syzbot


possible deadlock in iterate_dir

Status: auto-obsoleted due to no activity on 2023/10/27 20:39
Reported-by: syzbot+fa6c8166fd705febe592@syzkaller.appspotmail.com
First crash: 496d, last: 490d
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 possible deadlock in iterate_dir (3) origin:upstream C error 6 44d 232d 0/3 upstream: reported C repro on 2024/04/03 07:56
linux-6.1 possible deadlock in iterate_dir (2) 2 210d 236d 0/3 auto-obsoleted due to no activity on 2024/08/02 17:42
linux-4.14 possible deadlock in iterate_dir ubifs C 11375 625d 1620d 0/1 upstream: reported C repro on 2020/06/15 06:16
linux-5.15 possible deadlock in iterate_dir (2) 2 358d 450d 0/3 auto-obsoleted due to no activity on 2024/03/08 13:21
linux-4.19 possible deadlock in iterate_dir 1 1792d 1792d 0/1 auto-closed as invalid on 2020/04/24 15:06
upstream possible deadlock in iterate_dir reiserfs 23 455d 698d 0/28 auto-obsoleted due to no activity on 2023/12/01 22:38
linux-5.15 possible deadlock in iterate_dir 1 605d 605d 0/3 auto-obsoleted due to no activity on 2023/07/25 13:55

Sample crash report:
REISERFS warning (device loop1): vs-13060 reiserfs_update_sd_size: stat data of object [1 2 0x0 SD] (nlink == 4) not found (pos 2)
REISERFS (device loop1): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.1.39-syzkaller #0 Not tainted
------------------------------------------------------
syz-executor.1/12142 is trying to acquire lock:
ffff0000dd5f2090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27

but task is already holding lock:
ffff0000d82c0460 (sb_writers#24){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2535 [inline]
ffff0000d82c0460 (sb_writers#24){.+.+}-{0:0}, at: iterate_dir+0x400/0x4e4 fs/readdir.c:70

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (sb_writers#24){.+.+}-{0:0}:
       percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
       __sb_start_write include/linux/fs.h:1832 [inline]
       sb_start_write+0x7c/0x308 include/linux/fs.h:1907
       mnt_want_write_file+0x64/0x1e8 fs/namespace.c:437
       reiserfs_ioctl+0x184/0x454 fs/reiserfs/ioctl.c:103
       vfs_ioctl fs/ioctl.c:51 [inline]
       __do_sys_ioctl fs/ioctl.c:870 [inline]
       __se_sys_ioctl fs/ioctl.c:856 [inline]
       __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:856
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

-> #0 (&sbi->lock){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3098 [inline]
       check_prevs_add kernel/locking/lockdep.c:3217 [inline]
       validate_chain kernel/locking/lockdep.c:3832 [inline]
       __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
       lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669
       __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
       __mutex_lock kernel/locking/mutex.c:747 [inline]
       mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
       reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
       reiserfs_dirty_inode+0xe4/0x204 fs/reiserfs/super.c:704
       __mark_inode_dirty+0x2f8/0x1354 fs/fs-writeback.c:2411
       generic_update_time fs/inode.c:1901 [inline]
       inode_update_time fs/inode.c:1914 [inline]
       touch_atime+0x5f0/0x8ec fs/inode.c:1986
       file_accessed include/linux/fs.h:2535 [inline]
       iterate_dir+0x400/0x4e4 fs/readdir.c:70
       __do_sys_getdents64 fs/readdir.c:369 [inline]
       __se_sys_getdents64 fs/readdir.c:354 [inline]
       __arm64_sys_getdents64+0x1c4/0x4a0 fs/readdir.c:354
       __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
       invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
       el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
       do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
       el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
       el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
       el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sb_writers#24);
                               lock(&sbi->lock);
                               lock(sb_writers#24);
  lock(&sbi->lock);

 *** DEADLOCK ***

3 locks held by syz-executor.1/12142:
 #0: ffff0000df10c0e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xd8/0x104 fs/file.c:1047
 #1: ffff000104109d60 (&type->i_mutex_dir_key#18){++++}-{3:3}, at: iterate_dir+0x108/0x4e4 fs/readdir.c:55
 #2: ffff0000d82c0460 (sb_writers#24){.+.+}-{0:0}, at: file_accessed include/linux/fs.h:2535 [inline]
 #2: ffff0000d82c0460 (sb_writers#24){.+.+}-{0:0}, at: iterate_dir+0x400/0x4e4 fs/readdir.c:70

stack backtrace:
CPU: 0 PID: 12142 Comm: syz-executor.1 Not tainted 6.1.39-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Call trace:
 dump_backtrace+0x1c8/0x1f4 arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x108/0x170 lib/dump_stack.c:106
 dump_stack+0x1c/0x58 lib/dump_stack.c:113
 print_circular_bug+0x150/0x1b8 kernel/locking/lockdep.c:2056
 check_noncircular+0x2cc/0x378 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 kernel/locking/lockdep.c:3832 [inline]
 __lock_acquire+0x3338/0x764c kernel/locking/lockdep.c:5056
 lock_acquire+0x26c/0x7cc kernel/locking/lockdep.c:5669
 __mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:603
 __mutex_lock kernel/locking/mutex.c:747 [inline]
 mutex_lock_nested+0x38/0x44 kernel/locking/mutex.c:799
 reiserfs_write_lock+0x7c/0xe8 fs/reiserfs/lock.c:27
 reiserfs_dirty_inode+0xe4/0x204 fs/reiserfs/super.c:704
 __mark_inode_dirty+0x2f8/0x1354 fs/fs-writeback.c:2411
 generic_update_time fs/inode.c:1901 [inline]
 inode_update_time fs/inode.c:1914 [inline]
 touch_atime+0x5f0/0x8ec fs/inode.c:1986
 file_accessed include/linux/fs.h:2535 [inline]
 iterate_dir+0x400/0x4e4 fs/readdir.c:70
 __do_sys_getdents64 fs/readdir.c:369 [inline]
 __se_sys_getdents64 fs/readdir.c:354 [inline]
 __arm64_sys_getdents64+0x1c4/0x4a0 fs/readdir.c:354
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x64/0x218 arch/arm64/kernel/syscall.c:206
 el0_svc+0x58/0x168 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:581
REISERFS warning (device loop1): vs-13060 reiserfs_update_sd_size: stat data of object [1 2 0x0 SD] (nlink == 4) not found (pos 2)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/19 20:38 linux-6.1.y a456e1743881 4547cdf9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in iterate_dir
2023/07/14 05:21 linux-6.1.y 61fd484b2cf6 d624500f .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan-arm64 possible deadlock in iterate_dir
* Struck through repros no longer work on HEAD.