[syzbot] [mm?] possible deadlock in shmem_file_write_iter

[syzbot] [mm?] possible deadlock in shmem_file_write_iter

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    e477dba5442c Merge tag 'for-6.12/dm-changes' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=102ade27980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b2d4fdf18a83ec0b
dashboard link: https://syzkaller.appspot.com/bug?extid=288aa6838b3263f52e7e
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/be1e82b0133d/disk-e477dba5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/8d9e4b1a6733/vmlinux-e477dba5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b79025eddfb1/bzImage-e477dba5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+288aa6838b3263f52e7e@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.11.0-syzkaller-11624-ge477dba5442c #0 Not tainted
------------------------------------------------------
syz.2.1702/9983 is trying to acquire lock:
ffff888028091e18 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153

but task is already holding lock:
ffff888077ef3708 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
ffff888077ef3708 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: shmem_file_write_iter+0x80/0x120 mm/shmem.c:3211

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
       down_write+0x99/0x220 kernel/locking/rwsem.c:1579
       inode_lock include/linux/fs.h:815 [inline]
       process_measurement+0x439/0x1fb0 security/integrity/ima/ima_main.c:250
       ima_file_mmap+0x13d/0x2b0 security/integrity/ima/ima_main.c:455
       security_mmap_file+0x7e7/0xa40 security/security.c:2977
       __do_sys_remap_file_pages mm/mmap.c:1692 [inline]
       __se_sys_remap_file_pages+0x6e6/0xa50 mm/mmap.c:1624
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3158 [inline]
       check_prevs_add kernel/locking/lockdep.c:3277 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901
       __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
       down_read_killable+0xca/0xd30 kernel/locking/rwsem.c:1549
       mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153
       get_mmap_lock_carefully mm/memory.c:6108 [inline]
       lock_mm_and_find_vma+0x29c/0x2f0 mm/memory.c:6159
       do_user_addr_fault arch/x86/mm/fault.c:1361 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
       fault_in_readable+0x165/0x2b0
       fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94
       generic_perform_write+0x259/0x6d0 mm/filemap.c:4040
       shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3221
       new_sync_write fs/read_write.c:590 [inline]
       vfs_write+0xa6f/0xc90 fs/read_write.c:683
       ksys_write+0x183/0x2b0 fs/read_write.c:736
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 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#12);
                               lock(&mm->mmap_lock);
                               lock(&sb->s_type->i_mutex_key#12);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

3 locks held by syz.2.1702/9983:
 #0: ffff888054784478 (&f->f_pos_lock){+.+.}-{3:3}, at: fdget_pos+0x24e/0x320 fs/file.c:1187
 #1: ffff88814a584420 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #1: ffff88814a584420 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679
 #2: ffff888077ef3708 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #2: ffff888077ef3708 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: shmem_file_write_iter+0x80/0x120 mm/shmem.c:3211

stack backtrace:
CPU: 1 UID: 0 PID: 9983 Comm: syz.2.1702 Not tainted 6.11.0-syzkaller-11624-ge477dba5442c #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+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2203
 check_prev_add kernel/locking/lockdep.c:3158 [inline]
 check_prevs_add kernel/locking/lockdep.c:3277 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
 down_read_killable+0xca/0xd30 kernel/locking/rwsem.c:1549
 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153
 get_mmap_lock_carefully mm/memory.c:6108 [inline]
 lock_mm_and_find_vma+0x29c/0x2f0 mm/memory.c:6159
 do_user_addr_fault arch/x86/mm/fault.c:1361 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:fault_in_readable+0x165/0x2b0 mm/gup.c:2235
Code: b3 ff 4c 8d b3 ff 0f 00 00 48 89 d8 4d 01 e6 49 81 e6 00 f0 ff ff 49 39 c6 72 6b e8 f5 c8 b3 ff 4c 39 f3 74 6e 4c 89 64 24 10 <44> 8a 23 43 0f b6 04 2f 84 c0 75 18 44 88 64 24 40 48 81 c3 00 10
RSP: 0018:ffffc900045c7a40 EFLAGS: 00050283
RAX: ffffffff81e0eba7 RBX: 00000000201e1000 RCX: 0000000000040000
RDX: ffffc9001ddf8000 RSI: 000000000000bffd RDI: 000000000000bffe
RBP: ffffc900045c7af8 R08: ffffffff81e0eb18 R09: ffffffff84b912a9
R10: 0000000000000002 R11: ffff888025213c00 R12: 0000000000200000
R13: dffffc0000000000 R14: 0000000020201000 R15: 1ffff920008b8f50
 fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94
 generic_perform_write+0x259/0x6d0 mm/filemap.c:4040
 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3221
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xa6f/0xc90 fs/read_write.c:683
 ksys_write+0x183/0x2b0 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbca257df39
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:00007fbca3459038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fbca2735f80 RCX: 00007fbca257df39
RDX: 000000000208e24b RSI: 0000000020000100 RDI: 0000000000000003
RBP: 00007fbca25f0216 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fbca2735f80 R15: 00007ffd5bf037c8
 </TASK>
----------------
Code disassembly (best guess):
   0:	b3 ff                	mov    $0xff,%bl
   2:	4c 8d b3 ff 0f 00 00 	lea    0xfff(%rbx),%r14
   9:	48 89 d8             	mov    %rbx,%rax
   c:	4d 01 e6             	add    %r12,%r14
   f:	49 81 e6 00 f0 ff ff 	and    $0xfffffffffffff000,%r14
  16:	49 39 c6             	cmp    %rax,%r14
  19:	72 6b                	jb     0x86
  1b:	e8 f5 c8 b3 ff       	call   0xffb3c915
  20:	4c 39 f3             	cmp    %r14,%rbx
  23:	74 6e                	je     0x93
  25:	4c 89 64 24 10       	mov    %r12,0x10(%rsp)
* 2a:	44 8a 23             	mov    (%rbx),%r12b <-- trapping instruction
  2d:	43 0f b6 04 2f       	movzbl (%r15,%r13,1),%eax
  32:	84 c0                	test   %al,%al
  34:	75 18                	jne    0x4e
  36:	44 88 64 24 40       	mov    %r12b,0x40(%rsp)
  3b:	48                   	rex.W
  3c:	81                   	.byte 0x81
  3d:	c3                   	ret
  3e:	00 10                	add    %dl,(%rax)


---
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Re: [syzbot] [mm?] possible deadlock in shmem_file_write_iter

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    3efc57369a0c Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
console+strace: https://syzkaller.appspot.com/x/log.txt?x=1648f507980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a4fcb065287cdb84
dashboard link: https://syzkaller.appspot.com/bug?extid=288aa6838b3263f52e7e
compiler:       Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17af2980580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11607d9f980000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/b5a4faec7a99/disk-3efc5736.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/971adf9a5295/vmlinux-3efc5736.xz
kernel image: https://storage.googleapis.com/syzbot-assets/49516da34e16/bzImage-3efc5736.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+288aa6838b3263f52e7e@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.11.0-syzkaller-11993-g3efc57369a0c #0 Not tainted
------------------------------------------------------
syz-executor601/5480 is trying to acquire lock:
ffff888021316098 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153

but task is already holding lock:
ffff8880120b02c8 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
ffff8880120b02c8 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: shmem_file_write_iter+0x80/0x120 mm/shmem.c:3211

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
       down_write+0x99/0x220 kernel/locking/rwsem.c:1579
       inode_lock include/linux/fs.h:815 [inline]
       process_measurement+0x439/0x1fb0 security/integrity/ima/ima_main.c:250
       ima_file_mmap+0x13d/0x2b0 security/integrity/ima/ima_main.c:455
       security_mmap_file+0x7e7/0xa40 security/security.c:2977
       __do_sys_remap_file_pages mm/mmap.c:1692 [inline]
       __se_sys_remap_file_pages+0x6e6/0xa50 mm/mmap.c:1624
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
       entry_SYSCALL_64_after_hwframe+0x77/0x7f

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3158 [inline]
       check_prevs_add kernel/locking/lockdep.c:3277 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901
       __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
       down_read_killable+0xca/0xd30 kernel/locking/rwsem.c:1549
       mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153
       get_mmap_lock_carefully mm/memory.c:6108 [inline]
       lock_mm_and_find_vma+0x29c/0x2f0 mm/memory.c:6159
       do_user_addr_fault arch/x86/mm/fault.c:1361 [inline]
       handle_page_fault arch/x86/mm/fault.c:1481 [inline]
       exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
       fault_in_readable+0x165/0x2b0
       fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94
       generic_perform_write+0x259/0x6d0 mm/filemap.c:4044
       shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3221
       new_sync_write fs/read_write.c:590 [inline]
       vfs_write+0xa6d/0xc90 fs/read_write.c:683
       ksys_write+0x183/0x2b0 fs/read_write.c:736
       do_syscall_x64 arch/x86/entry/common.c:52 [inline]
       do_syscall_64+0xf3/0x230 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#12);
                               lock(&mm->mmap_lock);
                               lock(&sb->s_type->i_mutex_key#12);
  rlock(&mm->mmap_lock);

 *** DEADLOCK ***

3 locks held by syz-executor601/5480:
 #0: ffff888028a922b8 (&f->f_pos_lock){+.+.}-{3:3}, at: fdget_pos+0x24e/0x320 fs/file.c:1187
 #1: ffff888076168420 (sb_writers#5){.+.+}-{0:0}, at: file_start_write include/linux/fs.h:2931 [inline]
 #1: ffff888076168420 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x224/0xc90 fs/read_write.c:679
 #2: ffff8880120b02c8 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:815 [inline]
 #2: ffff8880120b02c8 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: shmem_file_write_iter+0x80/0x120 mm/shmem.c:3211

stack backtrace:
CPU: 1 UID: 0 PID: 5480 Comm: syz-executor601 Not tainted 6.11.0-syzkaller-11993-g3efc57369a0c #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+0x241/0x360 lib/dump_stack.c:120
 print_circular_bug+0x13a/0x1b0 kernel/locking/lockdep.c:2074
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2203
 check_prev_add kernel/locking/lockdep.c:3158 [inline]
 check_prevs_add kernel/locking/lockdep.c:3277 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3901
 __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5199
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5822
 down_read_killable+0xca/0xd30 kernel/locking/rwsem.c:1549
 mmap_read_lock_killable+0x1d/0x70 include/linux/mmap_lock.h:153
 get_mmap_lock_carefully mm/memory.c:6108 [inline]
 lock_mm_and_find_vma+0x29c/0x2f0 mm/memory.c:6159
 do_user_addr_fault arch/x86/mm/fault.c:1361 [inline]
 handle_page_fault arch/x86/mm/fault.c:1481 [inline]
 exc_page_fault+0x1bf/0x8c0 arch/x86/mm/fault.c:1539
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:fault_in_readable+0x165/0x2b0 mm/gup.c:2235
Code: b3 ff 4c 8d b3 ff 0f 00 00 48 89 d8 4d 01 e6 49 81 e6 00 f0 ff ff 49 39 c6 72 6b e8 b5 c8 b3 ff 4c 39 f3 74 6e 4c 89 64 24 10 <44> 8a 23 43 0f b6 04 2f 84 c0 75 18 44 88 64 24 40 48 81 c3 00 10
RSP: 0018:ffffc900041e7a40 EFLAGS: 00050293
RAX: ffffffff81e11d97 RBX: 00000000200ee000 RCX: ffff888024029e00
RDX: 0000000000000000 RSI: 0000000000000240 RDI: 0000000000000000
RBP: ffffc900041e7af8 R08: ffffffff81e11d08 R09: ffffffff84b941b9
R10: 0000000000000002 R11: ffff888024029e00 R12: 0000000000200000
R13: dffffc0000000000 R14: 0000000020201000 R15: 1ffff9200083cf50
 fault_in_iov_iter_readable+0x229/0x280 lib/iov_iter.c:94
 generic_perform_write+0x259/0x6d0 mm/filemap.c:4044
 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3221
 new_sync_write fs/read_write.c:590 [inline]
 vfs_write+0xa6d/0xc90 fs/read_write.c:683
 ksys_write+0x183/0x2b0 fs/read_write.c:736
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd0953e3829
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd09537c238 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fd09546e3d8 RCX: 00007fd0953e3829
RDX: 000000000208e24b RSI: 0000000020000240 RDI: 0000000000000003
RBP: 00007fd09546e3d0 R08: 00007fd09537c6c0 R09: 00007fd09537c6c0
R10: 00007fd09537c6c0 R11: 0000000000000246 R12: 00007fd09546e3dc
R13: 000000000000006e R14: 00007ffc57bc6200 R15: 00007ffc57bc62e8
 </TASK>
----------------
Code disassembly (best guess):
   0:	b3 ff                	mov    $0xff,%bl
   2:	4c 8d b3 ff 0f 00 00 	lea    0xfff(%rbx),%r14
   9:	48 89 d8             	mov    %rbx,%rax
   c:	4d 01 e6             	add    %r12,%r14
   f:	49 81 e6 00 f0 ff ff 	and    $0xfffffffffffff000,%r14
  16:	49 39 c6             	cmp    %rax,%r14
  19:	72 6b                	jb     0x86
  1b:	e8 b5 c8 b3 ff       	call   0xffb3c8d5
  20:	4c 39 f3             	cmp    %r14,%rbx
  23:	74 6e                	je     0x93
  25:	4c 89 64 24 10       	mov    %r12,0x10(%rsp)
* 2a:	44 8a 23             	mov    (%rbx),%r12b <-- trapping instruction
  2d:	43 0f b6 04 2f       	movzbl (%r15,%r13,1),%eax
  32:	84 c0                	test   %al,%al
  34:	75 18                	jne    0x4e
  36:	44 88 64 24 40       	mov    %r12b,0x40(%rsp)
  3b:	48                   	rex.W
  3c:	81                   	.byte 0x81
  3d:	c3                   	ret
  3e:	00 10                	add    %dl,(%rax)


---
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.

Re: [syzbot] [mm?] possible deadlock in shmem_file_write_iter

[syzbot]

syzbot has bisected this issue to:

commit ea7e2d5e49c05e5db1922387b09ca74aa40f46e2
Author: Shu Han <ebpqwerty472123@gmail.com>
Date:   Tue Sep 17 09:41:04 2024 +0000

    mm: call the security_mmap_file() LSM hook in remap_file_pages()

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=110d4ea9980000
start commit:   3efc57369a0c Merge tag 'for-linus' of git://git.kernel.org..
git tree:       upstream
final oops:     https://syzkaller.appspot.com/x/report.txt?x=130d4ea9980000
console output: https://syzkaller.appspot.com/x/log.txt?x=150d4ea9980000
kernel config:  https://syzkaller.appspot.com/x/.config?x=a4fcb065287cdb84
dashboard link: https://syzkaller.appspot.com/bug?extid=288aa6838b3263f52e7e
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17af2980580000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11607d9f980000

Reported-by: syzbot+288aa6838b3263f52e7e@syzkaller.appspotmail.com
Fixes: ea7e2d5e49c0 ("mm: call the security_mmap_file() LSM hook in remap_file_pages()")

For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] [mm?] possible deadlock in shmem_file_write_iter

[Shu Han]

It seems to be the same as [1].
Link: https://lore.kernel.org/lkml/20240928065620.7abadb2d8552f03d785c77c9@linux-foundation.org/
[1]

syzbot <syzbot+288aa6838b3263f52e7e@syzkaller.appspotmail.com>
于2024年9月30日周一 14:51写道：
>
> syzbot has bisected this issue to:
>
> commit ea7e2d5e49c05e5db1922387b09ca74aa40f46e2
> Author: Shu Han <ebpqwerty472123@gmail.com>
> Date:   Tue Sep 17 09:41:04 2024 +0000
>
>     mm: call the security_mmap_file() LSM hook in remap_file_pages()
>
> bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=110d4ea9980000
> start commit:   3efc57369a0c Merge tag 'for-linus' of git://git.kernel.org..
> git tree:       upstream
> final oops:     https://syzkaller.appspot.com/x/report.txt?x=130d4ea9980000
> console output: https://syzkaller.appspot.com/x/log.txt?x=150d4ea9980000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=a4fcb065287cdb84
> dashboard link: https://syzkaller.appspot.com/bug?extid=288aa6838b3263f52e7e
> syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=17af2980580000
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=11607d9f980000
>
> Reported-by: syzbot+288aa6838b3263f52e7e@syzkaller.appspotmail.com
> Fixes: ea7e2d5e49c0 ("mm: call the security_mmap_file() LSM hook in remap_file_pages()")
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection

Re: [syzbot] [mm?] possible deadlock in shmem_file_write_iter

[Shu Han]

Have a try to mark this as a dup(if i can do so).

#syz dup: possible deadlock in process_measurement (4)