[syzbot] [reiserfs?] possible deadlock in reiserfs_get_block

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: f9ff5644bcc0 Merge tag 'hsi-for-6.2' of git://git.kernel.o..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1246ddbf880000
kernel config: https://syzkaller.appspot.com/x/.config?x=c163713cf9186fe7
dashboard link: https://syzkaller.appspot.com/bug?extid=8a4c84020c63609f15ec
compiler: Debian clang version 13.0.1-++20220126092033+75e33f71c2da-1~exp1~20220126212112.63, GNU ld (GNU Binutils for Debian) 2.35.2

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/95eb66f6b569/disk-f9ff5644.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/fb05e1a5a9de/vmlinux-f9ff5644.xz
kernel image: https://storage.googleapis.com/syzbot-assets/e2f1f698973a/bzImage-f9ff5644.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8a4c84...@syzkaller.appspotmail.com

REISERFS (device loop2): Created .reiserfs_priv - reserved for xattr storage.
======================================================
WARNING: possible circular locking dependency detected
6.1.0-syzkaller-13139-gf9ff5644bcc0 #0 Not tainted
------------------------------------------------------
syz-executor.2/16192 is trying to acquire lock:
ffff8880220f5018 (&mm->mmap_lock#2){++++}-{3:3}, at: __might_fault+0x8f/0x110 mm/memory.c:5646

but task is already holding lock:
ffff88801f15e090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x77/0xd0 fs/reiserfs/lock.c:27

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #2 (&sbi->lock){+.+.}-{3:3}:
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
__mutex_lock_common+0x1bd/0x26e0 kernel/locking/mutex.c:603
__mutex_lock kernel/locking/mutex.c:747 [inline]
mutex_lock_nested+0x17/0x20 kernel/locking/mutex.c:799
reiserfs_write_lock+0x77/0xd0 fs/reiserfs/lock.c:27
reiserfs_get_block+0x24e/0x5180 fs/reiserfs/inode.c:680
do_mpage_readpage+0x970/0x1c50 fs/mpage.c:208
mpage_readahead+0x210/0x380 fs/mpage.c:361
read_pages+0x169/0x9c0 mm/readahead.c:161
page_cache_ra_unbounded+0x194/0x820 mm/readahead.c:242
page_cache_sync_readahead include/linux/pagemap.h:1210 [inline]
filemap_get_pages+0x465/0x10d0 mm/filemap.c:2600
filemap_read+0x3cf/0xea0 mm/filemap.c:2694
call_read_iter include/linux/fs.h:2180 [inline]
generic_file_splice_read+0x1ff/0x5d0 fs/splice.c:309
do_splice_to fs/splice.c:793 [inline]
splice_direct_to_actor+0x41b/0xc00 fs/splice.c:865
do_splice_direct+0x279/0x3d0 fs/splice.c:974
do_sendfile+0x5fb/0xf80 fs/read_write.c:1255
__do_sys_sendfile64 fs/read_write.c:1323 [inline]
__se_sys_sendfile64+0x14f/0x1b0 fs/read_write.c:1309
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

-> #1 (mapping.invalidate_lock#7){.+.+}-{3:3}:
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
down_read+0x39/0x50 kernel/locking/rwsem.c:1509
filemap_invalidate_lock_shared include/linux/fs.h:811 [inline]
filemap_fault+0x2fb/0x1060 mm/filemap.c:3146
__do_fault+0x136/0x4f0 mm/memory.c:4163
do_shared_fault mm/memory.c:4569 [inline]
do_fault mm/memory.c:4647 [inline]
handle_pte_fault mm/memory.c:4931 [inline]
__handle_mm_fault mm/memory.c:5073 [inline]
handle_mm_fault+0x17fa/0x2640 mm/memory.c:5219
do_user_addr_fault+0x69b/0xcb0 arch/x86/mm/fault.c:1428
handle_page_fault arch/x86/mm/fault.c:1519 [inline]
exc_page_fault+0x7a/0x110 arch/x86/mm/fault.c:1575
asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

-> #0 (&mm->mmap_lock#2){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
__lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
__might_fault+0xb2/0x110 mm/memory.c:5647
reiserfs_ioctl+0x11c/0x340 fs/reiserfs/ioctl.c:96
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Chain exists of:
&mm->mmap_lock#2 --> mapping.invalidate_lock#7 --> &sbi->lock

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&sbi->lock);
lock(mapping.invalidate_lock#7);
lock(&sbi->lock);
lock(&mm->mmap_lock#2);

*** DEADLOCK ***

1 lock held by syz-executor.2/16192:
#0: ffff88801f15e090 (&sbi->lock){+.+.}-{3:3}, at: reiserfs_write_lock+0x77/0xd0 fs/reiserfs/lock.c:27

stack backtrace:
CPU: 0 PID: 16192 Comm: syz-executor.2 Not tainted 6.1.0-syzkaller-13139-gf9ff5644bcc0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1b1/0x290 lib/dump_stack.c:106
check_noncircular+0x2cc/0x390 kernel/locking/lockdep.c:2177
check_prev_add kernel/locking/lockdep.c:3097 [inline]
check_prevs_add kernel/locking/lockdep.c:3216 [inline]
validate_chain+0x1898/0x6ae0 kernel/locking/lockdep.c:3831
__lock_acquire+0x1292/0x1f60 kernel/locking/lockdep.c:5055
lock_acquire+0x182/0x3c0 kernel/locking/lockdep.c:5668
__might_fault+0xb2/0x110 mm/memory.c:5647
reiserfs_ioctl+0x11c/0x340 fs/reiserfs/ioctl.c:96
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:870 [inline]
__se_sys_ioctl+0xfb/0x170 fs/ioctl.c:856
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5a8b88c0d9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5a8c578168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5a8b9abf80 RCX: 00007f5a8b88c0d9
RDX: 00000000200000c0 RSI: 0000000080087601 RDI: 0000000000000004
RBP: 00007f5a8b8e7ae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff6e17e56f R14: 00007f5a8c578300 R15: 0000000000022000
</TASK>


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.