syzbot

mmap: syz.0.17 (4429) uses deprecated remap_file_pages() syscall. See Documentation/mm/remap_file_pages.rst.
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
syz.0.17/4429 is trying to acquire lock:
ffff888073914e50 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: inode_lock include/linux/fs.h:758 [inline]
ffff888073914e50 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}, at: process_measurement+0x33c/0x1a10 security/integrity/ima/ima_main.c:242

but task is already holding lock:
ffff88807bb83d58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
ffff88807bb83d58 (&mm->mmap_lock){++++}-{3:3}, at: __do_sys_remap_file_pages mm/mmap.c:2993 [inline]
ffff88807bb83d58 (&mm->mmap_lock){++++}-{3:3}, at: __se_sys_remap_file_pages+0x17d/0x770 mm/mmap.c:2968

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (&mm->mmap_lock){++++}-{3:3}:
       down_read_killable+0x4c/0x340 kernel/locking/rwsem.c:1543
       mmap_read_lock_killable+0x1d/0x60 include/linux/mmap_lock.h:126
       get_mmap_lock_carefully mm/memory.c:5333 [inline]
       lock_mm_and_find_vma+0x2b1/0x2f0 mm/memory.c:5384
       do_user_addr_fault+0x2db/0xb10 arch/x86/mm/fault.c:1312
       handle_page_fault arch/x86/mm/fault.c:1431 [inline]
       exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608
       fault_in_readable+0x13e/0x1f0 mm/gup.c:1914
       fault_in_iov_iter_readable+0xbb/0x2e0 lib/iov_iter.c:356
       generic_perform_write+0x1ee/0x5a0 mm/filemap.c:3852
       __generic_file_write_iter+0x148/0x2a0 mm/filemap.c:3960
       generic_file_write_iter+0xab/0x2e0 mm/filemap.c:3989
       call_write_iter include/linux/fs.h:2265 [inline]
       new_sync_write fs/read_write.c:491 [inline]
       vfs_write+0x44c/0x960 fs/read_write.c:584
       ksys_write+0x143/0x240 fs/read_write.c:637
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&sb->s_type->i_mutex_key#13){+.+.}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain kernel/locking/lockdep.c:3825 [inline]
       __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
       lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       inode_lock include/linux/fs.h:758 [inline]
       process_measurement+0x33c/0x1a10 security/integrity/ima/ima_main.c:242
       ima_file_mmap+0x104/0x150 security/integrity/ima/ima_main.c:429
       __do_sys_remap_file_pages mm/mmap.c:3036 [inline]
       __se_sys_remap_file_pages+0x53e/0x770 mm/mmap.c:2968
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x4c/0xa0 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(&mm->mmap_lock);
                               lock(&sb->s_type->i_mutex_key#13);
                               lock(&mm->mmap_lock);
  lock(&sb->s_type->i_mutex_key#13);

 *** DEADLOCK ***

1 lock held by syz.0.17/4429:
 #0: ffff88807bb83d58 (&mm->mmap_lock){++++}-{3:3}, at: mmap_write_lock_killable include/linux/mmap_lock.h:87 [inline]
 #0: ffff88807bb83d58 (&mm->mmap_lock){++++}-{3:3}, at: __do_sys_remap_file_pages mm/mmap.c:2993 [inline]
 #0: ffff88807bb83d58 (&mm->mmap_lock){++++}-{3:3}, at: __se_sys_remap_file_pages+0x17d/0x770 mm/mmap.c:2968

stack backtrace:
CPU: 1 PID: 4429 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106
 check_noncircular+0x274/0x310 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 kernel/locking/lockdep.c:3825 [inline]
 __lock_acquire+0x2cf8/0x7c50 kernel/locking/lockdep.c:5049
 lock_acquire+0x1b4/0x490 kernel/locking/lockdep.c:5662
 down_write+0x36/0x60 kernel/locking/rwsem.c:1573
 inode_lock include/linux/fs.h:758 [inline]
 process_measurement+0x33c/0x1a10 security/integrity/ima/ima_main.c:242
 ima_file_mmap+0x104/0x150 security/integrity/ima/ima_main.c:429
 __do_sys_remap_file_pages mm/mmap.c:3036 [inline]
 __se_sys_remap_file_pages+0x53e/0x770 mm/mmap.c:2968
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f149cb8f749
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:00007f149c1fe038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d8
RAX: ffffffffffffffda RBX: 00007f149cde5fa0 RCX: 00007f149cb8f749
RDX: 0000000000000000 RSI: 0000000000200000 RDI: 00002000002ec000
RBP: 00007f149cc13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f149cde6038 R14: 00007f149cde5fa0 R15: 00007ffd24559128
 </TASK>