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Message-ID: <000000000000565ec5061bdeafd5@google.com>
Date: Thu, 27 Jun 2024 05:58:18 -0700
From: syzbot <syzbot+df3558df41609451e4ac@...kaller.appspotmail.com>
To: linkinjeon@...nel.org, linux-fsdevel@...r.kernel.org,
linux-kernel@...r.kernel.org, sj1557.seo@...sung.com,
syzkaller-bugs@...glegroups.com
Subject: [syzbot] [exfat?] possible deadlock in exfat_iterate (2)
Hello,
syzbot found the following issue on:
HEAD commit: 55027e689933 Merge tag 'input-for-v6.10-rc5' of git://git...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16390ac1980000
kernel config: https://syzkaller.appspot.com/x/.config?x=53ab35b556129242
dashboard link: https://syzkaller.appspot.com/bug?extid=df3558df41609451e4ac
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-55027e68.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a36929b5a065/vmlinux-55027e68.xz
kernel image: https://storage.googleapis.com/syzbot-assets/d72de6f61ddc/bzImage-55027e68.xz
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+df3558df41609451e4ac@...kaller.appspotmail.com
======================================================
WARNING: possible circular locking dependency detected
6.10.0-rc5-syzkaller-00018-g55027e689933 #0 Not tainted
------------------------------------------------------
syz-executor.2/6265 is trying to acquire lock:
ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: might_alloc include/linux/sched/mm.h:334 [inline]
ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: slab_pre_alloc_hook mm/slub.c:3891 [inline]
ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: slab_alloc_node mm/slub.c:3981 [inline]
ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: __do_kmalloc_node mm/slub.c:4121 [inline]
ffffffff8dd3ab20 (fs_reclaim){+.+.}-{0:0}, at: __kmalloc_noprof+0xb5/0x420 mm/slub.c:4135
but task is already holding lock:
ffff88804af1a0e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_iterate+0x33f/0xad0 fs/exfat/dir.c:256
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&sbi->s_lock#2){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:608 [inline]
__mutex_lock+0x175/0x9c0 kernel/locking/mutex.c:752
exfat_evict_inode+0x25b/0x340 fs/exfat/inode.c:725
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+0x295/0x480 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:4790
shrink_many mm/vmscan.c:4851 [inline]
lru_gen_shrink_node+0x89f/0x1750 mm/vmscan.c:4951
shrink_node mm/vmscan.c:5910 [inline]
kswapd_shrink_node mm/vmscan.c:6720 [inline]
balance_pgdat+0x1105/0x1970 mm/vmscan.c:6911
kswapd+0x5ea/0xbf0 mm/vmscan.c:7180
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:3801 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815
might_alloc include/linux/sched/mm.h:334 [inline]
slab_pre_alloc_hook mm/slub.c:3891 [inline]
slab_alloc_node mm/slub.c:3981 [inline]
__do_kmalloc_node mm/slub.c:4121 [inline]
__kmalloc_noprof+0xb5/0x420 mm/slub.c:4135
kmalloc_noprof include/linux/slab.h:664 [inline]
kmalloc_array_noprof include/linux/slab.h:699 [inline]
__exfat_get_dentry_set+0x81e/0xa90 fs/exfat/dir.c:816
exfat_get_dentry_set+0x36/0x210 fs/exfat/dir.c:859
exfat_get_uniname_from_ext_entry fs/exfat/dir.c:39 [inline]
exfat_readdir+0x950/0x1520 fs/exfat/dir.c:155
exfat_iterate+0x3c7/0xad0 fs/exfat/dir.c:261
wrap_directory_iterator+0xa5/0xe0 fs/readdir.c:67
iterate_dir+0x53e/0xb60 fs/readdir.c:110
__do_sys_getdents64 fs/readdir.c:409 [inline]
__se_sys_getdents64 fs/readdir.c:394 [inline]
__ia32_sys_getdents64+0x14f/0x2e0 fs/readdir.c:394
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 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
---- ----
lock(&sbi->s_lock#2);
lock(fs_reclaim);
lock(&sbi->s_lock#2);
lock(fs_reclaim);
*** DEADLOCK ***
3 locks held by syz-executor.2/6265:
#0: ffff88801db114c8 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xeb/0x180 fs/file.c:1191
#1: ffff8880483da9e8 (&sb->s_type->i_mutex_key#24){++++}-{3:3}, at: wrap_directory_iterator+0x5a/0xe0 fs/readdir.c:56
#2: ffff88804af1a0e0 (&sbi->s_lock#2){+.+.}-{3:3}, at: exfat_iterate+0x33f/0xad0 fs/exfat/dir.c:256
stack backtrace:
CPU: 0 PID: 6265 Comm: syz-executor.2 Not tainted 6.10.0-rc5-syzkaller-00018-g55027e689933 #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:3801 [inline]
fs_reclaim_acquire+0x102/0x160 mm/page_alloc.c:3815
might_alloc include/linux/sched/mm.h:334 [inline]
slab_pre_alloc_hook mm/slub.c:3891 [inline]
slab_alloc_node mm/slub.c:3981 [inline]
__do_kmalloc_node mm/slub.c:4121 [inline]
__kmalloc_noprof+0xb5/0x420 mm/slub.c:4135
kmalloc_noprof include/linux/slab.h:664 [inline]
kmalloc_array_noprof include/linux/slab.h:699 [inline]
__exfat_get_dentry_set+0x81e/0xa90 fs/exfat/dir.c:816
exfat_get_dentry_set+0x36/0x210 fs/exfat/dir.c:859
exfat_get_uniname_from_ext_entry fs/exfat/dir.c:39 [inline]
exfat_readdir+0x950/0x1520 fs/exfat/dir.c:155
exfat_iterate+0x3c7/0xad0 fs/exfat/dir.c:261
wrap_directory_iterator+0xa5/0xe0 fs/readdir.c:67
iterate_dir+0x53e/0xb60 fs/readdir.c:110
__do_sys_getdents64 fs/readdir.c:409 [inline]
__se_sys_getdents64 fs/readdir.c:394 [inline]
__ia32_sys_getdents64+0x14f/0x2e0 fs/readdir.c:394
do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
__do_fast_syscall_32+0x73/0x120 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: 0023:0xf72f8579
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:00000000f5ec95ac EFLAGS: 00000292 ORIG_RAX: 00000000000000dc
RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000020002ec0
RDX: 0000000000001000 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), 2 bytes skipped:
0: 10 06 adc %al,(%rsi)
2: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
6: 10 07 adc %al,(%rdi)
8: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
c: 10 08 adc %cl,(%rax)
e: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1e: 00 51 52 add %dl,0x52(%rcx)
21: 55 push %rbp
22: 89 e5 mov %esp,%ebp
24: 0f 34 sysenter
26: cd 80 int $0x80
* 28: 5d pop %rbp <-- trapping instruction
29: 5a pop %rdx
2a: 59 pop %rcx
2b: c3 ret
2c: 90 nop
2d: 90 nop
2e: 90 nop
2f: 90 nop
30: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
---
This report is generated by a bot. It may contain errors.
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