syzbot


possible deadlock in jfs_mount_rw

Status: upstream: reported on 2024/04/23 22:47
Subsystems: jfs
[Documentation on labels]
Reported-by: syzbot+1bd2671092cc9e4d4fef@syzkaller.appspotmail.com
First crash: 14d, last: 14d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [jfs?] possible deadlock in jfs_mount_rw 0 (1) 2024/04/23 22:47

Sample crash report:
 ... Log Wrap ... Log Wrap ... Log Wrap ...
 ... Log Wrap ... Log Wrap ... Log Wrap ...
======================================================
WARNING: possible circular locking dependency detected
6.9.0-rc4-syzkaller-00164-gdbe0a7be2838 #0 Not tainted
------------------------------------------------------
syz-executor.2/8572 is trying to acquire lock:
ffffffff8d9373c0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:312 [inline]
ffffffff8d9373c0 (fs_reclaim){+.+.}-{0:0}, at: prepare_alloc_pages.constprop.0+0x155/0x560 mm/page_alloc.c:4346

but task is already holding lock:
ffff8880282e2638 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: jfs_mount_rw+0x1eb/0x700 fs/jfs/jfs_mount.c:238

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&jfs_ip->rdwrlock/1){++++}-{3:3}:
       down_read_nested+0x9e/0x330 kernel/locking/rwsem.c:1651
       diAlloc+0x3ea/0x1a70 fs/jfs/jfs_imap.c:1385
       ialloc+0x84/0x9e0 fs/jfs/jfs_inode.c:56
       jfs_symlink+0x277/0x1140 fs/jfs/namei.c:917
       vfs_symlink fs/namei.c:4481 [inline]
       vfs_symlink+0x3e8/0x630 fs/namei.c:4465
       do_symlinkat+0x263/0x310 fs/namei.c:4507
       __do_sys_symlinkat fs/namei.c:4523 [inline]
       __se_sys_symlinkat fs/namei.c:4520 [inline]
       __ia32_sys_symlinkat+0x97/0xc0 fs/namei.c:4520
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:321
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #1 (&(imap->im_aglock[index])){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
       diFree+0x2ff/0x2770 fs/jfs/jfs_imap.c:886
       jfs_evict_inode+0x3d4/0x4b0 fs/jfs/inode.c:156
       evict+0x2ed/0x6c0 fs/inode.c:667
       iput_final fs/inode.c:1741 [inline]
       iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
       iput+0x5c/0x80 fs/inode.c:1757
       dentry_unlink_inode+0x295/0x440 fs/dcache.c:400
       __dentry_kill+0x1d0/0x600 fs/dcache.c:603
       shrink_kill fs/dcache.c:1048 [inline]
       shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075
       prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156
       super_cache_scan+0x32a/0x550 fs/super.c:221
       do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
       shrink_slab_memcg mm/shrinker.c:548 [inline]
       shrink_slab+0xa87/0x1310 mm/shrinker.c:626
       shrink_one+0x493/0x7c0 mm/vmscan.c:4774
       shrink_many mm/vmscan.c:4835 [inline]
       lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935
       shrink_node mm/vmscan.c:5894 [inline]
       kswapd_shrink_node mm/vmscan.c:6704 [inline]
       balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895
       kswapd+0x5ea/0xbf0 mm/vmscan.c:7164
       kthread+0x2c1/0x3a0 kernel/kthread.c:388
       ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
       ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 (fs_reclaim){+.+.}-{0:0}:
       check_prev_add kernel/locking/lockdep.c:3134 [inline]
       check_prevs_add kernel/locking/lockdep.c:3253 [inline]
       validate_chain kernel/locking/lockdep.c:3869 [inline]
       __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
       lock_acquire kernel/locking/lockdep.c:5754 [inline]
       lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
       __fs_reclaim_acquire mm/page_alloc.c:3698 [inline]
       fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3712
       might_alloc include/linux/sched/mm.h:312 [inline]
       prepare_alloc_pages.constprop.0+0x155/0x560 mm/page_alloc.c:4346
       __alloc_pages+0x194/0x2460 mm/page_alloc.c:4564
       __alloc_pages_node include/linux/gfp.h:238 [inline]
       alloc_pages_node include/linux/gfp.h:261 [inline]
       __kmalloc_large_node+0x7f/0x1a0 mm/slub.c:3911
       kmalloc_large+0x1c/0x70 mm/slub.c:3928
       kmalloc include/linux/slab.h:625 [inline]
       diMount+0x29/0x8d0 fs/jfs/jfs_imap.c:105
       jfs_mount_rw+0x238/0x700 fs/jfs/jfs_mount.c:240
       jfs_remount+0x51f/0x650 fs/jfs/super.c:454
       legacy_reconfigure+0x119/0x180 fs/fs_context.c:685
       reconfigure_super+0x44f/0xb20 fs/super.c:1071
       vfs_cmd_reconfigure fs/fsopen.c:267 [inline]
       vfs_fsconfig_locked fs/fsopen.c:296 [inline]
       __do_sys_fsconfig+0x991/0xb90 fs/fsopen.c:476
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:321
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

other info that might help us debug this:

Chain exists of:
  fs_reclaim --> &(imap->im_aglock[index]) --> &jfs_ip->rdwrlock/1

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&jfs_ip->rdwrlock/1);
                               lock(&(imap->im_aglock[index]));
                               lock(&jfs_ip->rdwrlock/1);
  lock(fs_reclaim);

 *** DEADLOCK ***

3 locks held by syz-executor.2/8572:
 #0: ffff8880264b1c70 (&fc->uapi_mutex){+.+.}-{3:3}, at: __do_sys_fsconfig+0x7d4/0xb90 fs/fsopen.c:474
 #1: ffff888015ff40e0 (&type->s_umount_key#67){++++}-{3:3}, at: vfs_cmd_reconfigure fs/fsopen.c:266 [inline]
 #1: ffff888015ff40e0 (&type->s_umount_key#67){++++}-{3:3}, at: vfs_fsconfig_locked fs/fsopen.c:296 [inline]
 #1: ffff888015ff40e0 (&type->s_umount_key#67){++++}-{3:3}, at: __do_sys_fsconfig+0x987/0xb90 fs/fsopen.c:476
 #2: ffff8880282e2638 (&jfs_ip->rdwrlock/1){++++}-{3:3}, at: jfs_mount_rw+0x1eb/0x700 fs/jfs/jfs_mount.c:238

stack backtrace:
CPU: 3 PID: 8572 Comm: syz-executor.2 Not tainted 6.9.0-rc4-syzkaller-00164-gdbe0a7be2838 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187
 check_prev_add kernel/locking/lockdep.c:3134 [inline]
 check_prevs_add kernel/locking/lockdep.c:3253 [inline]
 validate_chain kernel/locking/lockdep.c:3869 [inline]
 __lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
 lock_acquire kernel/locking/lockdep.c:5754 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
 __fs_reclaim_acquire mm/page_alloc.c:3698 [inline]
 fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3712
 might_alloc include/linux/sched/mm.h:312 [inline]
 prepare_alloc_pages.constprop.0+0x155/0x560 mm/page_alloc.c:4346
 __alloc_pages+0x194/0x2460 mm/page_alloc.c:4564
 __alloc_pages_node include/linux/gfp.h:238 [inline]
 alloc_pages_node include/linux/gfp.h:261 [inline]
 __kmalloc_large_node+0x7f/0x1a0 mm/slub.c:3911
 kmalloc_large+0x1c/0x70 mm/slub.c:3928
 kmalloc include/linux/slab.h:625 [inline]
 diMount+0x29/0x8d0 fs/jfs/jfs_imap.c:105
 jfs_mount_rw+0x238/0x700 fs/jfs/jfs_mount.c:240
 jfs_remount+0x51f/0x650 fs/jfs/super.c:454
 legacy_reconfigure+0x119/0x180 fs/fs_context.c:685
 reconfigure_super+0x44f/0xb20 fs/super.c:1071
 vfs_cmd_reconfigure fs/fsopen.c:267 [inline]
 vfs_fsconfig_locked fs/fsopen.c:296 [inline]
 __do_sys_fsconfig+0x991/0xb90 fs/fsopen.c:476
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:321
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:346
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7324579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f5f165ac EFLAGS: 00000292 ORIG_RAX: 00000000000001af
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000000007
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

 ... Log Wrap ... Log Wrap ... Log Wrap ...

----------------
Code disassembly (best guess), 2 bytes skipped:
   0:	10 06                	adc    %al,(%rsi)
   2:	03 74 b4 01          	add    0x1(%rsp,%rsi,4),%esi
   6:	10 07                	adc    %al,(%rdi)
   8:	03 74 b0 01          	add    0x1(%rax,%rsi,4),%esi
   c:	10 08                	adc    %cl,(%rax)
   e:	03 74 d8 01          	add    0x1(%rax,%rbx,8),%esi
  1e:	00 51 52             	add    %dl,0x52(%rcx)
  21:	55                   	push   %rbp
  22:	89 e5                	mov    %esp,%ebp
  24:	0f 34                	sysenter
  26:	cd 80                	int    $0x80
* 28:	5d                   	pop    %rbp <-- trapping instruction
  29:	5a                   	pop    %rdx
  2a:	59                   	pop    %rcx
  2b:	c3                   	ret
  2c:	90                   	nop
  2d:	90                   	nop
  2e:	90                   	nop
  2f:	90                   	nop
  30:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi
  37:	8d b4 26 00 00 00 00 	lea    0x0(%rsi,%riz,1),%esi

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/19 22:36 upstream dbe0a7be2838 af24b050 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in jfs_mount_rw
* Struck through repros no longer work on HEAD.