[syzbot] [udf?] possible deadlock in mempool_alloc

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 0450d2083be6 Merge tag '6.10-rc-smb-fix' of git://git.samb..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=11281592980000
kernel config: https://syzkaller.appspot.com/x/.config?x=11eee78d9c5171fd
dashboard link: https://syzkaller.appspot.com/bug?extid=643b5ab661c7d54b7c84
compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: i386

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

Downloadable assets:
disk image (non-bootable): https://storage.googleapis.com/syzbot-assets/7bc7510fe41f/non_bootable_disk-0450d208.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/93488b2dd484/vmlinux-0450d208.xz
kernel image: https://storage.googleapis.com/syzbot-assets/86e4c49ad04d/bzImage-0450d208.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+643b5a...@syzkaller.appspotmail.com

Buffer I/O error on dev loop1, logical block 1434, async page read
Buffer I/O error on dev loop1, logical block 1435, async page read
======================================================
WARNING: possible circular locking dependency detected
6.9.0-syzkaller-08995-g0450d2083be6 #0 Not tainted
------------------------------------------------------
syz-executor.1/22245 is trying to acquire lock:
ffffffff8dd3a8c0 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:312 [inline]
ffffffff8dd3a8c0 (fs_reclaim){+.+.}-{0:0}, at: mempool_alloc+0xd9/0x390 mm/mempool.c:398

but task is already holding lock:
ffff888068818448 (mapping.invalidate_lock#11){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:846 [inline]
ffff888068818448 (mapping.invalidate_lock#11){++++}-{3:3}, at: filemap_fault+0x5cb/0x2630 mm/filemap.c:3296

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #1 (mapping.invalidate_lock#11){++++}-{3:3}:
down_write+0x3a/0x50 kernel/locking/rwsem.c:1579
filemap_invalidate_lock include/linux/fs.h:836 [inline]
udf_setsize+0x256/0x1180 fs/udf/inode.c:1254
udf_evict_inode+0x361/0x590 fs/udf/inode.c:144
evict+0x2ed/0x6c0 fs/inode.c:667
iput_final fs/inode.c:1741 [inline]
iput.part.0+0x5a8/0x7f0 fs/inode.c:1767
iput+0x5c/0x80 fs/inode.c:1757
dentry_unlink_inode+0x295/0x440 fs/dcache.c:400
__dentry_kill+0x1d0/0x600 fs/dcache.c:603
shrink_kill fs/dcache.c:1048 [inline]
shrink_dentry_list+0x140/0x5d0 fs/dcache.c:1075
prune_dcache_sb+0xeb/0x150 fs/dcache.c:1156
super_cache_scan+0x32a/0x550 fs/super.c:221
do_shrink_slab+0x44f/0x11c0 mm/shrinker.c:435
shrink_slab_memcg mm/shrinker.c:548 [inline]
shrink_slab+0xa87/0x1310 mm/shrinker.c:626
shrink_one+0x493/0x7c0 mm/vmscan.c:4774
shrink_many mm/vmscan.c:4835 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4935
shrink_node mm/vmscan.c:5894 [inline]
kswapd_shrink_node mm/vmscan.c:6704 [inline]
balance_pgdat+0x10d1/0x1a10 mm/vmscan.c:6895
kswapd+0x5ea/0xbf0 mm/vmscan.c:7164
kthread+0x2c1/0x3a0 kernel/kthread.c:389
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

-> #0 (fs_reclaim){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
__fs_reclaim_acquire mm/page_alloc.c:3698 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3712
might_alloc include/linux/sched/mm.h:312 [inline]
mempool_alloc+0xd9/0x390 mm/mempool.c:398
bio_alloc_bioset+0x480/0x8b0 block/bio.c:554
bio_alloc include/linux/bio.h:437 [inline]
do_mpage_readpage+0xf30/0x17c0 fs/mpage.c:297
mpage_read_folio+0xa9/0x140 fs/mpage.c:399
udf_read_folio+0x8b/0xe0 fs/udf/inode.c:235
filemap_read_folio+0xe5/0x2c0 mm/filemap.c:2331
filemap_fault+0x1458/0x2630 mm/filemap.c:3381
__do_fault+0x10a/0x490 mm/memory.c:4526
do_read_fault mm/memory.c:4889 [inline]
do_fault mm/memory.c:5019 [inline]
do_pte_missing mm/memory.c:3875 [inline]
handle_pte_fault mm/memory.c:5295 [inline]
__handle_mm_fault+0x371d/0x4a80 mm/memory.c:5436
handle_mm_fault+0x476/0xa00 mm/memory.c:5601
do_user_addr_fault+0x2e5/0x1010 arch/x86/mm/fault.c:1383
handle_page_fault arch/x86/mm/fault.c:1475 [inline]
exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1533
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline]
raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline]
_copy_from_user+0xc1/0xf0 lib/usercopy.c:23
copy_from_user include/linux/uaccess.h:183 [inline]
copy_from_bpfptr_offset include/linux/bpfptr.h:53 [inline]
copy_from_bpfptr include/linux/bpfptr.h:59 [inline]
__sys_bpf+0x22b/0x58f0 kernel/bpf/syscall.c:5660
__do_sys_bpf kernel/bpf/syscall.c:5794 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5792 [inline]
__ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5792
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
rlock(mapping.invalidate_lock#11);
lock(fs_reclaim);
lock(mapping.invalidate_lock#11);
lock(fs_reclaim);

*** DEADLOCK ***

1 lock held by syz-executor.1/22245:
#0: ffff888068818448 (mapping.invalidate_lock#11){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:846 [inline]
#0: ffff888068818448 (mapping.invalidate_lock#11){++++}-{3:3}, at: filemap_fault+0x5cb/0x2630 mm/filemap.c:3296

stack backtrace:
CPU: 3 PID: 22245 Comm: syz-executor.1 Not tainted 6.9.0-syzkaller-08995-g0450d2083be6 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:114
check_noncircular+0x31a/0x400 kernel/locking/lockdep.c:2187
check_prev_add kernel/locking/lockdep.c:3134 [inline]
check_prevs_add kernel/locking/lockdep.c:3253 [inline]
validate_chain kernel/locking/lockdep.c:3869 [inline]
__lock_acquire+0x2478/0x3b30 kernel/locking/lockdep.c:5137
lock_acquire kernel/locking/lockdep.c:5754 [inline]
lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5719
__fs_reclaim_acquire mm/page_alloc.c:3698 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3712
might_alloc include/linux/sched/mm.h:312 [inline]
mempool_alloc+0xd9/0x390 mm/mempool.c:398
bio_alloc_bioset+0x480/0x8b0 block/bio.c:554
bio_alloc include/linux/bio.h:437 [inline]
do_mpage_readpage+0xf30/0x17c0 fs/mpage.c:297
mpage_read_folio+0xa9/0x140 fs/mpage.c:399
udf_read_folio+0x8b/0xe0 fs/udf/inode.c:235
filemap_read_folio+0xe5/0x2c0 mm/filemap.c:2331
filemap_fault+0x1458/0x2630 mm/filemap.c:3381
__do_fault+0x10a/0x490 mm/memory.c:4526
do_read_fault mm/memory.c:4889 [inline]
do_fault mm/memory.c:5019 [inline]
do_pte_missing mm/memory.c:3875 [inline]
handle_pte_fault mm/memory.c:5295 [inline]
__handle_mm_fault+0x371d/0x4a80 mm/memory.c:5436
handle_mm_fault+0x476/0xa00 mm/memory.c:5601
do_user_addr_fault+0x2e5/0x1010 arch/x86/mm/fault.c:1383
handle_page_fault arch/x86/mm/fault.c:1475 [inline]
exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1533
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:110 [inline]
RIP: 0010:raw_copy_from_user arch/x86/include/asm/uaccess_64.h:125 [inline]
RIP: 0010:_copy_from_user+0xc1/0xf0 lib/usercopy.c:23
Code: 89 df e8 f2 ea 0e fd 4d 85 f6 75 9e e8 98 f0 0e fd 0f ae e8 89 ee 4c 89 ef e8 2b 33 6c fd 0f 01 cb 48 89 e9 4c 89 ef 48 89 de <f3> a4 0f 1f 00 48 89 cb 0f 01 ca e9 73 ff ff ff e8 6a f0 0e fd 48
RSP: 0018:ffffc9000425fc10 EFLAGS: 00050246
RAX: 0000000000000001 RBX: 0000000020000540 RCX: 0000000000000020
RDX: fffff5200084bfba RSI: 0000000020000540 RDI: ffffc9000425fdb0
RBP: 0000000000000020 R08: 0000000000000001 R09: fffff5200084bfb9
R10: ffffc9000425fdcf R11: 0000000000000000 R12: 0000000020000560
R13: ffffc9000425fdb0 R14: 0000000000000000 R15: ffffc9000425fdb0
copy_from_user include/linux/uaccess.h:183 [inline]
copy_from_bpfptr_offset include/linux/bpfptr.h:53 [inline]
copy_from_bpfptr include/linux/bpfptr.h:59 [inline]
__sys_bpf+0x22b/0x58f0 kernel/bpf/syscall.c:5660
__do_sys_bpf kernel/bpf/syscall.c:5794 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5792 [inline]
__ia32_sys_bpf+0x76/0xe0 kernel/bpf/syscall.c:5792
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x75/0x120 arch/x86/entry/common.c:386
do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf72f9579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f5eeb5ac EFLAGS: 00000292 ORIG_RAX: 0000000000000165
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000020000540
RDX: 0000000000000020 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
----------------
Code disassembly (best guess):
0: 89 df mov %ebx,%edi
2: e8 f2 ea 0e fd call 0xfd0eeaf9
7: 4d 85 f6 test %r14,%r14
a: 75 9e jne 0xffffffaa
c: e8 98 f0 0e fd call 0xfd0ef0a9
11: 0f ae e8 lfence
14: 89 ee mov %ebp,%esi
16: 4c 89 ef mov %r13,%rdi
19: e8 2b 33 6c fd call 0xfd6c3349
1e: 0f 01 cb stac
21: 48 89 e9 mov %rbp,%rcx
24: 4c 89 ef mov %r13,%rdi
27: 48 89 de mov %rbx,%rsi
* 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction
2c: 0f 1f 00 nopl (%rax)
2f: 48 89 cb mov %rcx,%rbx
32: 0f 01 ca clac
35: e9 73 ff ff ff jmp 0xffffffad
3a: e8 6a f0 0e fd call 0xfd0ef0a9
3f: 48 rex.W


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