syzbot
WARNING: locking bug in __refill_objects_node
Status:
upstream: reported C repro on 2026/10/26 10:19
Subsystems:
kvm
Labels:
prio:high
[Documentation on labels]
Reported-by: syzbot+f11512d1e5878ba5e60e@syzkaller.appspotmail.com
First crash: 10d, last: 7d01h
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Last patch testing requests (1)
Sample crash report:
=============================
[ BUG: Invalid wait context ]
syzkaller #0 Tainted: G S
-----------------------------
syz-executor177/6041 is trying to lock:
ffff88801d040618 (&n->list_lock){-.-.}-{3:3}, at: get_partial_node_bulk mm/slub.c:3831 [inline]
ffff88801d040618 (&n->list_lock){-.-.}-{3:3}, at: __refill_objects_node+0x104/0xab0 mm/slub.c:7279
other info that might help us debug this:
context-{2:2}
locks held by syz-executor177/6041: 1, last CPU#1:
#0: ffffffff9090b438 (tomoyo_ss){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:198 [inline]
#0: ffffffff9090b438 (tomoyo_ss){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:305 [inline]
#0: ffffffff9090b438 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_read_lock security/tomoyo/common.h:1112 [inline]
#0: ffffffff9090b438 (tomoyo_ss){.+.+}-{0:0}, at: tomoyo_check_open_permission+0x169/0x3c0 security/tomoyo/file.c:772
stack backtrace:
CPU: 1 UID: 0 PID: 6041 Comm: syz-executor177 Tainted: G S syzkaller #0 PREEMPT(full)
Tainted: [S]=CPU_OUT_OF_SPEC
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120
print_lock_invalid_wait_context kernel/locking/lockdep.c:4874 [inline]
check_wait_context kernel/locking/lockdep.c:4946 [inline]
__lock_acquire+0xfcc/0x1f40 kernel/locking/lockdep.c:5238
lock_acquire kernel/locking/lockdep.c:5942 [inline]
lock_acquire+0x1d1/0x380 kernel/locking/lockdep.c:5899
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:155 [inline]
_raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:181
get_partial_node_bulk mm/slub.c:3831 [inline]
__refill_objects_node+0x104/0xab0 mm/slub.c:7279
refill_objects+0x58/0x410 mm/slub.c:7405
refill_sheaf mm/slub.c:2885 [inline]
__pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774
alloc_from_pcs mm/slub.c:4850 [inline]
slab_alloc_node mm/slub.c:4984 [inline]
__kmalloc_cache_noprof+0x4f4/0x6d0 mm/slub.c:5559
_kmalloc_noprof include/linux/slab.h:991 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
kvm_async_pf_task_wake arch/x86/kernel/kvm.c:224 [inline]
__sysvec_kvm_asyncpf_interrupt+0x334/0x610 arch/x86/kernel/kvm.c:338
instr_sysvec_kvm_asyncpf_interrupt arch/x86/kernel/kvm.c:327 [inline]
sysvec_kvm_asyncpf_interrupt+0x9e/0xc0 arch/x86/kernel/kvm.c:327
</IRQ>
<TASK>
asm_sysvec_kvm_asyncpf_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:753
RIP: 0010:memcmp+0x156/0x1d0 lib/string.c:665
Code: 0f 86 fb fe ff ff 48 89 d8 48 89 de 48 c1 e8 03 83 e6 07 42 0f b6 14 28 48 8d 43 07 48 89 c1 48 c1 e9 03 40 38 f2 40 0f 9e c6 <84> d2 42 0f b6 0c 29 0f 95 c2 40 84 d6 0f 84 45 ff ff ff be 08 00
RSP: 0018:ffffc90003ab7538 EFLAGS: 00000297
RAX: ffff8880220be413 RBX: ffff8880220be40c RCX: 1ffff11004417c82
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8880220be40c
RBP: ffffffff8c58a940 R08: 0000000000000001 R09: 0000000000000066
R10: 0000000000000066 R11: 0000000000000001 R12: 0000000000000012
R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000000
strstr+0x109/0x170 lib/string.c:743
tomoyo_add_entry security/tomoyo/common.c:2157 [inline]
tomoyo_supervisor+0xf47/0x1340 security/tomoyo/common.c:2238
tomoyo_audit_path_log security/tomoyo/file.c:169 [inline]
tomoyo_path_permission security/tomoyo/file.c:592 [inline]
tomoyo_path_permission+0x270/0x3b0 security/tomoyo/file.c:577
tomoyo_check_open_permission+0x37f/0x3c0 security/tomoyo/file.c:782
tomoyo_file_open+0x6b/0x90 security/tomoyo/tomoyo.c:334
security_file_open+0xb5/0x1e0 security/security.c:2739
do_dentry_open+0x588/0x14d0 fs/open.c:973
vfs_open+0x82/0x3f0 fs/open.c:1101
do_open fs/namei.c:4836 [inline]
path_openat+0x1a23/0x2450 fs/namei.c:4999
do_file_open+0x20e/0x430 fs/namei.c:5028
do_sys_openat2+0x10f/0x1e0 fs/open.c:1417
do_sys_open fs/open.c:1423 [inline]
__do_sys_openat fs/open.c:1439 [inline]
__se_sys_openat fs/open.c:1434 [inline]
__x64_sys_openat+0x12d/0x210 fs/open.c:1434
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f589f9da7be
Code: 08 0f 85 55 ec ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 <c3> 90 41 57 41 56 4d 89 c6 41 55 4d 89 cd 41 54 55 53 48 83 ec 08
RSP: 002b:00007f589affe098 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f589affe6c0 RCX: 00007f589f9da7be
RDX: 0000000000000002 RSI: 00007f589affe1a0 RDI: ffffffffffffff9c
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f589affe1a0
R13: 0000000000000001 R14: 00007ffef59973a0 R15: 00007ffef5997488
</TASK>
----------------
Code disassembly (best guess):
0: 0f 86 fb fe ff ff jbe 0xffffff01
6: 48 89 d8 mov %rbx,%rax
9: 48 89 de mov %rbx,%rsi
c: 48 c1 e8 03 shr $0x3,%rax
10: 83 e6 07 and $0x7,%esi
13: 42 0f b6 14 28 movzbl (%rax,%r13,1),%edx
18: 48 8d 43 07 lea 0x7(%rbx),%rax
1c: 48 89 c1 mov %rax,%rcx
1f: 48 c1 e9 03 shr $0x3,%rcx
23: 40 38 f2 cmp %sil,%dl
26: 40 0f 9e c6 setle %sil
* 2a: 84 d2 test %dl,%dl <-- trapping instruction
2c: 42 0f b6 0c 29 movzbl (%rcx,%r13,1),%ecx
31: 0f 95 c2 setne %dl
34: 40 84 d6 test %dl,%sil
37: 0f 84 45 ff ff ff je 0xffffff82
3d: be .byte 0xbe
3e: 08 00 or %al,(%rax)
* Struck through repros no longer work on HEAD.