* possible deadlock in start_this_handle
@ 2018-09-07 8:38 syzbot
2018-09-07 9:38 ` Jan Kara
0 siblings, 1 reply; 3+ messages in thread
From: syzbot @ 2018-09-07 8:38 UTC (permalink / raw)
To: jack, linux-ext4, linux-kernel, syzkaller-bugs, tytso
Hello,
syzbot found the following crash on:
HEAD commit: ca16eb342ebe Merge tag 'for-linus-20180906' of git://git.k..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=129e80ae400000
kernel config: https://syzkaller.appspot.com/x/.config?x=6c9564cd177daf0c
dashboard link: https://syzkaller.appspot.com/bug?extid=fe49aec75e221f9b093e
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
Unfortunately, I don't have any reproducer for this crash yet.
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+fe49aec75e221f9b093e@syzkaller.appspotmail.com
ISOFS: Unable to identify CD-ROM format.
======================================================
WARNING: possible circular locking dependency detected
4.19.0-rc2+ #2 Not tainted
------------------------------------------------------
kswapd0/1430 is trying to acquire lock:
0000000085a9412e (jbd2_handle){++++}, at: start_this_handle+0x589/0x1260
fs/jbd2/transaction.c:383
but task is already holding lock:
00000000af99a839 (fs_reclaim){+.+.}, at: __page_frag_cache_refill
mm/page_alloc.c:4476 [inline]
00000000af99a839 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30
mm/page_alloc.c:4505
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (fs_reclaim){+.+.}:
__fs_reclaim_acquire mm/page_alloc.c:3728 [inline]
fs_reclaim_acquire.part.98+0x24/0x30 mm/page_alloc.c:3739
fs_reclaim_acquire+0x14/0x20 mm/page_alloc.c:3740
slab_pre_alloc_hook mm/slab.h:418 [inline]
slab_alloc mm/slab.c:3378 [inline]
kmem_cache_alloc_trace+0x2d/0x730 mm/slab.c:3618
kmalloc include/linux/slab.h:513 [inline]
kzalloc include/linux/slab.h:707 [inline]
smk_fetch.part.24+0x5a/0xf0 security/smack/smack_lsm.c:273
smk_fetch security/smack/smack_lsm.c:3548 [inline]
smack_d_instantiate+0x946/0xea0 security/smack/smack_lsm.c:3502
security_d_instantiate+0x5c/0xf0 security/security.c:1287
d_instantiate+0x5e/0xa0 fs/dcache.c:1870
shmem_mknod+0x189/0x1f0 mm/shmem.c:2812
vfs_mknod+0x447/0x800 fs/namei.c:3719
handle_create+0x1ff/0x7c0 drivers/base/devtmpfs.c:211
handle drivers/base/devtmpfs.c:374 [inline]
devtmpfsd+0x27f/0x4c0 drivers/base/devtmpfs.c:400
kthread+0x35a/0x420 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
-> #1 (&isp->smk_lock){+.+.}:
__mutex_lock_common kernel/locking/mutex.c:925 [inline]
__mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
smack_d_instantiate+0x130/0xea0 security/smack/smack_lsm.c:3369
security_d_instantiate+0x5c/0xf0 security/security.c:1287
d_instantiate_new+0x7e/0x160 fs/dcache.c:1889
ext4_add_nondir+0x81/0x90 fs/ext4/namei.c:2415
ext4_symlink+0x761/0x1170 fs/ext4/namei.c:3162
vfs_symlink+0x37a/0x5d0 fs/namei.c:4127
do_symlinkat+0x242/0x2d0 fs/namei.c:4154
__do_sys_symlink fs/namei.c:4173 [inline]
__se_sys_symlink fs/namei.c:4171 [inline]
__x64_sys_symlink+0x59/0x80 fs/namei.c:4171
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
-> #0 (jbd2_handle){++++}:
lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901
start_this_handle+0x5c0/0x1260 fs/jbd2/transaction.c:385
jbd2__journal_start+0x3c9/0x9f0 fs/jbd2/transaction.c:439
__ext4_journal_start_sb+0x18d/0x590 fs/ext4/ext4_jbd2.c:81
__ext4_journal_start fs/ext4/ext4_jbd2.h:311 [inline]
ext4_dirty_inode+0x62/0xc0 fs/ext4/inode.c:6021
__mark_inode_dirty+0x760/0x1300 fs/fs-writeback.c:2129
mark_inode_dirty_sync include/linux/fs.h:2072 [inline]
iput+0x131/0xa00 fs/inode.c:1570
dentry_unlink_inode+0x461/0x5e0 fs/dcache.c:374
__dentry_kill+0x44c/0x7a0 fs/dcache.c:566
shrink_dentry_list+0x322/0x7c0 fs/dcache.c:1079
prune_dcache_sb+0x12f/0x1c0 fs/dcache.c:1171
super_cache_scan+0x270/0x480 fs/super.c:102
do_shrink_slab+0x4ba/0xbb0 mm/vmscan.c:536
shrink_slab+0x389/0x8c0 mm/vmscan.c:686
shrink_node+0x429/0x16a0 mm/vmscan.c:2735
kswapd_shrink_node mm/vmscan.c:3457 [inline]
balance_pgdat+0x7ca/0x1010 mm/vmscan.c:3567
kswapd+0x82f/0x11e0 mm/vmscan.c:3789
kthread+0x35a/0x420 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
other info that might help us debug this:
Chain exists of:
jbd2_handle --> &isp->smk_lock --> fs_reclaim
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(fs_reclaim);
lock(&isp->smk_lock);
lock(fs_reclaim);
lock(jbd2_handle);
*** DEADLOCK ***
3 locks held by kswapd0/1430:
#0: 00000000af99a839 (fs_reclaim){+.+.}, at: __page_frag_cache_refill
mm/page_alloc.c:4476 [inline]
#0: 00000000af99a839 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30
mm/page_alloc.c:4505
#1: 000000003e78ad93 (shrinker_rwsem){++++}, at: shrink_slab+0x207/0x8c0
mm/vmscan.c:676
#2: 00000000e742ec1a (&type->s_umount_key#28){++++}, at:
trylock_super+0x22/0x110 fs/super.c:412
stack backtrace:
CPU: 1 PID: 1430 Comm: kswapd0 Not tainted 4.19.0-rc2+ #2
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+0x1c9/0x2b4 lib/dump_stack.c:113
print_circular_bug.isra.34.cold.55+0x1bd/0x27d
kernel/locking/lockdep.c:1222
check_prev_add kernel/locking/lockdep.c:1862 [inline]
check_prevs_add kernel/locking/lockdep.c:1975 [inline]
validate_chain kernel/locking/lockdep.c:2416 [inline]
__lock_acquire+0x3449/0x5020 kernel/locking/lockdep.c:3412
lock_acquire+0x1e4/0x4f0 kernel/locking/lockdep.c:3901
start_this_handle+0x5c0/0x1260 fs/jbd2/transaction.c:385
jbd2__journal_start+0x3c9/0x9f0 fs/jbd2/transaction.c:439
__ext4_journal_start_sb+0x18d/0x590 fs/ext4/ext4_jbd2.c:81
__ext4_journal_start fs/ext4/ext4_jbd2.h:311 [inline]
ext4_dirty_inode+0x62/0xc0 fs/ext4/inode.c:6021
__mark_inode_dirty+0x760/0x1300 fs/fs-writeback.c:2129
mark_inode_dirty_sync include/linux/fs.h:2072 [inline]
iput+0x131/0xa00 fs/inode.c:1570
dentry_unlink_inode+0x461/0x5e0 fs/dcache.c:374
__dentry_kill+0x44c/0x7a0 fs/dcache.c:566
shrink_dentry_list+0x322/0x7c0 fs/dcache.c:1079
prune_dcache_sb+0x12f/0x1c0 fs/dcache.c:1171
super_cache_scan+0x270/0x480 fs/super.c:102
do_shrink_slab+0x4ba/0xbb0 mm/vmscan.c:536
shrink_slab+0x389/0x8c0 mm/vmscan.c:686
shrink_node+0x429/0x16a0 mm/vmscan.c:2735
kswapd_shrink_node mm/vmscan.c:3457 [inline]
balance_pgdat+0x7ca/0x1010 mm/vmscan.c:3567
kswapd+0x82f/0x11e0 mm/vmscan.c:3789
kthread+0x35a/0x420 kernel/kthread.c:246
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "
esize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "
esize="
ISOFS: Unable to identify CD-ROM format.
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 1 PID: 323 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #2
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+0x1c9/0x2b4 lib/dump_stack.c:113
handle_userfault.cold.33+0x43/0x52 fs/userfaultfd.c:432
do_anonymous_page mm/memory.c:3164 [inline]
handle_pte_fault mm/memory.c:3981 [inline]
__handle_mm_fault+0x389e/0x4350 mm/memory.c:4107
handle_mm_fault+0x53e/0xc80 mm/memory.c:4144
__do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1395
do_page_fault+0xf6/0x7a4 arch/x86/mm/fault.c:1470
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1161
RIP: 0010:copy_user_generic_unrolled+0x86/0xc0
arch/x86/lib/copy_user_64.S:65
Code: 4c 8b 5e 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76
40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 <4c> 8b 06 4c 89
07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10
RSP: 0018:ffff880164f67700 EFLAGS: 00010203
RAX: 0000000000000004 RBX: 000000000000000c RCX: 0000000000000001
RDX: 0000000000000004 RSI: 0000000020013ff4 RDI: ffff8801c49a14a0
RBP: ffff880164f67738 R08: ffffed0038934296 R09: ffffed0038934294
R10: ffffed0038934295 R11: 0000000000000003 R12: 0000000020014000
R13: 0000000020013ff4 R14: ffff8801c49a14a0 R15: 00007ffffffff000
copy_from_user include/linux/uaccess.h:147 [inline]
ip_options_get_from_user+0x8d/0xf0 net/ipv4/ip_options.c:537
do_ip_setsockopt.isra.13+0x1ba6/0x3e70 net/ipv4/ip_sockglue.c:655
ip_setsockopt+0x4c/0x140 net/ipv4/ip_sockglue.c:1249
tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:3062
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038
__sys_setsockopt+0x1c5/0x3b0 net/socket.c:1900
__do_sys_setsockopt net/socket.c:1911 [inline]
__se_sys_setsockopt net/socket.c:1908 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1908
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: fd 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f20d1b5ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f20d1b5f6d4 RCX: 0000000000457099
RDX: 0000000000000004 RSI: 0900000000000000 RDI: 0000000000000006
RBP: 00000000009300a0 R08: 000000000000000c R09: 0000000000000000
R10: 0000000020013ff4 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d58c8 R14: 00000000004c982a R15: 0000000000000000
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "%esize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "%esize="
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "xesize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "xesize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 0 PID: 480 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #2
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+0x1c9/0x2b4 lib/dump_stack.c:113
handle_userfault.cold.33+0x43/0x52 fs/userfaultfd.c:432
do_anonymous_page mm/memory.c:3164 [inline]
handle_pte_fault mm/memory.c:3981 [inline]
__handle_mm_fault+0x389e/0x4350 mm/memory.c:4107
handle_mm_fault+0x53e/0xc80 mm/memory.c:4144
ISOFS: Unable to identify CD-ROM format.
__do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1395
do_page_fault+0xf6/0x7a4 arch/x86/mm/fault.c:1470
ISOFS: Unable to identify CD-ROM format.
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1161
RIP: 0010:copy_user_generic_unrolled+0x86/0xc0
arch/x86/lib/copy_user_64.S:65
Code: 4c 8b 5e 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76
40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 <4c> 8b 06 4c 89
07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10
RSP: 0018:ffff880166f67700 EFLAGS: 00010203
RAX: 0000000000000004 RBX: 000000000000000c RCX: 0000000000000001
RDX: 0000000000000004 RSI: 0000000020013ff4 RDI: ffff8801c04690a0
RBP: ffff880166f67738 R08: ffffed003808d216 R09: ffffed003808d214
R10: ffffed003808d215 R11: 0000000000000003 R12: 0000000020014000
R13: 0000000020013ff4 R14: ffff8801c04690a0 R15: 00007ffffffff000
copy_from_user include/linux/uaccess.h:147 [inline]
ip_options_get_from_user+0x8d/0xf0 net/ipv4/ip_options.c:537
do_ip_setsockopt.isra.13+0x1ba6/0x3e70 net/ipv4/ip_sockglue.c:655
ISOFS: Unable to identify CD-ROM format.
ip_setsockopt+0x4c/0x140 net/ipv4/ip_sockglue.c:1249
tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:3062
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038
__sys_setsockopt+0x1c5/0x3b0 net/socket.c:1900
__do_sys_setsockopt net/socket.c:1911 [inline]
__se_sys_setsockopt net/socket.c:1908 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1908
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: fd 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f20d1b5ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f20d1b5f6d4 RCX: 0000000000457099
RDX: 0000000000000004 RSI: 0200000000000000 RDI: 0000000000000006
RBP: 00000000009300a0 R08: 000000000000000c R09: 0000000000000000
R10: 0000000020013ff4 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d58c8 R14: 00000000004c982a R15: 0000000000000000
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "r%size="
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "r%size="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "rxsize="
ISOFS: Unable to identify CD-ROM format.
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 0 PID: 618 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #2
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+0x1c9/0x2b4 lib/dump_stack.c:113
handle_userfault.cold.33+0x43/0x52 fs/userfaultfd.c:432
do_anonymous_page mm/memory.c:3164 [inline]
handle_pte_fault mm/memory.c:3981 [inline]
__handle_mm_fault+0x389e/0x4350 mm/memory.c:4107
ISOFS: Unable to identify CD-ROM format.
handle_mm_fault+0x53e/0xc80 mm/memory.c:4144
__do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1395
ISOFS: Unable to identify CD-ROM format.
do_page_fault+0xf6/0x7a4 arch/x86/mm/fault.c:1470
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1161
RIP: 0010:copy_user_generic_unrolled+0x86/0xc0
arch/x86/lib/copy_user_64.S:65
Code: 4c 8b 5e 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76
40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 <4c> 8b 06 4c 89
07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10
RSP: 0018:ffff880166f87700 EFLAGS: 00010203
RAX: 0000000000000004 RBX: 000000000000000c RCX: 0000000000000001
RDX: 0000000000000004 RSI: 0000000020013ff4 RDI: ffff8800136c75a0
RBP: ffff880166f87738 R08: ffffed00026d8eb6 R09: ffffed00026d8eb4
R10: ffffed00026d8eb5 R11: 0000000000000003 R12: 0000000020014000
R13: 0000000020013ff4 R14: ffff8800136c75a0 R15: 00007ffffffff000
copy_from_user include/linux/uaccess.h:147 [inline]
ip_options_get_from_user+0x8d/0xf0 net/ipv4/ip_options.c:537
do_ip_setsockopt.isra.13+0x1ba6/0x3e70 net/ipv4/ip_sockglue.c:655
ip_setsockopt+0x4c/0x140 net/ipv4/ip_sockglue.c:1249
tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:3062
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038
__sys_setsockopt+0x1c5/0x3b0 net/socket.c:1900
ISOFS: Unable to identify CD-ROM format.
__do_sys_setsockopt net/socket.c:1911 [inline]
__se_sys_setsockopt net/socket.c:1908 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1908
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: fd 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f20d1b5ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f20d1b5f6d4 RCX: 0000000000457099
RDX: 0000000000000004 RSI: 6000000000000000 RDI: 0000000000000006
RBP: 00000000009300a0 R08: 000000000000000c R09: 0000000000000000
R10: 0000000020013ff4 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d58c8 R14: 00000000004c982a R15: 0000000000000000
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "rxsize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
isofs_fill_super: bread failed, dev=loop6, iso_blknum=32, block=64
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "r
size="
ISOFS: Unable to identify CD-ROM format.
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 0 PID: 728 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #2
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+0x1c9/0x2b4 lib/dump_stack.c:113
handle_userfault.cold.33+0x43/0x52 fs/userfaultfd.c:432
ISOFS: Unable to identify CD-ROM format.
do_anonymous_page mm/memory.c:3164 [inline]
handle_pte_fault mm/memory.c:3981 [inline]
__handle_mm_fault+0x389e/0x4350 mm/memory.c:4107
handle_mm_fault+0x53e/0xc80 mm/memory.c:4144
__do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1395
do_page_fault+0xf6/0x7a4 arch/x86/mm/fault.c:1470
ISOFS: Unable to identify CD-ROM format.
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1161
RIP: 0010:copy_user_generic_unrolled+0x86/0xc0
arch/x86/lib/copy_user_64.S:65
Code: 4c 8b 5e 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76
40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 <4c> 8b 06 4c 89
07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10
RSP: 0018:ffff88015ba57700 EFLAGS: 00010203
RAX: 0000000000000004 RBX: 000000000000000c RCX: 0000000000000001
RDX: 0000000000000004 RSI: 0000000020013ff4 RDI: ffff8801d7f72220
RBP: ffff88015ba57738 R08: ffffed003afee446 R09: ffffed003afee444
R10: ffffed003afee445 R11: 0000000000000003 R12: 0000000020014000
R13: 0000000020013ff4 R14: ffff8801d7f72220 R15: 00007ffffffff000
copy_from_user include/linux/uaccess.h:147 [inline]
ip_options_get_from_user+0x8d/0xf0 net/ipv4/ip_options.c:537
do_ip_setsockopt.isra.13+0x1ba6/0x3e70 net/ipv4/ip_sockglue.c:655
ip_setsockopt+0x4c/0x140 net/ipv4/ip_sockglue.c:1249
tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:3062
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038
__sys_setsockopt+0x1c5/0x3b0 net/socket.c:1900
__do_sys_setsockopt net/socket.c:1911 [inline]
__se_sys_setsockopt net/socket.c:1908 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1908
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
ISOFS: Unable to identify CD-ROM format.
Code: fd 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f20d1b5ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f20d1b5f6d4 RCX: 0000000000457099
RDX: 0000000000000004 RSI: ffffffff00000000 RDI: 0000000000000006
RBP: 00000000009300a0 R08: 000000000000000c R09: 0000000000000000
R10: 0000000020013ff4 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d58c8 R14: 00000000004c982a R15: 0000000000000000
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "r
size="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "reaize="
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "reaize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "rezize="
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "rezize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 0 PID: 938 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #2
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+0x1c9/0x2b4 lib/dump_stack.c:113
handle_userfault.cold.33+0x43/0x52 fs/userfaultfd.c:432
do_anonymous_page mm/memory.c:3164 [inline]
handle_pte_fault mm/memory.c:3981 [inline]
__handle_mm_fault+0x389e/0x4350 mm/memory.c:4107
handle_mm_fault+0x53e/0xc80 mm/memory.c:4144
__do_page_fault+0x620/0xe50 arch/x86/mm/fault.c:1395
do_page_fault+0xf6/0x7a4 arch/x86/mm/fault.c:1470
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1161
RIP: 0010:copy_user_generic_unrolled+0x86/0xc0
arch/x86/lib/copy_user_64.S:65
Code: 4c 8b 5e 38 4c 89 47 20 4c 89 4f 28 4c 89 57 30 4c 89 5f 38 48 8d 76
40 48 8d 7f 40 ff c9 75 b6 89 d1 83 e2 07 c1 e9 03 74 12 <4c> 8b 06 4c 89
07 48 8d 76 08 48 8d 7f 08 ff c9 75 ee 21 d2 74 10
RSP: 0018:ffff88001c8ff700 EFLAGS: 00010203
RAX: 0000000000000004 RBX: 000000000000000c RCX: 0000000000000001
RDX: 0000000000000004 RSI: 0000000020013ff4 RDI: ffff880164d4e1a0
RBP: ffff88001c8ff738 R08: ffffed002c9a9c36 R09: ffffed002c9a9c34
R10: ffffed002c9a9c35 R11: 0000000000000003 R12: 0000000020014000
R13: 0000000020013ff4 R14: ffff880164d4e1a0 R15: 00007ffffffff000
copy_from_user include/linux/uaccess.h:147 [inline]
ip_options_get_from_user+0x8d/0xf0 net/ipv4/ip_options.c:537
do_ip_setsockopt.isra.13+0x1ba6/0x3e70 net/ipv4/ip_sockglue.c:655
ip_setsockopt+0x4c/0x140 net/ipv4/ip_sockglue.c:1249
tcp_setsockopt+0x93/0xe0 net/ipv4/tcp.c:3062
sock_common_setsockopt+0x9a/0xe0 net/core/sock.c:3038
__sys_setsockopt+0x1c5/0x3b0 net/socket.c:1900
__do_sys_setsockopt net/socket.c:1911 [inline]
__se_sys_setsockopt net/socket.c:1908 [inline]
__x64_sys_setsockopt+0xbe/0x150 net/socket.c:1908
do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457099
Code: fd 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 cb b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f20d1b5ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f20d1b5f6d4 RCX: 0000000000457099
RDX: 0000000000000004 RSI: 2000000000000000 RDI: 0000000000000006
RBP: 00000000009300a0 R08: 000000000000000c R09: 0000000000000000
R10: 0000000020013ff4 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004d58c8 R14: 00000000004c982a R15: 0000000000000000
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "rexize="
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "rexize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "re-ize="
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "re-ize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "reuize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "re
ize="
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "re
ize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "rehize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "rehize="
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "reyize="
ISOFS: Unable to identify CD-ROM format.
REISERFS warning (device loop4): super-6502 reiserfs_getopt: unknown mount
option "reyize="
ISOFS: Unable to identify CD-ROM format.
FAULT_FLAG_ALLOW_RETRY missing 30
CPU: 1 PID: 1343 Comm: syz-executor0 Not tainted 4.19.0-rc2+ #2
---
This bug 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 bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: possible deadlock in start_this_handle
2018-09-07 8:38 possible deadlock in start_this_handle syzbot
@ 2018-09-07 9:38 ` Jan Kara
0 siblings, 0 replies; 3+ messages in thread
From: Jan Kara @ 2018-09-07 9:38 UTC (permalink / raw)
To: syzbot
Cc: jack, linux-ext4, linux-kernel, syzkaller-bugs, tytso, mhocko,
Casey Schaufler, linux-security-module
On Fri 07-09-18 01:38:03, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: ca16eb342ebe Merge tag 'for-linus-20180906' of git://git.k..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=129e80ae400000
> kernel config: https://syzkaller.appspot.com/x/.config?x=6c9564cd177daf0c
> dashboard link: https://syzkaller.appspot.com/bug?extid=fe49aec75e221f9b093e
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+fe49aec75e221f9b093e@syzkaller.appspotmail.com
>
So this looks like a false positive due to Michal's memalloc_nofs_save()
work and lockdep not being clever enough. And it actually nicely shows how
Michal's work prevents real deadlock possibilities.
> ======================================================
> WARNING: possible circular locking dependency detected
> 4.19.0-rc2+ #2 Not tainted
> ------------------------------------------------------
> kswapd0/1430 is trying to acquire lock:
> 0000000085a9412e (jbd2_handle){++++}, at: start_this_handle+0x589/0x1260
> fs/jbd2/transaction.c:383
>
> but task is already holding lock:
> 00000000af99a839 (fs_reclaim){+.+.}, at: __page_frag_cache_refill
> mm/page_alloc.c:4476 [inline]
> 00000000af99a839 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30
> mm/page_alloc.c:4505
So lockdep is complaining about kswapd starting a transaction during fs
reclaim. It should be OK to do so so let's see why lockdep thinks starting
a transaction in fs reclaim is not good.
> the existing dependency chain (in reverse order) is:
>
> -> #2 (fs_reclaim){+.+.}:
> __fs_reclaim_acquire mm/page_alloc.c:3728 [inline]
> fs_reclaim_acquire.part.98+0x24/0x30 mm/page_alloc.c:3739
> fs_reclaim_acquire+0x14/0x20 mm/page_alloc.c:3740
> slab_pre_alloc_hook mm/slab.h:418 [inline]
> slab_alloc mm/slab.c:3378 [inline]
> kmem_cache_alloc_trace+0x2d/0x730 mm/slab.c:3618
Here smack is doing GFP_KERNEL allocation. In this case it gets called from
shmfs which is OK with doing fs reclaim... <see below>
> kmalloc include/linux/slab.h:513 [inline]
> kzalloc include/linux/slab.h:707 [inline]
> smk_fetch.part.24+0x5a/0xf0 security/smack/smack_lsm.c:273
> smk_fetch security/smack/smack_lsm.c:3548 [inline]
> smack_d_instantiate+0x946/0xea0 security/smack/smack_lsm.c:3502
> security_d_instantiate+0x5c/0xf0 security/security.c:1287
> d_instantiate+0x5e/0xa0 fs/dcache.c:1870
> shmem_mknod+0x189/0x1f0 mm/shmem.c:2812
> vfs_mknod+0x447/0x800 fs/namei.c:3719
> handle_create+0x1ff/0x7c0 drivers/base/devtmpfs.c:211
> handle drivers/base/devtmpfs.c:374 [inline]
> devtmpfsd+0x27f/0x4c0 drivers/base/devtmpfs.c:400
> kthread+0x35a/0x420 kernel/kthread.c:246
> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
>
> -> #1 (&isp->smk_lock){+.+.}:
> __mutex_lock_common kernel/locking/mutex.c:925 [inline]
> __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073
> mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
> smack_d_instantiate+0x130/0xea0 security/smack/smack_lsm.c:3369
> security_d_instantiate+0x5c/0xf0 security/security.c:1287
... while here the same function gets called from ext4 which will have
PF_MEMALLOC_NOFS set so fs reclaim won't happen. Lockdep transfers the
locking dependency through isp->smk_lock as it is not clever enough to know
that this lock in shmfs case is different from this lock in ext4 case -
they are in the same locking class.
So what Smack needs to do to prevent these false positives is to set
locking class of its smk_lock to be different for different filesystem
types. We do the same for other inode-related locks in fs/inode.c:
inode_init_always() - see the lockdep_set_class calls there - so Smack
needs to do something similar.
> d_instantiate_new+0x7e/0x160 fs/dcache.c:1889
> ext4_add_nondir+0x81/0x90 fs/ext4/namei.c:2415
> ext4_symlink+0x761/0x1170 fs/ext4/namei.c:3162
> vfs_symlink+0x37a/0x5d0 fs/namei.c:4127
> do_symlinkat+0x242/0x2d0 fs/namei.c:4154
> __do_sys_symlink fs/namei.c:4173 [inline]
> __se_sys_symlink fs/namei.c:4171 [inline]
> __x64_sys_symlink+0x59/0x80 fs/namei.c:4171
> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 3+ messages in thread
* possible deadlock in start_this_handle
@ 2018-09-07 9:38 ` Jan Kara
0 siblings, 0 replies; 3+ messages in thread
From: Jan Kara @ 2018-09-07 9:38 UTC (permalink / raw)
To: linux-security-module
On Fri 07-09-18 01:38:03, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: ca16eb342ebe Merge tag 'for-linus-20180906' of git://git.k..
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=129e80ae400000
> kernel config: https://syzkaller.appspot.com/x/.config?x=6c9564cd177daf0c
> dashboard link: https://syzkaller.appspot.com/bug?extid=fe49aec75e221f9b093e
> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+fe49aec75e221f9b093e at syzkaller.appspotmail.com
>
So this looks like a false positive due to Michal's memalloc_nofs_save()
work and lockdep not being clever enough. And it actually nicely shows how
Michal's work prevents real deadlock possibilities.
> ======================================================
> WARNING: possible circular locking dependency detected
> 4.19.0-rc2+ #2 Not tainted
> ------------------------------------------------------
> kswapd0/1430 is trying to acquire lock:
> 0000000085a9412e (jbd2_handle){++++}, at: start_this_handle+0x589/0x1260
> fs/jbd2/transaction.c:383
>
> but task is already holding lock:
> 00000000af99a839 (fs_reclaim){+.+.}, at: __page_frag_cache_refill
> mm/page_alloc.c:4476 [inline]
> 00000000af99a839 (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x0/0x30
> mm/page_alloc.c:4505
So lockdep is complaining about kswapd starting a transaction during fs
reclaim. It should be OK to do so so let's see why lockdep thinks starting
a transaction in fs reclaim is not good.
> the existing dependency chain (in reverse order) is:
>
> -> #2 (fs_reclaim){+.+.}:
> __fs_reclaim_acquire mm/page_alloc.c:3728 [inline]
> fs_reclaim_acquire.part.98+0x24/0x30 mm/page_alloc.c:3739
> fs_reclaim_acquire+0x14/0x20 mm/page_alloc.c:3740
> slab_pre_alloc_hook mm/slab.h:418 [inline]
> slab_alloc mm/slab.c:3378 [inline]
> kmem_cache_alloc_trace+0x2d/0x730 mm/slab.c:3618
Here smack is doing GFP_KERNEL allocation. In this case it gets called from
shmfs which is OK with doing fs reclaim... <see below>
> kmalloc include/linux/slab.h:513 [inline]
> kzalloc include/linux/slab.h:707 [inline]
> smk_fetch.part.24+0x5a/0xf0 security/smack/smack_lsm.c:273
> smk_fetch security/smack/smack_lsm.c:3548 [inline]
> smack_d_instantiate+0x946/0xea0 security/smack/smack_lsm.c:3502
> security_d_instantiate+0x5c/0xf0 security/security.c:1287
> d_instantiate+0x5e/0xa0 fs/dcache.c:1870
> shmem_mknod+0x189/0x1f0 mm/shmem.c:2812
> vfs_mknod+0x447/0x800 fs/namei.c:3719
> handle_create+0x1ff/0x7c0 drivers/base/devtmpfs.c:211
> handle drivers/base/devtmpfs.c:374 [inline]
> devtmpfsd+0x27f/0x4c0 drivers/base/devtmpfs.c:400
> kthread+0x35a/0x420 kernel/kthread.c:246
> ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413
>
> -> #1 (&isp->smk_lock){+.+.}:
> __mutex_lock_common kernel/locking/mutex.c:925 [inline]
> __mutex_lock+0x171/0x1700 kernel/locking/mutex.c:1073
> mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1088
> smack_d_instantiate+0x130/0xea0 security/smack/smack_lsm.c:3369
> security_d_instantiate+0x5c/0xf0 security/security.c:1287
... while here the same function gets called from ext4 which will have
PF_MEMALLOC_NOFS set so fs reclaim won't happen. Lockdep transfers the
locking dependency through isp->smk_lock as it is not clever enough to know
that this lock in shmfs case is different from this lock in ext4 case -
they are in the same locking class.
So what Smack needs to do to prevent these false positives is to set
locking class of its smk_lock to be different for different filesystem
types. We do the same for other inode-related locks in fs/inode.c:
inode_init_always() - see the lockdep_set_class calls there - so Smack
needs to do something similar.
> d_instantiate_new+0x7e/0x160 fs/dcache.c:1889
> ext4_add_nondir+0x81/0x90 fs/ext4/namei.c:2415
> ext4_symlink+0x761/0x1170 fs/ext4/namei.c:3162
> vfs_symlink+0x37a/0x5d0 fs/namei.c:4127
> do_symlinkat+0x242/0x2d0 fs/namei.c:4154
> __do_sys_symlink fs/namei.c:4173 [inline]
> __se_sys_symlink fs/namei.c:4171 [inline]
> __x64_sys_symlink+0x59/0x80 fs/namei.c:4171
> do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2018-09-07 9:38 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2018-09-07 8:38 possible deadlock in start_this_handle syzbot
2018-09-07 9:38 ` Jan Kara
2018-09-07 9:38 ` Jan Kara
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