syzbot


possible deadlock in __jfs_setxattr

Status: upstream: reported on 2024/06/29 10:05
Subsystems: jfs
[Documentation on labels]
Reported-by: syzbot+6b5a66ea06e836f7d821@syzkaller.appspotmail.com
First crash: 23d, last: 23d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [jfs?] possible deadlock in __jfs_setxattr 0 (1) 2024/06/29 10:05

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc5-syzkaller-00018-g55027e689933 #0 Not tainted
------------------------------------------------------
syz-executor.2/16354 is trying to acquire lock:
ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:334 [inline]
ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: prepare_alloc_pages.constprop.0+0x155/0x560 mm/page_alloc.c:4449

but task is already holding lock:
ffff88804b8b2760 (&jfs_ip->xattr_sem){++++}-{3:3}, at: __jfs_setxattr+0x10a/0xfb0 fs/jfs/xattr.c:671

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #4 (&jfs_ip->xattr_sem){++++}-{3:3}:
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1579
       __jfs_setxattr+0x10a/0xfb0 fs/jfs/xattr.c:671
       __jfs_xattr_set+0xc6/0x150 fs/jfs/xattr.c:919
       __vfs_setxattr+0x173/0x1e0 fs/xattr.c:200
       __vfs_setxattr_noperm+0x127/0x660 fs/xattr.c:234
       __vfs_setxattr_locked+0x182/0x260 fs/xattr.c:295
       vfs_setxattr+0x146/0x350 fs/xattr.c:321
       do_setxattr+0x146/0x170 fs/xattr.c:629
       setxattr+0x15d/0x180 fs/xattr.c:652
       path_setxattr+0x179/0x1e0 fs/xattr.c:671
       __do_sys_lsetxattr fs/xattr.c:694 [inline]
       __se_sys_lsetxattr fs/xattr.c:690 [inline]
       __ia32_sys_lsetxattr+0xbd/0x160 fs/xattr.c:690
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #3 (&jfs_ip->commit_mutex){+.+.}-{3:3}:
       __mutex_lock_common kernel/locking/mutex.c:608 [inline]
       __mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
       diNewIAG fs/jfs/jfs_imap.c:2519 [inline]
       diAllocExt fs/jfs/jfs_imap.c:1902 [inline]
       diAllocAG+0xc59/0x2300 fs/jfs/jfs_imap.c:1666
       diAlloc+0x8f7/0x1a70 fs/jfs/jfs_imap.c:1587
       ialloc+0x84/0x9e0 fs/jfs/jfs_inode.c:56
       jfs_mkdir+0x244/0xb30 fs/jfs/namei.c:225
       vfs_mkdir+0x57d/0x860 fs/namei.c:4131
       do_mkdirat+0x301/0x3a0 fs/namei.c:4154
       __do_sys_mkdirat fs/namei.c:4169 [inline]
       __se_sys_mkdirat fs/namei.c:4167 [inline]
       __ia32_sys_mkdirat+0x84/0xb0 fs/namei.c:4167
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

-> #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_create+0x23e/0xb40 fs/jfs/namei.c:92
       lookup_open.isra.0+0x10a1/0x13c0 fs/namei.c:3505
       open_last_lookups fs/namei.c:3574 [inline]
       path_openat+0x92f/0x29f0 fs/namei.c:3804
       do_filp_open+0x1dc/0x430 fs/namei.c:3834
       do_sys_openat2+0x17a/0x1e0 fs/open.c:1405
       do_sys_open fs/open.c:1420 [inline]
       __do_compat_sys_openat fs/open.c:1480 [inline]
       __se_compat_sys_openat fs/open.c:1478 [inline]
       __ia32_compat_sys_openat+0x16e/0x210 fs/open.c:1478
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
       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+0x295/0x480 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:4790
       shrink_many mm/vmscan.c:4851 [inline]
       lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
       shrink_node mm/vmscan.c:5910 [inline]
       kswapd_shrink_node mm/vmscan.c:6720 [inline]
       balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
       kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
       kthread+0x2c1/0x3a0 kernel/kthread.c:389
       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:3801 [inline]
       fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815
       might_alloc include/linux/sched/mm.h:334 [inline]
       prepare_alloc_pages.constprop.0+0x155/0x560 mm/page_alloc.c:4449
       __alloc_pages_noprof+0x194/0x2460 mm/page_alloc.c:4667
       __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
       alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
       __kmalloc_large_node+0x7f/0x1a0 mm/slub.c:4067
       __do_kmalloc_node mm/slub.c:4110 [inline]
       __kmalloc_noprof.cold+0xc/0x61 mm/slub.c:4135
       kmalloc_noprof include/linux/slab.h:664 [inline]
       ea_get+0x21f/0x12c0 fs/jfs/xattr.c:487
       __jfs_setxattr+0x1ed/0xfb0 fs/jfs/xattr.c:720
       __jfs_xattr_set+0xc6/0x150 fs/jfs/xattr.c:919
       __vfs_setxattr+0x173/0x1e0 fs/xattr.c:200
       __vfs_setxattr_noperm+0x127/0x660 fs/xattr.c:234
       __vfs_setxattr_locked+0x182/0x260 fs/xattr.c:295
       vfs_setxattr+0x146/0x350 fs/xattr.c:321
       do_setxattr+0x146/0x170 fs/xattr.c:629
       setxattr+0x15d/0x180 fs/xattr.c:652
       path_setxattr+0x179/0x1e0 fs/xattr.c:671
       __do_sys_setxattr fs/xattr.c:687 [inline]
       __se_sys_setxattr fs/xattr.c:683 [inline]
       __ia32_sys_setxattr+0xc0/0x160 fs/xattr.c:683
       do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
       __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
       do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
       entry_SYSENTER_compat_after_hwframe+0x84/0x8e

other info that might help us debug this:

Chain exists of:
  fs_reclaim --> &jfs_ip->commit_mutex --> &jfs_ip->xattr_sem

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&jfs_ip->xattr_sem);
                               lock(&jfs_ip->commit_mutex);
                               lock(&jfs_ip->xattr_sem);
  lock(fs_reclaim);

 *** DEADLOCK ***

4 locks held by syz-executor.2/16354:
 #0: ffff888057c08420 (sb_writers#27){.+.+}-{0:0}, at: path_setxattr+0xc3/0x1e0 fs/xattr.c:669
 #1: ffff88804b8b2a80 (&sb->s_type->i_mutex_key#36){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline]
 #1: ffff88804b8b2a80 (&sb->s_type->i_mutex_key#36){+.+.}-{3:3}, at: vfs_setxattr+0x123/0x350 fs/xattr.c:320
 #2: ffff88804b8b26c8 (&jfs_ip->commit_mutex){+.+.}-{3:3}, at: __jfs_xattr_set+0xad/0x150 fs/jfs/xattr.c:918
 #3: ffff88804b8b2760 (&jfs_ip->xattr_sem){++++}-{3:3}, at: __jfs_setxattr+0x10a/0xfb0 fs/jfs/xattr.c:671

stack backtrace:
CPU: 3 PID: 16354 Comm: syz-executor.2 Not tainted 6.10.0-rc5-syzkaller-00018-g55027e689933 #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:3801 [inline]
 fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815
 might_alloc include/linux/sched/mm.h:334 [inline]
 prepare_alloc_pages.constprop.0+0x155/0x560 mm/page_alloc.c:4449
 __alloc_pages_noprof+0x194/0x2460 mm/page_alloc.c:4667
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 __kmalloc_large_node+0x7f/0x1a0 mm/slub.c:4067
 __do_kmalloc_node mm/slub.c:4110 [inline]
 __kmalloc_noprof.cold+0xc/0x61 mm/slub.c:4135
 kmalloc_noprof include/linux/slab.h:664 [inline]
 ea_get+0x21f/0x12c0 fs/jfs/xattr.c:487
 __jfs_setxattr+0x1ed/0xfb0 fs/jfs/xattr.c:720
 __jfs_xattr_set+0xc6/0x150 fs/jfs/xattr.c:919
 __vfs_setxattr+0x173/0x1e0 fs/xattr.c:200
 __vfs_setxattr_noperm+0x127/0x660 fs/xattr.c:234
 __vfs_setxattr_locked+0x182/0x260 fs/xattr.c:295
 vfs_setxattr+0x146/0x350 fs/xattr.c:321
 do_setxattr+0x146/0x170 fs/xattr.c:629
 setxattr+0x15d/0x180 fs/xattr.c:652
 path_setxattr+0x179/0x1e0 fs/xattr.c:671
 __do_sys_setxattr fs/xattr.c:687 [inline]
 __se_sys_setxattr fs/xattr.c:683 [inline]
 __ia32_sys_setxattr+0xc0/0x160 fs/xattr.c:683
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7320579
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:00000000f5ed05ac EFLAGS: 00000292 ORIG_RAX: 00000000000000e2
RAX: ffffffffffffffda RBX: 0000000020000100 RCX: 0000000020000140
RDX: 0000000020000180 RSI: 000000000000e00f RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
----------------
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
2024/06/25 09:58 upstream 55027e689933 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in __jfs_setxattr
* Struck through repros no longer work on HEAD.