syzbot


possible deadlock in lock_mm_and_find_vma (3)

Status: upstream: reported on 2024/12/04 07:31
Subsystems: ntfs3
[Documentation on labels]
Reported-by: syzbot+936adc4458c5f973d899@syzkaller.appspotmail.com
First crash: 21d, last: 21d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [ntfs3?] possible deadlock in lock_mm_and_find_vma (3) 0 (1) 2024/12/04 07:31
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream possible deadlock in lock_mm_and_find_vma (2) mm C 6626 40d 112d 28/28 fixed on 2024/11/14 10:09
upstream possible deadlock in lock_mm_and_find_vma exfat C error 2 507d 526d 23/28 fixed on 2023/10/12 12:48

Sample crash report:
======================================================
WARNING: possible circular locking dependency detected
6.12.0-syzkaller-10740-g509f806f7f70 #0 Not tainted
------------------------------------------------------
syz.3.1412/11243 is trying to acquire lock:
ffff8880276e4fe0 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_lock_killable include/linux/mmap_lock.h:153 [inline]
ffff8880276e4fe0 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6158 [inline]
ffff8880276e4fe0 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x3a9/0x6a0 mm/memory.c:6209

but task is already holding lock:
ffff88804d648af0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_trylock include/linux/fs.h:838 [inline]
ffff88804d648af0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: ntfs_file_write_iter+0x19d/0x2300 fs/ntfs3/file.c:1240

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}:
       down_write+0x93/0x200 kernel/locking/rwsem.c:1577
       inode_lock include/linux/fs.h:818 [inline]
       ntfs_file_mmap+0x610/0x780 fs/ntfs3/file.c:379
       call_mmap include/linux/fs.h:2183 [inline]
       mmap_file mm/internal.h:124 [inline]
       __mmap_new_file_vma mm/vma.c:2291 [inline]
       __mmap_new_vma mm/vma.c:2355 [inline]
       __mmap_region+0x1789/0x2670 mm/vma.c:2456
       mmap_region+0x270/0x320 mm/mmap.c:1347
       do_mmap+0xc00/0xfc0 mm/mmap.c:496
       vm_mmap_pgoff+0x1ba/0x360 mm/util.c:580
       ksys_mmap_pgoff+0x32c/0x5c0 mm/mmap.c:542
       __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline]
       __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline]
       __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&mm->mmap_lock){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3161 [inline]
       check_prevs_add kernel/locking/lockdep.c:3280 [inline]
       validate_chain kernel/locking/lockdep.c:3904 [inline]
       __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
       lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
       down_read_killable+0x9d/0x380 kernel/locking/rwsem.c:1547
       mmap_read_lock_killable include/linux/mmap_lock.h:153 [inline]
       get_mmap_lock_carefully mm/memory.c:6158 [inline]
       lock_mm_and_find_vma+0x3a9/0x6a0 mm/memory.c:6209
       do_user_addr_fault+0x2b5/0x13f0 arch/x86/mm/fault.c:1361
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
       fault_in_readable+0xee/0x200 mm/gup.c:2228
       fault_in_iov_iter_readable+0x101/0x2c0 lib/iov_iter.c:94
       generic_perform_write+0x21b/0x920 mm/filemap.c:4045
       __generic_file_write_iter+0x1f7/0x240 mm/filemap.c:4156
       ntfs_file_write_iter+0xe4e/0x2300 fs/ntfs3/file.c:1267
       new_sync_write fs/read_write.c:586 [inline]
       vfs_write+0x5b1/0x1150 fs/read_write.c:679
       ksys_pwrite64 fs/read_write.c:786 [inline]
       __do_sys_pwrite64 fs/read_write.c:794 [inline]
       __se_sys_pwrite64 fs/read_write.c:791 [inline]
       __x64_sys_pwrite64+0x1f6/0x250 fs/read_write.c:791
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&sb->s_type->i_mutex_key#24);
                               lock(&mm->mmap_lock);
                               lock(&sb->s_type->i_mutex_key#24);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

2 locks held by syz.3.1412/11243:
 #0: ffff888025344420 (sb_writers#17){.+.+}-{0:0}, at: ksys_pwrite64 fs/read_write.c:786 [inline]
 #0: ffff888025344420 (sb_writers#17){.+.+}-{0:0}, at: __do_sys_pwrite64 fs/read_write.c:794 [inline]
 #0: ffff888025344420 (sb_writers#17){.+.+}-{0:0}, at: __se_sys_pwrite64 fs/read_write.c:791 [inline]
 #0: ffff888025344420 (sb_writers#17){.+.+}-{0:0}, at: __x64_sys_pwrite64+0x1f6/0x250 fs/read_write.c:791
 #1: ffff88804d648af0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: inode_trylock include/linux/fs.h:838 [inline]
 #1: ffff88804d648af0 (&sb->s_type->i_mutex_key#24){+.+.}-{4:4}, at: ntfs_file_write_iter+0x19d/0x2300 fs/ntfs3/file.c:1240

stack backtrace:
CPU: 0 UID: 0 PID: 11243 Comm: syz.3.1412 Not tainted 6.12.0-syzkaller-10740-g509f806f7f70 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
 print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074
 check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2206
 check_prev_add kernel/locking/lockdep.c:3161 [inline]
 check_prevs_add kernel/locking/lockdep.c:3280 [inline]
 validate_chain kernel/locking/lockdep.c:3904 [inline]
 __lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5226
 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849
 down_read_killable+0x9d/0x380 kernel/locking/rwsem.c:1547
 mmap_read_lock_killable include/linux/mmap_lock.h:153 [inline]
 get_mmap_lock_carefully mm/memory.c:6158 [inline]
 lock_mm_and_find_vma+0x3a9/0x6a0 mm/memory.c:6209
 do_user_addr_fault+0x2b5/0x13f0 arch/x86/mm/fault.c:1361
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:fault_in_readable+0xee/0x200 mm/gup.c:2228
Code: 01 cb 0f ae e8 4d 89 ee 31 ff 41 81 e6 ff 0f 00 00 4c 89 f6 e8 c3 c9 b9 ff 4d 85 f6 0f 84 f2 00 00 00 e8 45 c7 b9 ff 45 31 f6 <41> 8a 45 00 31 ff 44 89 f6 88 44 24 28 e8 70 c9 b9 ff 45 85 f6 0f
RSP: 0018:ffffc9000f977968 EFLAGS: 00050246
RAX: 00000000000058a3 RBX: 0000000000000000 RCX: ffffc9000cf2b000
RDX: 0000000000080000 RSI: ffffffff81d4fd3b RDI: 0000000000000007
RBP: 000000002000ff2f R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000274 R11: 0000000000000000 R12: 0000000000000cbb
R13: 000000002000f274 R14: 0000000000000000 R15: 1ffff92001f2ef2e
 fault_in_iov_iter_readable+0x101/0x2c0 lib/iov_iter.c:94
 generic_perform_write+0x21b/0x920 mm/filemap.c:4045
 __generic_file_write_iter+0x1f7/0x240 mm/filemap.c:4156
 ntfs_file_write_iter+0xe4e/0x2300 fs/ntfs3/file.c:1267
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x5b1/0x1150 fs/read_write.c:679
 ksys_pwrite64 fs/read_write.c:786 [inline]
 __do_sys_pwrite64 fs/read_write.c:794 [inline]
 __se_sys_pwrite64 fs/read_write.c:791 [inline]
 __x64_sys_pwrite64+0x1f6/0x250 fs/read_write.c:791
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0e30780849
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f0e314c6058 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f0e30945fa0 RCX: 00007f0e30780849
RDX: 000000000000fdef RSI: 0000000020000140 RDI: 0000000000000005
RBP: 00007f0e307f3986 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fecc R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f0e30945fa0 R15: 00007ffe3585a1a8
 </TASK>
----------------
Code disassembly (best guess):
   0:	01 cb                	add    %ecx,%ebx
   2:	0f ae e8             	lfence
   5:	4d 89 ee             	mov    %r13,%r14
   8:	31 ff                	xor    %edi,%edi
   a:	41 81 e6 ff 0f 00 00 	and    $0xfff,%r14d
  11:	4c 89 f6             	mov    %r14,%rsi
  14:	e8 c3 c9 b9 ff       	call   0xffb9c9dc
  19:	4d 85 f6             	test   %r14,%r14
  1c:	0f 84 f2 00 00 00    	je     0x114
  22:	e8 45 c7 b9 ff       	call   0xffb9c76c
  27:	45 31 f6             	xor    %r14d,%r14d
* 2a:	41 8a 45 00          	mov    0x0(%r13),%al <-- trapping instruction
  2e:	31 ff                	xor    %edi,%edi
  30:	44 89 f6             	mov    %r14d,%esi
  33:	88 44 24 28          	mov    %al,0x28(%rsp)
  37:	e8 70 c9 b9 ff       	call   0xffb9c9ac
  3c:	45 85 f6             	test   %r14d,%r14d
  3f:	0f                   	.byte 0xf

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/30 07:29 upstream 509f806f7f70 68914665 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root possible deadlock in lock_mm_and_find_vma
* Struck through repros no longer work on HEAD.