======================================================
WARNING: possible circular locking dependency detected
6.14.0-rc4-syzkaller-00073-g5394eea10651 #0 Not tainted
------------------------------------------------------
syz.0.465/7042 is trying to acquire lock:
ffff88803f6943c8 (&htab->lockdep_key#448){....}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:167 [inline]
ffff88803f6943c8 (&htab->lockdep_key#448){....}-{2:2}, at: htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1483
but task is already holding lock:
ffff88804a89d338 (&htab->lockdep_key#449){....}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:167 [inline]
ffff88804a89d338 (&htab->lockdep_key#449){....}-{2:2}, at: htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1483
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (&htab->lockdep_key#449){....}-{2:2}:
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
htab_lock_bucket kernel/bpf/hashtab.c:167 [inline]
htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1483
bpf_prog_6f5f05285f674219+0x43/0x4c
bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
__bpf_prog_run include/linux/filter.h:701 [inline]
bpf_prog_run include/linux/filter.h:708 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline]
bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2412
__bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95
__traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95
__preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline]
class_preempt_notrace_destructor include/linux/preempt.h:481 [inline]
__do_trace_contention_begin include/trace/events/lock.h:95 [inline]
trace_contention_begin.constprop.0+0xf3/0x170 include/trace/events/lock.h:95
__pv_queued_spin_lock_slowpath+0x10b/0xc90 kernel/locking/qspinlock.c:402
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:577 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x210/0x2c0 kernel/locking/spinlock_debug.c:116
htab_lock_bucket kernel/bpf/hashtab.c:167 [inline]
htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1483
bpf_prog_6f5f05285f674219+0x43/0x4c
bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
__bpf_prog_run include/linux/filter.h:701 [inline]
bpf_prog_run include/linux/filter.h:708 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline]
bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2412
__bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95
__traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95
__do_trace_contention_begin include/trace/events/lock.h:95 [inline]
trace_contention_begin+0xd2/0x140 include/trace/events/lock.h:95
__mutex_lock_common kernel/locking/mutex.c:587 [inline]
__mutex_lock+0x1a8/0xb10 kernel/locking/mutex.c:730
__set_oom_adj.isra.0+0x68/0x1120 fs/proc/base.c:1129
oom_score_adj_write+0x1b8/0x200 fs/proc/base.c:1294
vfs_write+0x24c/0x1150 fs/read_write.c:677
ksys_write+0x12b/0x250 fs/read_write.c:731
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&htab->lockdep_key#448){....}-{2:2}:
check_prev_add kernel/locking/lockdep.c:3163 [inline]
check_prevs_add kernel/locking/lockdep.c:3282 [inline]
validate_chain kernel/locking/lockdep.c:3906 [inline]
__lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
htab_lock_bucket kernel/bpf/hashtab.c:167 [inline]
htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1483
bpf_prog_6f5f05285f674219+0x43/0x4c
bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
__bpf_prog_run include/linux/filter.h:701 [inline]
bpf_prog_run include/linux/filter.h:708 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline]
bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2412
__bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95
__traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95
__preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline]
class_preempt_notrace_destructor include/linux/preempt.h:481 [inline]
__do_trace_contention_begin include/trace/events/lock.h:95 [inline]
trace_contention_begin.constprop.0+0xf3/0x170 include/trace/events/lock.h:95
__pv_queued_spin_lock_slowpath+0x10b/0xc90 kernel/locking/qspinlock.c:402
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:577 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x210/0x2c0 kernel/locking/spinlock_debug.c:116
htab_lock_bucket kernel/bpf/hashtab.c:167 [inline]
htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1483
bpf_prog_6f5f05285f674219+0x43/0x4c
bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
__bpf_prog_run include/linux/filter.h:701 [inline]
bpf_prog_run include/linux/filter.h:708 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline]
bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2412
__bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95
__traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95
__do_trace_contention_begin include/trace/events/lock.h:95 [inline]
trace_contention_begin+0xd2/0x140 include/trace/events/lock.h:95
__mutex_lock_common kernel/locking/mutex.c:587 [inline]
__mutex_lock+0x1a8/0xb10 kernel/locking/mutex.c:730
pcpu_alloc_noprof+0xc5a/0x1680 mm/percpu.c:1782
bpf_map_alloc_percpu+0x9a/0x4b0 kernel/bpf/syscall.c:555
prealloc_init kernel/bpf/hashtab.c:341 [inline]
htab_map_alloc+0x1231/0x17b0 kernel/bpf/hashtab.c:579
map_create+0x5c5/0x1d20 kernel/bpf/syscall.c:1455
__sys_bpf+0x4391/0x49c0 kernel/bpf/syscall.c:5777
__do_sys_bpf kernel/bpf/syscall.c:5902 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5900 [inline]
__x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5900
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&htab->lockdep_key#449);
lock(&htab->lockdep_key#448);
lock(&htab->lockdep_key#449);
lock(&htab->lockdep_key#448);
*** DEADLOCK ***
4 locks held by syz.0.465/7042:
#0: ffffffff8e320f68 (pcpu_alloc_mutex){+.+.}-{4:4}, at: pcpu_alloc_noprof+0xc5a/0x1680 mm/percpu.c:1782
#1: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#1: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#1: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline]
#1: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2412
#2: ffff88804a89d338 (&htab->lockdep_key#449){....}-{2:2}, at: htab_lock_bucket kernel/bpf/hashtab.c:167 [inline]
#2: ffff88804a89d338 (&htab->lockdep_key#449){....}-{2:2}, at: htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1483
#3: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline]
#3: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline]
#3: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: __bpf_trace_run kernel/trace/bpf_trace.c:2370 [inline]
#3: ffffffff8e1bcc80 (rcu_read_lock){....}-{1:3}, at: bpf_trace_run2+0x1c2/0x590 kernel/trace/bpf_trace.c:2412
stack backtrace:
CPU: 2 UID: 0 PID: 7042 Comm: syz.0.465 Not tainted 6.14.0-rc4-syzkaller-00073-g5394eea10651 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_circular_bug+0x490/0x760 kernel/locking/lockdep.c:2076
check_noncircular+0x31a/0x400 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 kernel/locking/lockdep.c:3906 [inline]
__lock_acquire+0x249e/0x3c40 kernel/locking/lockdep.c:5228
lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5851
__raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline]
_raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154
htab_lock_bucket kernel/bpf/hashtab.c:167 [inline]
htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1483
bpf_prog_6f5f05285f674219+0x43/0x4c
bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
__bpf_prog_run include/linux/filter.h:701 [inline]
bpf_prog_run include/linux/filter.h:708 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline]
bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2412
__bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95
__traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95
__preempt_count_dec_and_test arch/x86/include/asm/preempt.h:94 [inline]
class_preempt_notrace_destructor include/linux/preempt.h:481 [inline]
__do_trace_contention_begin include/trace/events/lock.h:95 [inline]
trace_contention_begin.constprop.0+0xf3/0x170 include/trace/events/lock.h:95
__pv_queued_spin_lock_slowpath+0x10b/0xc90 kernel/locking/qspinlock.c:402
pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:577 [inline]
queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline]
queued_spin_lock include/asm-generic/qspinlock.h:114 [inline]
do_raw_spin_lock+0x210/0x2c0 kernel/locking/spinlock_debug.c:116
htab_lock_bucket kernel/bpf/hashtab.c:167 [inline]
htab_lru_map_delete_elem+0x1c8/0x790 kernel/bpf/hashtab.c:1483
bpf_prog_6f5f05285f674219+0x43/0x4c
bpf_dispatcher_nop_func include/linux/bpf.h:1290 [inline]
__bpf_prog_run include/linux/filter.h:701 [inline]
bpf_prog_run include/linux/filter.h:708 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2371 [inline]
bpf_trace_run2+0x231/0x590 kernel/trace/bpf_trace.c:2412
__bpf_trace_contention_begin+0xca/0x110 include/trace/events/lock.h:95
__traceiter_contention_begin+0x5a/0xa0 include/trace/events/lock.h:95
__do_trace_contention_begin include/trace/events/lock.h:95 [inline]
trace_contention_begin+0xd2/0x140 include/trace/events/lock.h:95
__mutex_lock_common kernel/locking/mutex.c:587 [inline]
__mutex_lock+0x1a8/0xb10 kernel/locking/mutex.c:730
pcpu_alloc_noprof+0xc5a/0x1680 mm/percpu.c:1782
bpf_map_alloc_percpu+0x9a/0x4b0 kernel/bpf/syscall.c:555
prealloc_init kernel/bpf/hashtab.c:341 [inline]
htab_map_alloc+0x1231/0x17b0 kernel/bpf/hashtab.c:579
map_create+0x5c5/0x1d20 kernel/bpf/syscall.c:1455
__sys_bpf+0x4391/0x49c0 kernel/bpf/syscall.c:5777
__do_sys_bpf kernel/bpf/syscall.c:5902 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5900 [inline]
__x64_sys_bpf+0x78/0xc0 kernel/bpf/syscall.c:5900
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f512cf8d169
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:00007f512de6e038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f512d1a5fa0 RCX: 00007f512cf8d169
RDX: 0000000000000048 RSI: 00004000000009c0 RDI: 0000000000000000
RBP: 00007f512d00e2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000001 R14: 00007f512d1a5fa0 R15: 00007ffd54adadd8
</TASK>