| Title | Replies (including bot) | Last reply |
|---|---|---|
| [syzbot] Monthly exfat report (Dec 2024) | 0 (1) | 2024/12/07 16:12 |
| [syzbot] [exfat?] possible deadlock in __generic_file_fsync (2) | 0 (1) | 2024/11/03 19:56 |
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| Title | Replies (including bot) | Last reply |
|---|---|---|
| [syzbot] Monthly exfat report (Dec 2024) | 0 (1) | 2024/12/07 16:12 |
| [syzbot] [exfat?] possible deadlock in __generic_file_fsync (2) | 0 (1) | 2024/11/03 19:56 |
| Kernel | Title | Repro | Cause bisect | Fix bisect | Count | Last | Reported | Patched | Status |
|---|---|---|---|---|---|---|---|---|---|
| linux-4.19 | possible deadlock in __generic_file_fsync ext4 btrfs fat | C | 577 | 657d | 2005d | 0/1 | upstream: reported C repro on 2019/06/13 18:12 | ||
| linux-4.14 | possible deadlock in __generic_file_fsync ext4 fat | syz | error | 171 | 662d | 1999d | 0/1 | upstream: reported syz repro on 2019/06/19 20:20 | |
| upstream | possible deadlock in __generic_file_fsync ext4 | C | done | unreliable | 80 | 2105d | 2245d | 0/28 | auto-obsoleted due to no activity on 2022/09/04 03:10 |
| android-414 | possible deadlock in __generic_file_fsync | syz | 262 | 1833d | 2068d | 0/1 | public: reported syz repro on 2019/04/12 00:01 |
======================================================
WARNING: possible circular locking dependency detected
6.12.0-syzkaller-11930-g0e287d31b62b #0 Not tainted
------------------------------------------------------
syz.3.565/7542 is trying to acquire lock:
ffff88805a15c7a0 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: inode_lock include/linux/fs.h:818 [inline]
ffff88805a15c7a0 (&sb->s_type->i_mutex_key#24){++++}-{4:4}, at: __generic_file_fsync+0xb0/0x1f0 fs/libfs.c:1536
but task is already holding lock:
ffff8880259e9e00 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: loop_set_status+0x1d9/0x700 drivers/block/loop.c:1267
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&q->q_usage_counter(io)#17){++++}-{0:0}:
bio_queue_enter block/blk.h:75 [inline]
blk_mq_submit_bio+0x1fb6/0x24c0 block/blk-mq.c:3092
__submit_bio+0x384/0x540 block/blk-core.c:629
__submit_bio_noacct_mq block/blk-core.c:710 [inline]
submit_bio_noacct_nocheck+0x698/0xd70 block/blk-core.c:739
submit_bio_noacct+0x93a/0x1e20 block/blk-core.c:868
submit_bh fs/buffer.c:2819 [inline]
__bread_slow fs/buffer.c:1264 [inline]
__bread_gfp+0x189/0x340 fs/buffer.c:1488
sb_bread include/linux/buffer_head.h:346 [inline]
fat_ent_bread+0x16b/0x330 fs/fat/fatent.c:109
fat_ent_read_block fs/fat/fatent.c:445 [inline]
fat_alloc_clusters+0x58b/0xf80 fs/fat/fatent.c:493
fat_add_new_entries+0x230/0xf50 fs/fat/dir.c:1230
fat_add_entries+0xc34/0x1530 fs/fat/dir.c:1388
vfat_add_entry+0x298d/0x2fe0 fs/fat/namei_vfat.c:677
vfat_create+0x15f/0x2c0 fs/fat/namei_vfat.c:771
lookup_open.isra.0+0x1177/0x14c0 fs/namei.c:3649
open_last_lookups fs/namei.c:3748 [inline]
path_openat+0x904/0x2d60 fs/namei.c:3984
do_filp_open+0x20c/0x470 fs/namei.c:4014
do_sys_openat2+0x17a/0x1e0 fs/open.c:1402
do_sys_open fs/open.c:1417 [inline]
__do_sys_openat fs/open.c:1433 [inline]
__se_sys_openat fs/open.c:1428 [inline]
__x64_sys_openat+0x175/0x210 fs/open.c:1428
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (&sbi->fat_lock){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:585 [inline]
__mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735
lock_fat fs/fat/fatent.c:281 [inline]
fat_alloc_clusters+0x1b9/0xf80 fs/fat/fatent.c:477
fat_add_cluster+0x79/0x100 fs/fat/inode.c:107
__fat_get_block fs/fat/inode.c:154 [inline]
fat_get_block+0x38e/0xaf0 fs/fat/inode.c:189
__block_write_begin_int+0x4fe/0x16e0 fs/buffer.c:2116
block_write_begin+0x9a/0x1d0 fs/buffer.c:2226
cont_write_begin+0x61d/0x950 fs/buffer.c:2577
fat_write_begin+0x66/0x150 fs/fat/inode.c:228
generic_perform_write+0x2bd/0x920 mm/filemap.c:4055
__generic_file_write_iter+0x1f7/0x240 mm/filemap.c:4156
generic_file_write_iter+0xe1/0x340 mm/filemap.c:4182
new_sync_write fs/read_write.c:586 [inline]
vfs_write+0x5b1/0x1150 fs/read_write.c:679
ksys_write+0x12b/0x250 fs/read_write.c:731
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&sb->s_type->i_mutex_key#24){++++}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
down_write+0x93/0x200 kernel/locking/rwsem.c:1577
inode_lock include/linux/fs.h:818 [inline]
__generic_file_fsync+0xb0/0x1f0 fs/libfs.c:1536
fat_file_fsync+0x70/0x210 fs/fat/file.c:191
vfs_fsync_range fs/sync.c:187 [inline]
vfs_fsync+0x12d/0x1f0 fs/sync.c:201
__loop_update_dio+0x182/0x570 drivers/block/loop.c:204
loop_set_status+0x2a4/0x700 drivers/block/loop.c:1289
loop_set_status64 drivers/block/loop.c:1398 [inline]
lo_ioctl+0x6ec/0x18b0 drivers/block/loop.c:1548
blkdev_ioctl+0x279/0x6d0 block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&sb->s_type->i_mutex_key#24 --> &sbi->fat_lock --> &q->q_usage_counter(io)#17
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&q->q_usage_counter(io)#17);
lock(&sbi->fat_lock);
lock(&q->q_usage_counter(io)#17);
lock(&sb->s_type->i_mutex_key#24);
*** DEADLOCK ***
3 locks held by syz.3.565/7542:
#0: ffff8880256acb60 (&lo->lo_mutex){+.+.}-{4:4}, at: loop_set_status+0x2a/0x700 drivers/block/loop.c:1251
#1: ffff8880259e9e00 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: loop_set_status+0x1d9/0x700 drivers/block/loop.c:1267
#2: ffff8880259e9e38 (&q->q_usage_counter(queue)){+.+.}-{0:0}, at: loop_set_status+0x1d9/0x700 drivers/block/loop.c:1267
stack backtrace:
CPU: 1 UID: 0 PID: 7542 Comm: syz.3.565 Not tainted 6.12.0-syzkaller-11930-g0e287d31b62b #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
down_write+0x93/0x200 kernel/locking/rwsem.c:1577
inode_lock include/linux/fs.h:818 [inline]
__generic_file_fsync+0xb0/0x1f0 fs/libfs.c:1536
fat_file_fsync+0x70/0x210 fs/fat/file.c:191
vfs_fsync_range fs/sync.c:187 [inline]
vfs_fsync+0x12d/0x1f0 fs/sync.c:201
__loop_update_dio+0x182/0x570 drivers/block/loop.c:204
loop_set_status+0x2a4/0x700 drivers/block/loop.c:1289
loop_set_status64 drivers/block/loop.c:1398 [inline]
lo_ioctl+0x6ec/0x18b0 drivers/block/loop.c:1548
blkdev_ioctl+0x279/0x6d0 block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:892
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e45980849
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0e466d7058 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f0e45b45fa0 RCX: 00007f0e45980849
RDX: 0000000020001300 RSI: 0000000000004c04 RDI: 0000000000000004
RBP: 00007f0e459f3986 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0e45b45fa0 R15: 00007ffee3dbe258
</TASK>
| Time | Kernel | Commit | Syzkaller | Config | Log | Report | Syz repro | C repro | VM info | Assets (help?) | Manager | Title |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 2024/12/01 00:06 | upstream | 0e287d31b62b | 68914665 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci-upstream-kasan-badwrites-root | possible deadlock in __generic_file_fsync | ||
| 2024/10/30 19:49 | linux-next | 86e3904dcdc7 | 66aeb999 | .config | console log | report | info | [disk image] [vmlinux] [kernel image] | ci-upstream-linux-next-kasan-gce-root | possible deadlock in __generic_file_fsync |