syzbot


possible deadlock in udf_file_write_iter

Status: auto-obsoleted due to no activity on 2024/09/26 15:19
Subsystems: udf
[Documentation on labels]
Reported-by: syzbot+b8bf17b888663bcdee61@syzkaller.appspotmail.com
First crash: 135d, last: 111d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [udf?] possible deadlock in udf_file_write_iter 0 (1) 2024/05/29 20:41
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 possible deadlock in udf_file_write_iter udf 1 623d 623d 0/1 upstream: reported on 2023/01/24 07:13

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #0 Not tainted
------------------------------------------------------
syz-executor.2/9838 is trying to acquire lock:
ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:334 [inline]
ffffffff8dd3aac0 (fs_reclaim){+.+.}-{0:0}, at: prepare_alloc_pages.constprop.0+0x155/0x560 mm/page_alloc.c:4449

but task is already holding lock:
ffff8880658b3788 (mapping.invalidate_lock#8){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:836 [inline]
ffff8880658b3788 (mapping.invalidate_lock#8){++++}-{3:3}, at: udf_file_write_iter+0x5c2/0x740 fs/udf/file.c:104

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (mapping.invalidate_lock#8){++++}-{3:3}:
       down_write+0x3a/0x50 kernel/locking/rwsem.c:1579
       filemap_invalidate_lock include/linux/fs.h:836 [inline]
       udf_setsize+0x256/0x1180 fs/udf/inode.c:1253
       udf_evict_inode+0x361/0x590 fs/udf/inode.c:144
       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_mpol_noprof+0x275/0x610 mm/mempolicy.c:2265
       folio_alloc_noprof+0x1e/0xc0 mm/mempolicy.c:2343
       filemap_alloc_folio_noprof+0x3ba/0x490 mm/filemap.c:1008
       __filemap_get_folio+0x51e/0xa80 mm/filemap.c:1950
       udf_expand_file_adinicb+0xe9/0x940 fs/udf/inode.c:358
       udf_file_write_iter+0x5ca/0x740 fs/udf/file.c:105
       new_sync_write fs/read_write.c:497 [inline]
       vfs_write+0x6b6/0x1140 fs/read_write.c:590
       ksys_write+0x12f/0x260 fs/read_write.c:643
       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:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(mapping.invalidate_lock#8);
                               lock(fs_reclaim);
                               lock(mapping.invalidate_lock#8);
  lock(fs_reclaim);

 *** DEADLOCK ***

4 locks held by syz-executor.2/9838:
 #0: ffff88801cae5748 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xeb/0x180 fs/file.c:1191
 #1: ffff888055420420 (sb_writers#31){.+.+}-{0:0}, at: ksys_write+0x12f/0x260 fs/read_write.c:643
 #2: ffff8880658b35e8 (&sb->s_type->i_mutex_key#37){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:791 [inline]
 #2: ffff8880658b35e8 (&sb->s_type->i_mutex_key#37){+.+.}-{3:3}, at: udf_file_write_iter+0x73/0x740 fs/udf/file.c:95
 #3: ffff8880658b3788 (mapping.invalidate_lock#8){++++}-{3:3}, at: filemap_invalidate_lock include/linux/fs.h:836 [inline]
 #3: ffff8880658b3788 (mapping.invalidate_lock#8){++++}-{3:3}, at: udf_file_write_iter+0x5c2/0x740 fs/udf/file.c:104

stack backtrace:
CPU: 0 PID: 9838 Comm: syz-executor.2 Not tainted 6.10.0-rc3-syzkaller-00044-g2ccbdf43d5e7 #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_mpol_noprof+0x275/0x610 mm/mempolicy.c:2265
 folio_alloc_noprof+0x1e/0xc0 mm/mempolicy.c:2343
 filemap_alloc_folio_noprof+0x3ba/0x490 mm/filemap.c:1008
 __filemap_get_folio+0x51e/0xa80 mm/filemap.c:1950
 udf_expand_file_adinicb+0xe9/0x940 fs/udf/inode.c:358
 udf_file_write_iter+0x5ca/0x740 fs/udf/file.c:105
 new_sync_write fs/read_write.c:497 [inline]
 vfs_write+0x6b6/0x1140 fs/read_write.c:590
 ksys_write+0x12f/0x260 fs/read_write.c:643
 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: 0023:0xf7300579
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:00000000f5ef25ac EFLAGS: 00000292 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000020000200
RDX: 00000000175d9003 RSI: 0000000000000000 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 (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/06/18 15:19 upstream 2ccbdf43d5e7 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in udf_file_write_iter
2024/05/25 22:30 upstream 54f71b0369c9 c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in udf_file_write_iter
2024/05/25 20:36 upstream 56fb6f92854f c2e07261 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 possible deadlock in udf_file_write_iter
* Struck through repros no longer work on HEAD.