[syzbot] [ocfs2?] possible deadlock in ocfs2_read_folio

[syzbot <syzbot+bd316bb736c7dc2f318e@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    9946eaf552b1 Merge tag 'hardening-v6.14-rc2' of git://git...
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=165382a4580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=147b7d49d83b8036
dashboard link: https://syzkaller.appspot.com/bug?extid=bd316bb736c7dc2f318e
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/eac613b48ce8/disk-9946eaf5.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a9e51f9c7777/vmlinux-9946eaf5.xz
kernel image: https://storage.googleapis.com/syzbot-assets/96f75428ab6a/bzImage-9946eaf5.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+bd316bb736c7dc2f318e@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc1-syzkaller-00235-g9946eaf552b1 #0 Not tainted
------------------------------------------------------
syz.2.361/9103 is trying to acquire lock:
ffff88807fd822e0 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}, at: ocfs2_read_folio+0x36a/0x980 fs/ocfs2/aops.c:294

but task is already holding lock:
ffff88807fd827e0 (mapping.invalidate_lock#13){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
ffff88807fd827e0 (mapping.invalidate_lock#13){.+.+}-{4:4}, at: filemap_create_folio mm/filemap.c:2516 [inline]
ffff88807fd827e0 (mapping.invalidate_lock#13){.+.+}-{4:4}, at: filemap_get_pages+0xdc3/0x1fb0 mm/filemap.c:2586

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (mapping.invalidate_lock#13){.+.+}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
       filemap_fault+0x7f8/0x16c0 mm/filemap.c:3435
       ocfs2_fault+0xbb/0x3d0 fs/ocfs2/mmap.c:38
       __do_fault+0x135/0x390 mm/memory.c:4977
       do_read_fault mm/memory.c:5392 [inline]
       do_fault mm/memory.c:5526 [inline]
       do_pte_missing mm/memory.c:4047 [inline]
       handle_pte_fault mm/memory.c:5889 [inline]
       __handle_mm_fault+0x4c44/0x70f0 mm/memory.c:6032
       handle_mm_fault+0x2c1/0x7e0 mm/memory.c:6201
       do_user_addr_fault arch/x86/mm/fault.c:1388 [inline]
       handle_page_fault arch/x86/mm/fault.c:1480 [inline]
       exc_page_fault+0x2b9/0x8b0 arch/x86/mm/fault.c:1538
       asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623

-> #1 (&mm->mmap_lock){++++}-{4:4}:
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       __might_fault+0xc6/0x120 mm/memory.c:6840
       _inline_copy_to_user include/linux/uaccess.h:192 [inline]
       _copy_to_user+0x2c/0xb0 lib/usercopy.c:26
       copy_to_user include/linux/uaccess.h:225 [inline]
       fiemap_fill_next_extent+0x235/0x410 fs/ioctl.c:145
       ocfs2_fiemap+0x9f1/0xf80 fs/ocfs2/extent_map.c:806
       ioctl_fiemap fs/ioctl.c:220 [inline]
       do_vfs_ioctl+0x1c01/0x2e40 fs/ioctl.c:840
       __do_sys_ioctl fs/ioctl.c:904 [inline]
       __se_sys_ioctl+0x80/0x170 fs/ioctl.c:892
       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 (&ocfs2_file_ip_alloc_sem_key){++++}-{4:4}:
       check_prev_add kernel/locking/lockdep.c:3163 [inline]
       check_prevs_add kernel/locking/lockdep.c:3282 [inline]
       validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
       __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
       lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
       down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
       ocfs2_read_folio+0x36a/0x980 fs/ocfs2/aops.c:294
       filemap_read_folio+0x148/0x3b0 mm/filemap.c:2390
       filemap_create_folio mm/filemap.c:2525 [inline]
       filemap_get_pages+0x1042/0x1fb0 mm/filemap.c:2586
       filemap_splice_read+0x68e/0xef0 mm/filemap.c:2971
       do_splice_read fs/splice.c:985 [inline]
       splice_direct_to_actor+0x4af/0xc80 fs/splice.c:1089
       do_splice_direct_actor fs/splice.c:1207 [inline]
       do_splice_direct+0x289/0x3e0 fs/splice.c:1233
       do_sendfile+0x564/0x8a0 fs/read_write.c:1363
       __do_sys_sendfile64 fs/read_write.c:1424 [inline]
       __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1410
       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:

Chain exists of:
  &ocfs2_file_ip_alloc_sem_key --> &mm->mmap_lock --> mapping.invalidate_lock#13

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  rlock(mapping.invalidate_lock#13);
                               lock(&mm->mmap_lock);
                               lock(mapping.invalidate_lock#13);
  rlock(&ocfs2_file_ip_alloc_sem_key);

 *** DEADLOCK ***

1 lock held by syz.2.361/9103:
 #0: ffff88807fd827e0 (mapping.invalidate_lock#13){.+.+}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:932 [inline]
 #0: ffff88807fd827e0 (mapping.invalidate_lock#13){.+.+}-{4:4}, at: filemap_create_folio mm/filemap.c:2516 [inline]
 #0: ffff88807fd827e0 (mapping.invalidate_lock#13){.+.+}-{4:4}, at: filemap_get_pages+0xdc3/0x1fb0 mm/filemap.c:2586

stack backtrace:
CPU: 0 UID: 0 PID: 9103 Comm: syz.2.361 Not tainted 6.14.0-rc1-syzkaller-00235-g9946eaf552b1 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
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:2076
 check_noncircular+0x36a/0x4a0 kernel/locking/lockdep.c:2208
 check_prev_add kernel/locking/lockdep.c:3163 [inline]
 check_prevs_add kernel/locking/lockdep.c:3282 [inline]
 validate_chain+0x18ef/0x5920 kernel/locking/lockdep.c:3906
 __lock_acquire+0x1397/0x2100 kernel/locking/lockdep.c:5228
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5851
 down_read+0xb1/0xa40 kernel/locking/rwsem.c:1524
 ocfs2_read_folio+0x36a/0x980 fs/ocfs2/aops.c:294
 filemap_read_folio+0x148/0x3b0 mm/filemap.c:2390
 filemap_create_folio mm/filemap.c:2525 [inline]
 filemap_get_pages+0x1042/0x1fb0 mm/filemap.c:2586
 filemap_splice_read+0x68e/0xef0 mm/filemap.c:2971
 do_splice_read fs/splice.c:985 [inline]
 splice_direct_to_actor+0x4af/0xc80 fs/splice.c:1089
 do_splice_direct_actor fs/splice.c:1207 [inline]
 do_splice_direct+0x289/0x3e0 fs/splice.c:1233
 do_sendfile+0x564/0x8a0 fs/read_write.c:1363
 __do_sys_sendfile64 fs/read_write.c:1424 [inline]
 __se_sys_sendfile64+0x17c/0x1e0 fs/read_write.c:1410
 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: 0033:0x7f943158cde9
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:00007f9432389038 EFLAGS: 00000246 ORIG_RAX: 0000000000000028
RAX: ffffffffffffffda RBX: 00007f94317a6080 RCX: 00007f943158cde9
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000008
RBP: 00007f943160e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000fffe83 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f94317a6080 R15: 00007ffd6d546fb8
 </TASK>


---
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