syzbot

======================================================
WARNING: possible circular locking dependency detected
6.1.120-syzkaller-00773-g52f863f820fd #0 Tainted: G        W         
------------------------------------------------------
syz-executor858/4246 is trying to acquire lock:
ffff88807b2d17d8 (&mm->mmap_lock){++++}-{3:3}, at: mmap_read_lock_killable+0x1d/0x60 include/linux/mmap_lock.h:126

but task is already holding lock:
ffff88802e5b8f30 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff88802e5b8f30 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x310 mm/filemap.c:4002

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+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:758 [inline]
       process_measurement+0x446/0x21b0 security/integrity/ima/ima_main.c:242
       ima_file_mmap+0x121/0x1c0 security/integrity/ima/ima_main.c:429
       __do_sys_remap_file_pages mm/mmap.c:3024 [inline]
       __se_sys_remap_file_pages+0x67a/0x8b0 mm/mmap.c:2956
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&mm->mmap_lock){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read_killable+0xc6/0xd10 kernel/locking/rwsem.c:1543
       mmap_read_lock_killable+0x1d/0x60 include/linux/mmap_lock.h:126
       get_mmap_lock_carefully mm/memory.c:5331 [inline]
       lock_mm_and_find_vma+0x2a7/0x2e0 mm/memory.c:5382
       do_user_addr_fault arch/x86/mm/fault.c:1312 [inline]
       handle_page_fault arch/x86/mm/fault.c:1431 [inline]
       exc_page_fault+0x169/0x620 arch/x86/mm/fault.c:1487
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
       fault_in_readable+0x1c8/0x340
       fault_in_iov_iter_readable+0xdb/0x270 lib/iov_iter.c:356
       generic_perform_write+0x207/0x5e0 mm/filemap.c:3835
       __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973
       generic_file_write_iter+0xab/0x310 mm/filemap.c:4005
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x857/0xbc0 fs/read_write.c:584
       ksys_write+0x19c/0x2c0 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

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);
  lock(&mm->mmap_lock);

 *** DEADLOCK ***

3 locks held by syz-executor858/4246:
 #0: ffff88807bd920e8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x2ba/0x360 fs/file.c:1031
 #1: ffff88807465c460 (sb_writers#5){.+.+}-{0:0}, at: vfs_write+0x269/0xbc0 fs/read_write.c:580
 #2: ffff88802e5b8f30 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
 #2: ffff88802e5b8f30 (&sb->s_type->i_mutex_key#12){+.+.}-{3:3}, at: generic_file_write_iter+0x7f/0x310 mm/filemap.c:4002

stack backtrace:
CPU: 0 PID: 4246 Comm: syz-executor858 Tainted: G        W          6.1.120-syzkaller-00773-g52f863f820fd #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 down_read_killable+0xc6/0xd10 kernel/locking/rwsem.c:1543
 mmap_read_lock_killable+0x1d/0x60 include/linux/mmap_lock.h:126
 get_mmap_lock_carefully mm/memory.c:5331 [inline]
 lock_mm_and_find_vma+0x2a7/0x2e0 mm/memory.c:5382
 do_user_addr_fault arch/x86/mm/fault.c:1312 [inline]
 handle_page_fault arch/x86/mm/fault.c:1431 [inline]
 exc_page_fault+0x169/0x620 arch/x86/mm/fault.c:1487
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
RIP: 0010:fault_in_readable+0x1c8/0x340 mm/gup.c:1898
Code: 24 08 4c 8d b0 ff 0f 00 00 48 89 c3 4d 01 e6 49 81 e6 00 f0 ff ff 49 39 c6 72 70 e8 d2 b1 bf ff 4c 39 f3 74 73 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:ffffc90003cb79e0 EFLAGS: 00050287
RAX: ffffffff81caea9e RBX: 00000000209a7000 RCX: ffff8880196c5940
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003cb7a98 R08: ffffffff81caea36 R09: ffffffff844210c5
R10: 0000000000000002 R11: ffff8880196c5940 R12: 0000000000001000
R13: dffffc0000000000 R14: 00000000209a8000 R15: 1ffff92000796f44
 fault_in_iov_iter_readable+0xdb/0x270 lib/iov_iter.c:356
 generic_perform_write+0x207/0x5e0 mm/filemap.c:3835
 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973
 generic_file_write_iter+0xab/0x310 mm/filemap.c:4005
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x857/0xbc0 fs/read_write.c:584
 ksys_write+0x19c/0x2c0 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6a5cde4309
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 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:00007f6a5cda5228 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f6a5ce6e308 RCX: 00007f6a5cde4309
RDX: 000000000208e24b RSI: 0000000020000000 RDI: 0000000000000003
RBP: 00007f6a5ce6e300 R08: 00007f6a5cda56c0 R09: 00007f6a5cda56c0
R10: 00007f6a5cda56c0 R11: 0000000000000246 R12: 00007f6a5ce6e30c
R13: 00007f6a5ce3b004 R14: b635773f06ebbeee R15: 00007ffede2ab288
 </TASK>
----------------
Code disassembly (best guess):
   0:	24 08                	and    $0x8,%al
   2:	4c 8d b0 ff 0f 00 00 	lea    0xfff(%rax),%r14
   9:	48 89 c3             	mov    %rax,%rbx
   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 70                	jb     0x8b
  1b:	e8 d2 b1 bf ff       	call   0xffbfb1f2
  20:	4c 39 f3             	cmp    %r14,%rbx
  23:	74 73                	je     0x98
  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)