syzbot


possible deadlock in do_qc

Status: upstream: reported on 2024/04/28 01:25
Reported-by: syzbot+bdc96b32d35cce7a6064@syzkaller.appspotmail.com
First crash: 197d, last: 1d07h
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in do_qc gfs2 785 90d 218d 0/28 auto-obsoleted due to no activity on 2024/10/22 09:11
linux-5.15 possible deadlock in do_qc 376 2d01h 197d 0/3 upstream: reported on 2024/04/27 22:18

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.1.115-syzkaller #0 Not tainted
------------------------------------------------------
syz.1.2/4326 is trying to acquire lock:
ffff88807ad14ae0 (&sdp->sd_quota_mutex){+.+.}-{3:3}, at: do_qc+0xc8/0x720 fs/gfs2/quota.c:682

but task is already holding lock:
ffff88805a1f2780 (&ip->i_rw_mutex){++++}-{3:3}, at: __gfs2_iomap_alloc+0x2b7/0x2090 fs/gfs2/bmap.c:679

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&ip->i_rw_mutex){++++}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       __gfs2_iomap_get+0x178/0x1480 fs/gfs2/bmap.c:856
       gfs2_iomap_get+0xdb/0x150 fs/gfs2/bmap.c:1396
       bh_get+0x286/0x800 fs/gfs2/quota.c:385
       qdsb_get+0x209/0x3b0 fs/gfs2/quota.c:522
       gfs2_quota_hold+0x19d/0x5c0 fs/gfs2/quota.c:608
       gfs2_quota_lock+0x9f/0x450 fs/gfs2/quota.c:1076
       gfs2_quota_lock_check fs/gfs2/quota.h:50 [inline]
       alloc_dinode+0x1c9/0x580 fs/gfs2/inode.c:393
       gfs2_create_inode+0x1019/0x1c00 fs/gfs2/inode.c:711
       gfs2_atomic_open+0xe1/0x220 fs/gfs2/inode.c:1292
       atomic_open fs/namei.c:3345 [inline]
       lookup_open fs/namei.c:3453 [inline]
       open_last_lookups fs/namei.c:3550 [inline]
       path_openat+0xf4e/0x2e60 fs/namei.c:3780
       do_filp_open+0x230/0x480 fs/namei.c:3810
       do_sys_openat2+0x13b/0x4f0 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_creat fs/open.c:1412 [inline]
       __se_sys_creat fs/open.c:1406 [inline]
       __x64_sys_creat+0x11f/0x160 fs/open.c:1406
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&sdp->sd_quota_mutex){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       do_qc+0xc8/0x720 fs/gfs2/quota.c:682
       gfs2_quota_change+0x2db/0x8c0 fs/gfs2/quota.c:1295
       gfs2_alloc_blocks+0x1e50/0x28c0 fs/gfs2/rgrp.c:2494
       __gfs2_iomap_alloc+0x4f0/0x2090 fs/gfs2/bmap.c:705
       gfs2_iomap_begin_write fs/gfs2/bmap.c:1047 [inline]
       gfs2_iomap_begin+0xb40/0x1470 fs/gfs2/bmap.c:1112
       iomap_iter+0x6c8/0x1090 fs/iomap/iter.c:91
       iomap_file_buffered_write+0x2a9/0xc90 fs/iomap/buffered-io.c:846
       gfs2_file_buffered_write+0x4e3/0x870 fs/gfs2/file.c:1056
       gfs2_file_write_iter+0x415/0xe90 fs/gfs2/file.c:1157
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x857/0xbc0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&ip->i_rw_mutex);
                               lock(&sdp->sd_quota_mutex);
                               lock(&ip->i_rw_mutex);
  lock(&sdp->sd_quota_mutex);

 *** DEADLOCK ***

6 locks held by syz.1.2/4326:
 #0: ffff88802031cd68 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ba/0x360 fs/file.c:1031
 #1: ffff888058744460 (sb_writers#13){.+.+}-{0:0}, at: vfs_write+0x269/0xbc0 fs/read_write.c:580
 #2: ffff88805a1f22e8 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff88805a1f22e8 (&sb->s_type->i_mutex_key#21){+.+.}-{3:3}, at: gfs2_file_write_iter+0x347/0xe90 fs/gfs2/file.c:1114
 #3: ffff888058744650 (sb_internal#2){.+.+}-{0:0}, at: gfs2_trans_begin+0x6d/0xe0 fs/gfs2/trans.c:118
 #4: ffff88807ad15058 (&sdp->sd_log_flush_lock){.+.+}-{3:3}, at: __gfs2_trans_begin+0x558/0x940 fs/gfs2/trans.c:87
 #5: ffff88805a1f2780 (&ip->i_rw_mutex){++++}-{3:3}, at: __gfs2_iomap_alloc+0x2b7/0x2090 fs/gfs2/bmap.c:679

stack backtrace:
CPU: 1 PID: 4326 Comm: syz.1.2 Not tainted 6.1.115-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __mutex_lock_common kernel/locking/mutex.c:603 [inline]
 __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
 do_qc+0xc8/0x720 fs/gfs2/quota.c:682
 gfs2_quota_change+0x2db/0x8c0 fs/gfs2/quota.c:1295
 gfs2_alloc_blocks+0x1e50/0x28c0 fs/gfs2/rgrp.c:2494
 __gfs2_iomap_alloc+0x4f0/0x2090 fs/gfs2/bmap.c:705
 gfs2_iomap_begin_write fs/gfs2/bmap.c:1047 [inline]
 gfs2_iomap_begin+0xb40/0x1470 fs/gfs2/bmap.c:1112
 iomap_iter+0x6c8/0x1090 fs/iomap/iter.c:91
 iomap_file_buffered_write+0x2a9/0xc90 fs/iomap/buffered-io.c:846
 gfs2_file_buffered_write+0x4e3/0x870 fs/gfs2/file.c:1056
 gfs2_file_write_iter+0x415/0xe90 fs/gfs2/file.c:1157
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x857/0xbc0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f736477e719
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:00007f7365603038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7364935f80 RCX: 00007f736477e719
RDX: 0000000000000378 RSI: 0000000020001640 RDI: 0000000000000004
RBP: 00007f73647f132e R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f7364935f80 R15: 00007fff4c22dec8
 </TASK>

Crashes (183):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/01 15:32 linux-6.1.y 7c15117f9468 96eb609f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/10/23 12:07 linux-6.1.y 7ec6f9fa3d97 15fa2979 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/10/18 05:46 linux-6.1.y 54d90d17e8ce 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/10/18 04:37 linux-6.1.y 54d90d17e8ce 666f77ed .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/10/16 09:52 linux-6.1.y aa4cd140bba5 bde2d81c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/10/07 14:22 linux-6.1.y aa4cd140bba5 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/10/04 12:59 linux-6.1.y aa4cd140bba5 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/10/04 03:51 linux-6.1.y aa4cd140bba5 d7906eff .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/09/15 11:17 linux-6.1.y 5f55cad62cc9 08d8a733 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/07/17 15:51 linux-6.1.y cac15753b8ce 215bec2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/07/08 01:26 linux-6.1.y 7753af06eebf 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/07/07 11:12 linux-6.1.y 7753af06eebf 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/07/06 12:30 linux-6.1.y 7753af06eebf 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/07/06 05:22 linux-6.1.y 7753af06eebf 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/07/06 04:06 linux-6.1.y 7753af06eebf 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/07/05 00:19 linux-6.1.y 99e6a620de00 3f2748a3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/07/02 00:22 linux-6.1.y 99e6a620de00 b294e901 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/06/14 06:17 linux-6.1.y ae9f2a70d69e a9616ff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in do_qc
2024/11/10 06:35 linux-6.1.y d7039b844a1c 6b856513 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/11/07 09:33 linux-6.1.y 7c15117f9468 df3dc63b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/11/04 21:37 linux-6.1.y 7c15117f9468 509da429 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/11/03 15:14 linux-6.1.y 7c15117f9468 f00eed24 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/10/31 21:39 linux-6.1.y 7ec6f9fa3d97 96eb609f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/10/28 02:28 linux-6.1.y 7ec6f9fa3d97 65e8686b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/10/28 01:00 linux-6.1.y 7ec6f9fa3d97 65e8686b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/10/27 14:53 linux-6.1.y 7ec6f9fa3d97 65e8686b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/10/25 22:12 linux-6.1.y 7ec6f9fa3d97 045e728d .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/09/28 23:33 linux-6.1.y e526b12bf916 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/09/21 23:16 linux-6.1.y e526b12bf916 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/09/09 08:48 linux-6.1.y 5ca5b389fddf 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/09/08 03:51 linux-6.1.y 699506173494 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/09/08 01:00 linux-6.1.y 699506173494 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/08/27 15:51 linux-6.1.y ee5e09825b81 9aee4e0b .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/08/16 23:52 linux-6.1.y 117ac406ba90 e1c76ab2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/08/16 22:05 linux-6.1.y 117ac406ba90 e1c76ab2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/08/15 20:35 linux-6.1.y 117ac406ba90 e4bacdaf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/08/03 18:39 linux-6.1.y 48d525b0e463 1786a2a8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/07/08 08:15 linux-6.1.y 7753af06eebf 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/07/06 11:19 linux-6.1.y 7753af06eebf 2a40360c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/07/03 02:53 linux-6.1.y 99e6a620de00 07f0a0a0 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/06/22 23:28 linux-6.1.y eb44d83053d6 edc5149a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/06/18 21:23 linux-6.1.y eb44d83053d6 639d6cdf .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/06/14 04:23 linux-6.1.y ae9f2a70d69e a9616ff5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/06/10 10:07 linux-6.1.y 88690811da69 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/06/10 09:06 linux-6.1.y 88690811da69 82c05ab8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
2024/04/28 01:25 linux-6.1.y f2295faba5e8 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in do_qc
* Struck through repros no longer work on HEAD.