *usb_dev; }; static struct usb_driver wdm_driver; @@ -338,6 +339,7 @@ static void free_urbs(struct wdm_device *desc) static void cleanup(struct wdm_device *desc) { + usb_put_dev(desc->usb_dev); kfree(desc->sbuf); kfree(desc->inbuf); kfree(desc->orq); @@ -855,6 +857,7 @@ static int wdm_create(struct usb_interface *intf, struct usb_endpoint_descripto r desc->intf = intf; INIT_WORK(&desc->rxwork, wdm_rxwork); INIT_WORK(&desc->service_outs_intr, service_interrupt_work); + desc->usb_dev = usb_get_dev(interface_to_usbdev(intf)); rv = -EINVAL; if (!usb_endpoint_is_int_in(ep)) >From f51e3c5a202f3abc805edd64b21a68d29dd9d60e Mon Sep 17 >00:00:00 2001 >From: Oliver Neukum <oneukum@suse.com> >Date: Mon, 4 Jan 2021 17:26:33 +0100 >Subject: [PATCH] cdc-wdm: poison URBs upon disconnect > >We have a chicken and egg issue between interrupt and work. >This should break the cycle. > >Signed-off-by: Oliver Neukum <oneukum@suse.com> >--- >drivers/usb/class/cdc-wdm.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > >diff --git a/drivers/usb/class/cdc-wdm.c b/drivers/usb/class/cdc->wdm.c >index 02d0cfd23bb2..14eddda35280 100644 >--- a/drivers/usb/class/cdc-wdm.c >+++ b/drivers/usb/class/cdc-wdm.c >@@ -324,9 +324,9 @@ static void wdm_int_callback(struct urb *urb) >static void kill_urbs(struct wdm_device *desc) > { > /* the order here is essential */ >- usb_kill_urb(desc->command); >- usb_kill_urb(desc->validity); >- usb_kill_urb(desc->response); >+ usb_poison_urb(desc->command); >+ usb_poison_urb(desc->validity); >+ usb_poison_urb(desc->response); > } > > static void free_urbs(struct wdm_device *desc) >-- >2.26.2 ^ permalink raw reply related [flat|nested] 8+ messages in thread
* Re: 回复: KASAN: use-after-free Read in service_outstanding_interrupt 2021-01-05 4:50 ` 回复: " Zhang, Qiang @ 2021-01-05 10:51 ` Oliver Neukum 0 siblings, 0 replies; 8+ messages in thread From: Oliver Neukum @ 2021-01-05 10:51 UTC (permalink / raw) To: Zhang, Qiang, syzbot, andreyknvl, gregkh, gustavoars, ingrassia, lee.jones, linux-kernel, linux-usb, penguin-kernel@I-love.SAKURA.ne.jp, syzkaller-bugs Am Dienstag, den 05.01.2021, 04:50 +0000 schrieb Zhang, Qiang: > > ________________________________________ > 发件人: Oliver Neukum <oneukum@suse.com> > 发送时间: 2021年1月5日 0:28 > 收件人: syzbot; andreyknvl@google.com; gregkh@linuxfoundation.org; gustavoars@kernel.org; ingrassia@epigenesys.com; lee.jones@linaro.org; linux-kernel@vger.kernel.org; linux-usb@vger.kernel.org; penguin-kernel@I-love.SAKURA.ne.jp; syzkaller-bugs@googlegroups.com > 主题: Re: KASAN: use-after-free Read in service_outstanding_interrupt > > Am Donnerstag, den 17.12.2020, 19:21 -0800 schrieb syzbot: > > syzbot has found a reproducer for the following issue on: > > > > HEAD commit: 5e60366d Merge tag 'fallthrough-fixes-clang-5.11-rc1' of g.. > > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > > console output: https://syzkaller.appspot.com/x/log.txt?x=12c5b623500000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=5cea7506b7139727 > > dashboard link: https://syzkaller.appspot.com/bug?extid=9e04e2df4a32fb661daf > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175adf07500000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1672680f500000 > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: >syzbot+9e04e2df4a32fb661daf@syzkaller.appspotmail.com > > > > #syz test: https://github.com/google/kasan.git 5e60366d > > > > Hello Oliver > > this use-after-free still exists,It can be seen from calltrace that it is > usb_device's object has been released when disconnect, > can add a reference count to usb_device's object to avoid this problem Hi, thanks for your analysis. I think you are correct in your analysis, but I am afraid your fix is not correct. The driver is submitting an URB to a disconnected device. Your fix would prevent a crash, which is definitely good, but we still cannot do that, because the device may be owned by another driver or usbfs at that time. Regards Oliver ^ permalink raw reply [flat|nested] 8+ messages in thread
[parent not found: <20201218082113.1238-1-hdanton@sina.com>]
* Re: KASAN: use-after-free Read in service_outstanding_interrupt [not found] ` <20201218082113.1238-1-hdanton@sina.com> @ 2020-12-18 8:28 ` Greg KH [not found] ` <20201218100134.1351-1-hdanton@sina.com> 1 sibling, 0 replies; 8+ messages in thread From: Greg KH @ 2020-12-18 8:28 UTC (permalink / raw) To: Hillf Danton Cc: syzbot, andreyknvl, gustavoars, ingrassia, lee.jones, linux-kernel, linux-usb, syzkaller-bugs On Fri, Dec 18, 2020 at 04:21:13PM +0800, Hillf Danton wrote: > On Thu, 17 Dec 2020 19:21:10 -0800 > > syzbot has found a reproducer for the following issue on: > > > > HEAD commit: 5e60366d Merge tag 'fallthrough-fixes-clang-5.11-rc1' of g.. > > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > > console output: https://syzkaller.appspot.com/x/log.txt?x=12c5b623500000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=5cea7506b7139727 > > dashboard link: https://syzkaller.appspot.com/bug?extid=9e04e2df4a32fb661daf > > compiler: gcc (GCC) 10.1.0-syz 20200507 > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175adf07500000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1672680f500000 > > > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > > Reported-by: syzbot+9e04e2df4a32fb661daf@syzkaller.appspotmail.com > > > > ================================================================== > > BUG: KASAN: use-after-free in usb_submit_urb+0x1210/0x1560 drivers/usb/core/urb.c:383 > > Read of size 4 at addr ffff888101d21018 by task syz-executor166/4405 > > > > CPU: 0 PID: 4405 Comm: syz-executor166 Not tainted 5.10.0-syzkaller #0 > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > > Call Trace: > > __dump_stack lib/dump_stack.c:79 [inline] > > dump_stack+0x107/0x163 lib/dump_stack.c:120 > > print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 > > __kasan_report mm/kasan/report.c:545 [inline] > > kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 > > usb_submit_urb+0x1210/0x1560 drivers/usb/core/urb.c:383 > > service_outstanding_interrupt.part.0+0x5f/0xa0 drivers/usb/class/cdc-wdm.c:470 > > service_outstanding_interrupt drivers/usb/class/cdc-wdm.c:465 [inline] > > wdm_read+0x9a0/0xbd0 drivers/usb/class/cdc-wdm.c:583 > > vfs_read+0x1b5/0x570 fs/read_write.c:494 > > ksys_read+0x12d/0x250 fs/read_write.c:634 > > do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 > > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > RIP: 0033:0x44b529 > > Code: e8 bc b4 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 8b cb fb ff c3 66 2e 0f 1f 84 00 00 00 00 > > RSP: 002b:00007f2dfcb6ed98 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 > > RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 000000000044b529 > > RDX: 0000000000001000 RSI: 0000000020001000 RDI: 0000000000000004 > > RBP: 00000000006dcc30 R08: 0000000000000000 R09: 0000000000000000 > > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c > > R13: 0142006002090100 R14: 04010040a4157d25 R15: 4000000200000112 > > > > Allocated by task 2632: > > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 > > kasan_set_track mm/kasan/common.c:56 [inline] > > __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 > > kmalloc include/linux/slab.h:552 [inline] > > kzalloc include/linux/slab.h:682 [inline] > > usb_alloc_dev+0x51/0xef0 drivers/usb/core/usb.c:582 > > hub_port_connect drivers/usb/core/hub.c:5129 [inline] > > hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] > > port_event drivers/usb/core/hub.c:5509 [inline] > > hub_event+0x1def/0x42d0 drivers/usb/core/hub.c:5591 > > process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 > > worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 > > kthread+0x38c/0x460 kernel/kthread.c:292 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 > > > > Freed by task 2181: > > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 > > kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 > > kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:352 > > __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 > > slab_free_hook mm/slub.c:1544 [inline] > > slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 > > slab_free mm/slub.c:3140 [inline] > > kfree+0xdb/0x3a0 mm/slub.c:4122 > > device_release+0x9f/0x240 drivers/base/core.c:1962 > > kobject_cleanup lib/kobject.c:705 [inline] > > kobject_release lib/kobject.c:736 [inline] > > kref_put include/linux/kref.h:65 [inline] > > kobject_put+0x1c8/0x540 lib/kobject.c:753 > > put_device+0x1b/0x30 drivers/base/core.c:3190 > > hub_port_connect drivers/usb/core/hub.c:5074 [inline] > > hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] > > port_event drivers/usb/core/hub.c:5509 [inline] > > hub_event+0x1c8a/0x42d0 drivers/usb/core/hub.c:5591 > > process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 > > worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 > > kthread+0x38c/0x460 kernel/kthread.c:292 > > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 > > > > The buggy address belongs to the object at ffff888101d21000 > > which belongs to the cache kmalloc-2k of size 2048 > > The buggy address is located 24 bytes inside of > > 2048-byte region [ffff888101d21000, ffff888101d21800) > > The buggy address belongs to the page: > > page:0000000019761127 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101d20 > > head:0000000019761127 order:3 compound_mapcount:0 compound_pincount:0 > > flags: 0x200000000010200(slab|head) > > raw: 0200000000010200 dead000000000100 dead000000000122 ffff888100042000 > > raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000 > > page dumped because: kasan: bad access detected > > > > Memory state around the buggy address: > > ffff888101d20f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > ffff888101d20f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > > >ffff888101d21000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ^ > > ffff888101d21080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ffff888101d21100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > > ================================================================== > > > Bail out without urb submitted if wdm device is disconnecting. > > --- a/drivers/usb/class/cdc-wdm.c > +++ b/drivers/usb/class/cdc-wdm.c > @@ -474,18 +474,25 @@ out: > return rv; > } > > -static ssize_t wdm_read > -(struct file *file, char __user *buffer, size_t count, loff_t *ppos) > +static ssize_t wdm_read(struct file *file, char __user *buffer, > + size_t count, loff_t *ppos) > { > int rv, cntr; > int i = 0; > struct wdm_device *desc = file->private_data; > > + if (test_bit(WDM_DISCONNECTING, &desc->flags)) > + return -ENODEV; > > rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ > if (rv < 0) > return -ERESTARTSYS; > > + if (test_bit(WDM_DISCONNECTING, &desc->flags)) { > + rv = -ENODEV; > + goto err; > + } Why test before the lock if you test right after the lock? and what happens if the bit is set right _after_ you test this? thanks, greg k-h ^ permalink raw reply [flat|nested] 8+ messages in thread
[parent not found: <20201218100134.1351-1-hdanton@sina.com>]
* Re: KASAN: use-after-free Read in service_outstanding_interrupt [not found] ` <20201218100134.1351-1-hdanton@sina.com> @ 2020-12-18 10:32 ` Greg KH 0 siblings, 0 replies; 8+ messages in thread From: Greg KH @ 2020-12-18 10:32 UTC (permalink / raw) To: Hillf Danton Cc: syzbot, andreyknvl, gustavoars, ingrassia, lee.jones, linux-kernel, linux-usb, syzkaller-bugs On Fri, Dec 18, 2020 at 06:01:34PM +0800, Hillf Danton wrote: > On Fri, 18 Dec 2020 09:28:16 +0100 Greg KH wrote: > >On Fri, Dec 18, 2020 at 04:21:13PM +0800, Hillf Danton wrote: > >> On Thu, 17 Dec 2020 19:21:10 -0800 > >> > syzbot has found a reproducer for the following issue on: > >> > > >> > HEAD commit: 5e60366d Merge tag 'fallthrough-fixes-clang-5.11-rc1' of g.. > >> > git tree: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing > >> > console output: https://syzkaller.appspot.com/x/log.txt?x=12c5b623500000 > >> > kernel config: https://syzkaller.appspot.com/x/.config?x=5cea7506b7139727 > >> > dashboard link: https://syzkaller.appspot.com/bug?extid=9e04e2df4a32fb661daf > >> > compiler: gcc (GCC) 10.1.0-syz 20200507 > >> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=175adf07500000 > >> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1672680f500000 > >> > > >> > IMPORTANT: if you fix the issue, please add the following tag to the commit: > >> > Reported-by: syzbot+9e04e2df4a32fb661daf@syzkaller.appspotmail.com > >> > > >> > ================================================================== > >> > BUG: KASAN: use-after-free in usb_submit_urb+0x1210/0x1560 drivers/usb/core/urb.c:383 > >> > Read of size 4 at addr ffff888101d21018 by task syz-executor166/4405 > >> > > >> > CPU: 0 PID: 4405 Comm: syz-executor166 Not tainted 5.10.0-syzkaller #0 > >> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > >> > Call Trace: > >> > __dump_stack lib/dump_stack.c:79 [inline] > >> > dump_stack+0x107/0x163 lib/dump_stack.c:120 > >> > print_address_description.constprop.0.cold+0xae/0x4c8 mm/kasan/report.c:385 > >> > __kasan_report mm/kasan/report.c:545 [inline] > >> > kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562 > >> > usb_submit_urb+0x1210/0x1560 drivers/usb/core/urb.c:383 > >> > service_outstanding_interrupt.part.0+0x5f/0xa0 drivers/usb/class/cdc-wdm.c:470 > >> > service_outstanding_interrupt drivers/usb/class/cdc-wdm.c:465 [inline] > >> > wdm_read+0x9a0/0xbd0 drivers/usb/class/cdc-wdm.c:583 > >> > vfs_read+0x1b5/0x570 fs/read_write.c:494 > >> > ksys_read+0x12d/0x250 fs/read_write.c:634 > >> > do_syscall_64+0x2d/0x40 arch/x86/entry/common.c:46 > >> > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > >> > RIP: 0033:0x44b529 > >> > Code: e8 bc b4 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 8b cb fb ff c3 66 2e 0f 1f 84 00 00 00 00 > >> > RSP: 002b:00007f2dfcb6ed98 EFLAGS: 00000246 ORIG_RAX: 0000000000000000 > >> > RAX: ffffffffffffffda RBX: 00000000006dcc38 RCX: 000000000044b529 > >> > RDX: 0000000000001000 RSI: 0000000020001000 RDI: 0000000000000004 > >> > RBP: 00000000006dcc30 R08: 0000000000000000 R09: 0000000000000000 > >> > R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dcc3c > >> > R13: 0142006002090100 R14: 04010040a4157d25 R15: 4000000200000112 > >> > > >> > Allocated by task 2632: > >> > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 > >> > kasan_set_track mm/kasan/common.c:56 [inline] > >> > __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:461 > >> > kmalloc include/linux/slab.h:552 [inline] > >> > kzalloc include/linux/slab.h:682 [inline] > >> > usb_alloc_dev+0x51/0xef0 drivers/usb/core/usb.c:582 > >> > hub_port_connect drivers/usb/core/hub.c:5129 [inline] > >> > hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] > >> > port_event drivers/usb/core/hub.c:5509 [inline] > >> > hub_event+0x1def/0x42d0 drivers/usb/core/hub.c:5591 > >> > process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 > >> > worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 > >> > kthread+0x38c/0x460 kernel/kthread.c:292 > >> > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 > >> > > >> > Freed by task 2181: > >> > kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48 > >> > kasan_set_track+0x1c/0x30 mm/kasan/common.c:56 > >> > kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:352 > >> > __kasan_slab_free+0x102/0x140 mm/kasan/common.c:422 > >> > slab_free_hook mm/slub.c:1544 [inline] > >> > slab_free_freelist_hook+0x5d/0x150 mm/slub.c:1577 > >> > slab_free mm/slub.c:3140 [inline] > >> > kfree+0xdb/0x3a0 mm/slub.c:4122 > >> > device_release+0x9f/0x240 drivers/base/core.c:1962 > >> > kobject_cleanup lib/kobject.c:705 [inline] > >> > kobject_release lib/kobject.c:736 [inline] > >> > kref_put include/linux/kref.h:65 [inline] > >> > kobject_put+0x1c8/0x540 lib/kobject.c:753 > >> > put_device+0x1b/0x30 drivers/base/core.c:3190 > >> > hub_port_connect drivers/usb/core/hub.c:5074 [inline] > >> > hub_port_connect_change drivers/usb/core/hub.c:5363 [inline] > >> > port_event drivers/usb/core/hub.c:5509 [inline] > >> > hub_event+0x1c8a/0x42d0 drivers/usb/core/hub.c:5591 > >> > process_one_work+0x98d/0x15c0 kernel/workqueue.c:2275 > >> > worker_thread+0x64c/0x1120 kernel/workqueue.c:2421 > >> > kthread+0x38c/0x460 kernel/kthread.c:292 > >> > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 > >> > > >> > The buggy address belongs to the object at ffff888101d21000 > >> > which belongs to the cache kmalloc-2k of size 2048 > >> > The buggy address is located 24 bytes inside of > >> > 2048-byte region [ffff888101d21000, ffff888101d21800) > >> > The buggy address belongs to the page: > >> > page:0000000019761127 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101d20 > >> > head:0000000019761127 order:3 compound_mapcount:0 compound_pincount:0 > >> > flags: 0x200000000010200(slab|head) > >> > raw: 0200000000010200 dead000000000100 dead000000000122 ffff888100042000 > >> > raw: 0000000000000000 0000000080080008 00000001ffffffff 0000000000000000 > >> > page dumped because: kasan: bad access detected > >> > > >> > Memory state around the buggy address: > >> > ffff888101d20f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > >> > ffff888101d20f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > >> > >ffff888101d21000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > >> > ^ > >> > ffff888101d21080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > >> > ffff888101d21100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > >> > ================================================================== > >> > > >> Bail out without urb submitted if wdm device is disconnecting. > >> > >> --- a/drivers/usb/class/cdc-wdm.c > >> +++ b/drivers/usb/class/cdc-wdm.c > >> @@ -474,18 +474,25 @@ out: > >> return rv; > >> } > >> > >> -static ssize_t wdm_read > >> -(struct file *file, char __user *buffer, size_t count, loff_t *ppos) > >> +static ssize_t wdm_read(struct file *file, char __user *buffer, > >> + size_t count, loff_t *ppos) > >> { > >> int rv, cntr; > >> int i = 0; > >> struct wdm_device *desc = file->private_data; > >> > >> + if (test_bit(WDM_DISCONNECTING, &desc->flags)) > >> + return -ENODEV; > >> > >> rv = mutex_lock_interruptible(&desc->rlock); /*concurrent reads */ > >> if (rv < 0) > >> return -ERESTARTSYS; > >> > >> + if (test_bit(WDM_DISCONNECTING, &desc->flags)) { > >> + rv = -ENODEV; > >> + goto err; > >> + } > > > >Why test before the lock if you test right after the lock? > > Any test is supposed to make sense. I do not understand. I am trying to say, why do you even have the test outside of the lock as that makes no sense? > >and what happens if the bit is set right _after_ you test this? > > Your question explains the above double test. No it doesn't :) > If we get desc->rlock and fail to test WDM_DISCONNECTING in the > read path then we are safe because the same lock is acquired also > in the disconnect path. Then only check the bit _when_ the lock is held. Otherwise it is a pointless check. thanks, greg k-h ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2021-01-05 10:52 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-08-07 12:19 KASAN: use-after-free Read in service_outstanding_interrupt syzbot 2020-12-18 3:21 ` syzbot 2021-01-04 16:28 ` Oliver Neukum 2021-01-04 16:44 ` syzbot 2021-01-05 4:50 ` 回复: " Zhang, Qiang 2021-01-05 10:51 ` Oliver Neukum [not found] ` <20201218082113.1238-1-hdanton@sina.com> 2020-12-18 8:28 ` Greg KH [not found] ` <20201218100134.1351-1-hdanton@sina.com> 2020-12-18 10:32 ` Greg KH
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