syzbot


BUG: soft lockup in bitmap_port_gc

Status: moderation: reported on 2026/02/26 04:28
Subsystems: lsm
[Documentation on labels]
Reported-by: syzbot+ba02dcb9f53d069cb0d9@syzkaller.appspotmail.com
First crash: 8d16h, last: 8d16h
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in bitmap_port_gc netfilter 1 1 629d 629d 0/29 auto-obsoleted due to no activity on 2024/08/10 09:32

Sample crash report:
watchdog: BUG: soft lockup - CPU#1 stuck for 143s! [syz.7.1057:12057]
Modules linked in:
irq event stamp: 14494615
hardirqs last  enabled at (14494614): [<ffffffff8bad1f2e>] irqentry_exit+0x59e/0x620 kernel/entry/common.c:242
hardirqs last disabled at (14494615): [<ffffffff8bad093e>] sysvec_apic_timer_interrupt+0xe/0xc0 arch/x86/kernel/apic/apic.c:1056
softirqs last  enabled at (5378430): [<ffffffff8187fdef>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last  enabled at (5378430): [<ffffffff8187fdef>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last  enabled at (5378430): [<ffffffff8187fdef>] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
softirqs last disabled at (5378433): [<ffffffff8187fdef>] __do_softirq kernel/softirq.c:656 [inline]
softirqs last disabled at (5378433): [<ffffffff8187fdef>] invoke_softirq kernel/softirq.c:496 [inline]
softirqs last disabled at (5378433): [<ffffffff8187fdef>] __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
CPU: 1 UID: 0 PID: 12057 Comm: syz.7.1057 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x27/0x70 kernel/kcov.c:217
Code: 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0d 68 13 56 11 65 8b 15 89 13 56 11 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 <83> b9 54 16 00 00 00 74 2c 8b 91 30 16 00 00 83 fa 02 75 21 48 8b
RSP: 0018:ffffc90000a08bc8 EFLAGS: 00000246
RAX: ffffffff89ecb31c RBX: 0000000000002d00 RCX: ffff888057cc5ac0
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000002
RBP: ffff88802adfdaa0 R08: ffff888029ab45a7 R09: 1ffff110053568b4
R10: dffffc0000000000 R11: ffffed10053568b5 R12: 0000000000002d3c
R13: ffff88802adfdac0 R14: dffffc0000000000 R15: ffff88809300000c
FS:  00007fe4dff216c0(0000) GS:ffff888125566000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000002000 CR3: 000000007aab2000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 bitmap_port_gc+0x3cc/0x560 net/netfilter/ipset/ip_set_bitmap_gen.h:276
 call_timer_fn+0x192/0x640 kernel/time/timer.c:1748
 expire_timers kernel/time/timer.c:1799 [inline]
 __run_timers kernel/time/timer.c:2373 [inline]
 __run_timer_base+0x652/0x8b0 kernel/time/timer.c:2385
 run_timer_base kernel/time/timer.c:2394 [inline]
 run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2404
 handle_softirqs+0x22a/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0x5f/0x150 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:bpf_prog_array_valid include/linux/trace_events.h:453 [inline]
RIP: 0010:do_perf_trace_lock_acquire include/trace/events/lock.h:24 [inline]
RIP: 0010:perf_trace_lock_acquire+0x15a/0x440 include/trace/events/lock.h:24
Code: 8e 00 48 8b 44 24 08 48 03 03 48 89 44 24 08 49 8d 5c 24 68 48 89 d8 48 c1 e8 03 42 80 3c 30 00 74 08 48 89 df e8 86 ed 8e 00 <48> 83 3b 00 75 25 48 8b 5c 24 08 48 89 d8 48 c1 e8 03 42 80 3c 30
RSP: 0018:ffffc90004ae76c0 EFLAGS: 00000246
RAX: 1ffffffff1cc5855 RBX: ffffffff8e62c2a8 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8c27a460 RDI: ffffffff8c27a420
RBP: ffffc90004ae77c0 R08: 0000000000000002 R09: 0000000000000000
R10: ffffc90004ae7978 R11: ffffffff81b0b130 R12: ffffffff8e62c240
R13: 000000000000000d R14: dffffc0000000000 R15: 1ffff9200095cee0
 __do_trace_lock_acquire include/trace/events/lock.h:24 [inline]
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x2a4/0x2e0 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
 rcu_read_lock include/linux/rcupdate.h:850 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
 unwind_next_frame+0xc2/0x23c0 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4501 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4837
 lsm_inode_alloc security/security.c:228 [inline]
 security_inode_alloc+0x39/0x310 security/security.c:1189
 inode_init_always_gfp+0x9ed/0xdc0 fs/inode.c:307
 inode_init_always include/linux/fs.h:2922 [inline]
 alloc_inode+0x82/0x1b0 fs/inode.c:354
 new_inode_pseudo include/linux/fs.h:3003 [inline]
 sock_alloc net/socket.c:637 [inline]
 __sock_create+0x12d/0x9d0 net/socket.c:1569
 sock_create net/socket.c:1663 [inline]
 __sys_socket_create net/socket.c:1700 [inline]
 __sys_socket+0xd6/0x1b0 net/socket.c:1747
 __do_sys_socket net/socket.c:1761 [inline]
 __se_sys_socket net/socket.c:1759 [inline]
 __x64_sys_socket+0x7a/0x90 net/socket.c:1759
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe4def9c629
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe4dff21028 EFLAGS: 00000246 ORIG_RAX: 0000000000000029
RAX: ffffffffffffffda RBX: 00007fe4df215fa0 RCX: 00007fe4def9c629
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 000000000000001e
RBP: 00007fe4df032b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe4df216038 R14: 00007fe4df215fa0 R15: 00007ffd992b4ec8
 </TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:-1 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:172 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:191 [inline]
RIP: 0010:kasan_check_range+0x243/0x2c0 mm/kasan/generic.c:200
Code: 89 fb 48 c1 eb 28 84 db 0f 85 82 00 00 00 49 c1 ef 30 bb 07 00 00 00 45 84 ff 75 7d 4d 01 f3 49 01 db 4d 89 dc 4d 85 db 74 84 <4d> 01 d1 4d 39 cc 75 11 41 83 e0 07 45 0f be 09 45 39 c8 0f 8c 6b
RSP: 0018:ffffc90000a67588 EFLAGS: 00000286
RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff81a50152
RDX: 0000000000000001 RSI: 000000000000000c RDI: ffffc90000a67620
RBP: 0000000000000000 R08: ffffc90000a6762b R09: 1ffff9200014cec5
R10: dffffc0000000000 R11: fffff5200014cec5 R12: fffff5200014cec5
R13: ffffc90000a67620 R14: fffff5200014cec6 R15: 1ffff9200014cec4
FS:  0000000000000000(0000) GS:ffff888125466000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000054c0 CR3: 00000000332fc000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <TASK>
 __asan_memset+0x22/0x50 mm/kasan/shadow.c:84
 print_caller kernel/printk/printk.c:1366 [inline]
 info_print_prefix+0x1c2/0x360 kernel/printk/printk.c:1387
 record_print_text+0x176/0x450 kernel/printk/printk.c:1434
 printk_get_next_message+0x29c/0x880 kernel/printk/printk.c:3072
 console_emit_next_record kernel/printk/printk.c:3137 [inline]
 console_flush_one_record kernel/printk/printk.c:3269 [inline]
 console_flush_all+0x501/0xb20 kernel/printk/printk.c:3343
 __console_flush_and_unlock kernel/printk/printk.c:3373 [inline]
 console_unlock+0xd1/0x1c0 kernel/printk/printk.c:3413
 vprintk_emit+0x485/0x560 kernel/printk/printk.c:2479
 _printk+0xdd/0x130 kernel/printk/printk.c:2504
 check_hung_task kernel/hung_task.c:255 [inline]
 check_hung_uninterruptible_tasks kernel/hung_task.c:331 [inline]
 watchdog+0xb45/0x1030 kernel/hung_task.c:515
 kthread+0x388/0x470 kernel/kthread.c:467
 ret_from_fork+0x51e/0xb90 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/02/22 04:18 bpf-next 9cd168a2720b 6e7b5511 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-bpf-next-kasan-gce BUG: soft lockup in bitmap_port_gc
* Struck through repros no longer work on HEAD.