syzbot


possible deadlock in f2fs_getxattr

Status: fixed on 2023/10/24 17:33
Bug presence: origin:upstream
Labels: missing-backport
[Documentation on labels]
Reported-by: syzbot+2f4b985b687de640df5b@syzkaller.appspotmail.com
Fix commit: 980b592c6087 f2fs: avoid false alarm of circular locking
First crash: 498d, last: 441d
Fix bisection: fixed by (bisect log) :
commit 980b592c60874d9b8bca5663549edc73acd42946
Author: Jaegeuk Kim <jaegeuk@kernel.org>
Date: Fri Aug 18 18:34:32 2023 +0000

  f2fs: avoid false alarm of circular locking

  
Bug presence (3)
Date Name Commit Repro Result
2023/09/13 linux-6.1.y (ToT) 09045dae0d90 C [report] possible deadlock in f2fs_getxattr
2023/07/29 upstream (ToT) ffabf7c73176 C [report] possible deadlock in f2fs_getxattr
2023/09/13 upstream (ToT) 3669558bdf35 C Didn't crash
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in f2fs_getxattr f2fs C done 4570 434d 515d 23/28 fixed on 2023/10/12 12:47

Sample crash report:
loop0: detected capacity change from 0 to 40427
F2FS-fs (loop0): Invalid log_blocksize (268), supports only 12
F2FS-fs (loop0): Can't find valid F2FS filesystem in 1th superblock
F2FS-fs (loop0): Found nat_bits in checkpoint
F2FS-fs (loop0): Try to recover 1th superblock, ret: 0
F2FS-fs (loop0): Mounted with checkpoint version = 48b305e5
======================================================
WARNING: possible circular locking dependency detected
6.1.42-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor272/3538 is trying to acquire lock:
ffff8880744510a8 (&fi->i_xattr_sem){.+.+}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2154 [inline]
ffff8880744510a8 (&fi->i_xattr_sem){.+.+}-{3:3}, at: f2fs_getxattr+0xb4/0x1460 fs/f2fs/xattr.c:531

but task is already holding lock:
ffff888075fd16f8 (&fi->i_sem){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2179 [inline]
ffff888075fd16f8 (&fi->i_sem){+.+.}-{3:3}, at: f2fs_do_tmpfile+0x21/0x160 fs/f2fs/dir.c:869

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&fi->i_sem){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       f2fs_down_write fs/f2fs/f2fs.h:2179 [inline]
       f2fs_add_inline_entry+0x3a4/0x760 fs/f2fs/inline.c:645
       f2fs_add_dentry+0xb6/0x1e0 fs/f2fs/dir.c:815
       f2fs_do_add_link+0x21a/0x340 fs/f2fs/dir.c:858
       f2fs_add_link fs/f2fs/f2fs.h:3530 [inline]
       f2fs_create+0x749/0xa10 fs/f2fs/namei.c:367
       lookup_open fs/namei.c:3413 [inline]
       open_last_lookups fs/namei.c:3481 [inline]
       path_openat+0x12f1/0x2e60 fs/namei.c:3711
       do_filp_open+0x230/0x480 fs/namei.c:3741
       do_sys_openat2+0x13b/0x500 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_creat fs/open.c:1410 [inline]
       __se_sys_creat fs/open.c:1404 [inline]
       __x64_sys_creat+0x11f/0x160 fs/open.c:1404
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #0 (&fi->i_xattr_sem){.+.+}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3098 [inline]
       check_prevs_add kernel/locking/lockdep.c:3217 [inline]
       validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
       down_read+0x43/0x2e0 kernel/locking/rwsem.c:1520
       f2fs_down_read fs/f2fs/f2fs.h:2154 [inline]
       f2fs_getxattr+0xb4/0x1460 fs/f2fs/xattr.c:531
       __f2fs_get_acl+0x52/0x8a0 fs/f2fs/acl.c:179
       f2fs_acl_create fs/f2fs/acl.c:375 [inline]
       f2fs_init_acl+0xd3/0x960 fs/f2fs/acl.c:418
       f2fs_init_inode_metadata+0xaa0/0x11d0 fs/f2fs/dir.c:587
       f2fs_do_tmpfile+0x30/0x160 fs/f2fs/dir.c:870
       __f2fs_tmpfile+0x1f9/0x380 fs/f2fs/namei.c:874
       f2fs_ioc_start_atomic_write fs/f2fs/file.c:2107 [inline]
       __f2fs_ioctl+0x9a02/0xbf70 fs/f2fs/file.c:4171
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:50 [inline]
       do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
       entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&fi->i_sem);
                               lock(&fi->i_xattr_sem);
                               lock(&fi->i_sem);
  lock(&fi->i_xattr_sem);

 *** DEADLOCK ***

5 locks held by syz-executor272/3538:
 #0: ffff888076186460 (sb_writers#9){.+.+}-{0:0}, at: mnt_want_write_file+0x5a/0x1f0 fs/namespace.c:437
 #1: ffff888075fd0a38 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:756 [inline]
 #1: ffff888075fd0a38 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: f2fs_ioc_start_atomic_write fs/f2fs/file.c:2068 [inline]
 #1: ffff888075fd0a38 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}, at: __f2fs_ioctl+0x4142/0xbf70 fs/f2fs/file.c:4171
 #2: ffff888075fd1010 (&fi->i_gc_rwsem[WRITE]){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2179 [inline]
 #2: ffff888075fd1010 (&fi->i_gc_rwsem[WRITE]){+.+.}-{3:3}, at: f2fs_ioc_start_atomic_write fs/f2fs/file.c:2082 [inline]
 #2: ffff888075fd1010 (&fi->i_gc_rwsem[WRITE]){+.+.}-{3:3}, at: __f2fs_ioctl+0x5457/0xbf70 fs/f2fs/file.c:4171
 #3: ffff88807d1803b0 (&sbi->cp_rwsem){++++}-{3:3}, at: f2fs_down_read fs/f2fs/f2fs.h:2154 [inline]
 #3: ffff88807d1803b0 (&sbi->cp_rwsem){++++}-{3:3}, at: f2fs_lock_op fs/f2fs/f2fs.h:2197 [inline]
 #3: ffff88807d1803b0 (&sbi->cp_rwsem){++++}-{3:3}, at: __f2fs_tmpfile+0x1ce/0x380 fs/f2fs/namei.c:869
 #4: ffff888075fd16f8 (&fi->i_sem){+.+.}-{3:3}, at: f2fs_down_write fs/f2fs/f2fs.h:2179 [inline]
 #4: ffff888075fd16f8 (&fi->i_sem){+.+.}-{3:3}, at: f2fs_do_tmpfile+0x21/0x160 fs/f2fs/dir.c:869

stack backtrace:
CPU: 1 PID: 3538 Comm: syz-executor272 Not tainted 6.1.42-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2023
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:2178
 check_prev_add kernel/locking/lockdep.c:3098 [inline]
 check_prevs_add kernel/locking/lockdep.c:3217 [inline]
 validate_chain+0x1667/0x58e0 kernel/locking/lockdep.c:3832
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5056
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5669
 down_read+0x43/0x2e0 kernel/locking/rwsem.c:1520
 f2fs_down_read fs/f2fs/f2fs.h:2154 [inline]
 f2fs_getxattr+0xb4/0x1460 fs/f2fs/xattr.c:531
 __f2fs_get_acl+0x52/0x8a0 fs/f2fs/acl.c:179
 f2fs_acl_create fs/f2fs/acl.c:375 [inline]
 f2fs_init_acl+0xd3/0x960 fs/f2fs/acl.c:418
 f2fs_init_inode_metadata+0xaa0/0x11d0 fs/f2fs/dir.c:587
 f2fs_do_tmpfile+0x30/0x160 fs/f2fs/dir.c:870
 __f2fs_tmpfile+0x1f9/0x380 fs/f2fs/namei.c:874
 f2fs_ioc_start_atomic_write fs/f2fs/file.c:2107 [inline]
 __f2fs_ioctl+0x9a02/0xbf70 fs/f2fs/file.c:4171
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fa316d78639
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 17 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 

Crashes (1043):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/29 10:12 linux-6.1.y d2a6dc4eaf6d 92476829 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/08/11 08:47 linux-6.1.y 0a4a7855302d da3c3ef8 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/19 03:15 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/18 21:19 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/18 16:56 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/18 14:14 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/18 10:59 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/18 08:30 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/18 06:45 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/17 15:30 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/17 08:25 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/17 00:27 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/16 23:24 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/16 20:12 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/16 15:05 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/16 11:36 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/16 05:49 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/16 03:59 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/16 02:11 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/15 21:43 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/15 05:41 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/14 12:18 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/14 10:27 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/14 04:45 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/13 19:19 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/13 17:21 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/13 16:12 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/13 15:00 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/13 13:33 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in f2fs_getxattr
2023/09/19 07:09 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/19 06:00 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/19 02:08 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/18 23:48 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/18 22:26 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/18 19:59 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/18 09:56 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/17 18:53 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/17 07:05 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/17 05:19 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/17 03:47 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/17 02:00 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/15 20:42 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/15 16:53 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/15 07:33 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/14 23:37 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/14 04:44 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/09/13 12:25 linux-6.1.y 09045dae0d90 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
2023/07/23 15:35 linux-6.1.y 75389113731b 27cbe77f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in f2fs_getxattr
* Struck through repros no longer work on HEAD.