From: syzbot ci <syzbot+ci07724106297bc2b8@syzkaller.appspotmail.com>
To: brauner@kernel.org, coreteam@netfilter.org, davem@davemloft.net,
edumazet@kernel.org, fw@strlen.de, horms@kernel.org,
kuba@kernel.org, netdev@vger.kernel.org,
netfilter-devel@vger.kernel.org, pabeni@redhat.com,
pablo@netfilter.org, phil@nwl.cc, stable@vger.kernel.org,
tristan@talencesecurity.com, tristmd@gmail.com
Cc: syzbot@lists.linux.dev, syzkaller-bugs@googlegroups.com
Subject: [syzbot ci] Re: netfilter: pin file with get_file_rcu() before reading f_cred
Date: Wed, 14 Oct 2026 02:09:36 -0700 [thread overview]
Message-ID: <6acf46d0.a150a118.27e199.0061.GAE@google.com> (raw)
In-Reply-To: <20261013234329.2797868-1-tristmd@gmail.com>
syzbot ci has tested the following series
[v1] netfilter: pin file with get_file_rcu() before reading f_cred
https://lore.kernel.org/all/20261013234329.2797868-1-tristmd@gmail.com
* [PATCH nf 1/5] netfilter: xt_owner: pin file with get_file_rcu() before reading f_cred
* [PATCH nf 2/5] netfilter: nft_meta: pin file with get_file_rcu() before reading f_cred
* [PATCH nf 3/5] netfilter: nfnetlink_log: pin file with get_file_rcu() before reading f_cred
* [PATCH nf 4/5] netfilter: nfnetlink_queue: pin file with get_file_rcu() before reading f_cred
* [PATCH nf 5/5] netfilter: nf_log_syslog: pin file with get_file_rcu() before reading f_cred
and found the following issues:
* BUG: soft lockup in inet_release
* BUG: soft lockup in tcp_write_timer
* INFO: rcu detected stall in __sock_release
* INFO: rcu detected stall in do_idle
* INFO: rcu detected stall in inet_release
Full report is available here:
https://ci.syzbot.org/series/12bffa5e-1b93-48be-972a-d42a2d609c08
***
BUG: soft lockup in inet_release
tree: nf
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf.git
base: ab699d296e066eb64f51d2a8a1d42237a3b186c8
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/2622922d-df96-41f8-b0fb-efd53f4efbef/config
watchdog: BUG: soft lockup - CPU#0 stuck for 143s! [syz.1.665:7928]
Modules linked in:
irq event stamp: 53103
hardirqs last enabled at (53102): [<ffffffff8be80f08>] irqentry_exit+0x218/0x910
hardirqs last disabled at (53103): [<ffffffff8be7fc2e>] sysvec_apic_timer_interrupt+0xe/0xc0
softirqs last enabled at (2568): [<ffffffff8a73a559>] ipt_do_table+0x2b9/0x15d0
softirqs last disabled at (2574): [<ffffffff8a01a607>] nfulnl_log_packet+0x267/0x2a50
CPU: 0 UID: 0 PID: 7928 Comm: syz.1.665 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:__sanitizer_cov_trace_pc+0x75/0x80
Code: 18 17 00 00 83 fa 02 75 21 48 8b 91 20 17 00 00 48 8b 32 48 8d 7e 01 8b 89 1c 17 00 00 48 39 cf 73 08 48 89 3a 48 89 44 f2 08 <e9> 96 1b 23 0a cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90004a2eec0 EFLAGS: 00000293
RAX: ffffffff8255c089 RBX: ffff8880254a0050 RCX: ffff88810c5c5a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002
RBP: ffffc90004a2f100 R08: ffff8881b97d955f R09: 1ffff110372fb2ab
R10: dffffc0000000000 R11: ffffed10372fb2ac R12: dffffc0000000000
R13: 1ffff11004a9400a R14: ffff8881b97d9400 R15: fffffffffffffff5
FS: 000055559266b500(0000) GS:ffff88818c4c3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000d8e000 CR3: 0000000115740000 CR4: 00000000000006f0
Call Trace:
<TASK>
get_file_rcu+0xd9/0x100
nfulnl_log_packet+0x1b02/0x2a50
nf_log_packet+0x49a/0x650
nft_log_eval+0x2c4/0x3b0
nft_do_chain+0x48d/0x1b10
nft_do_chain_ipv4+0x195/0x290
nf_hook_slow+0xc5/0x220
nf_hook+0x22a/0x3a0
__ip_local_out+0x558/0x6a0
ip_local_out+0x2a/0x190
__ip_queue_xmit+0x10df/0x1b10
__tcp_transmit_skb+0x2d18/0x47c0
tcp_send_active_reset+0x2a8/0x5a0
__tcp_close+0x43d/0xe70
tcp_close+0x28/0x110
inet_release+0x143/0x190
__sock_release+0xa0/0x1f0
sock_close+0x1c/0x30
__fput+0x418/0xa50
task_work_run+0x1d9/0x270
exit_to_user_mode_loop+0x204/0x770
do_syscall_64+0x328/0x520
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9944b9e1d9
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:00007ffdbcd33af8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f9944e27da0 RCX: 00007f9944b9e1d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f9944e27da0 R08: 00007f9944e26038 R09: 0000000000000000
R10: 00000000003ffc6c R11: 0000000000000246 R12: 00000000000187bd
R13: 00007f9944e2609c R14: 00000000000184ed R15: 00007ffdbcd33c00
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: bond1 bond_alb_monitor
RIP: 0010:kasan_check_range+0x7/0x2c0
Code: 48 c7 c6 bc 1f 6f 8e e8 47 7c ef fe 90 0f 0b cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 41 57 <41> 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 ae 01 00 00 4c 8d 04 37
RSP: 0018:ffffc90000116548 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffff8881b9073810 RCX: ffffffff8beacbc2
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8881b9073810
RBP: ffffc90000116650 R08: ffff8881b9073813 R09: 1ffff1103720e702
R10: dffffc0000000000 R11: ffffed103720e703 R12: 1ffff92000022cb4
R13: 0000000000000001 R14: ffffc900001165c0 R15: 1ffff1103720e702
FS: 0000000000000000(0000) GS:ffff8882a7cc3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200001000000 CR3: 00000001af03e000 CR4: 00000000000006f0
Call Trace:
<TASK>
native_queued_spin_lock_slowpath+0xc2/0x960
do_raw_spin_lock+0x26c/0x2f0
nfulnl_log_packet+0x267/0x2a50
nf_log_packet+0x49a/0x650
nft_log_eval+0x2c4/0x3b0
nft_do_chain+0x48d/0x1b10
nft_do_chain_ipv4+0x195/0x290
nf_hook_slow+0xc5/0x220
nf_hook+0x22a/0x3a0
__ip_local_out+0x558/0x6a0
ip_local_out+0x2a/0x190
iptunnel_xmit+0x626/0xd10
udp_tunnel_xmit_skb+0x29b/0x3e0
geneve_xmit+0x24f4/0x3350
dev_hard_start_xmit+0x2cd/0x830
__dev_queue_xmit+0x14d1/0x3920
alb_send_lp_vid+0x348/0x550
alb_send_learning_packets+0x12c/0x300
bond_alb_monitor+0x3d0/0x1820
process_scheduled_works+0xc3d/0x1630
worker_thread+0xa47/0xfb0
kthread+0x38b/0x480
ret_from_fork+0x514/0xb70
ret_from_fork_asm+0x1a/0x30
</TASK>
***
BUG: soft lockup in tcp_write_timer
tree: nf
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf.git
base: ab699d296e066eb64f51d2a8a1d42237a3b186c8
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/2622922d-df96-41f8-b0fb-efd53f4efbef/config
watchdog: BUG: soft lockup - CPU#0 stuck for 123s! [swapper/0:0]
Modules linked in:
irq event stamp: 1709023
hardirqs last enabled at (1709022): [<ffffffff810014ca>] asm_sysvec_apic_timer_interrupt+0x1a/0x20
hardirqs last disabled at (1709023): [<ffffffff8be7fc2e>] sysvec_apic_timer_interrupt+0xe/0xc0
softirqs last enabled at (1685548): [<ffffffff8188fd3b>] __irq_exit_rcu+0xcb/0x220
softirqs last disabled at (1685579): [<ffffffff8188fd3b>] __irq_exit_rcu+0xcb/0x220
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:get_file_rcu+0xbe/0x100
Code: 72 ff 4c 89 f7 e8 22 b1 f6 ff 49 c7 c7 f5 ff ff ff 49 81 ff 00 f0 ff ff 77 10 eb 35 e8 ab 2d 72 ff 49 81 ff 00 f0 ff ff 76 27 <e8> 9d 2d 72 ff 43 80 7c 25 00 00 0f 85 60 ff ff ff e9 63 ff ff ff
RSP: 0018:ffffc90000006fd0 EFLAGS: 00000206
RAX: ffffffff8255c089 RBX: ffff88811b418c50 RCX: ffffffff8fa8f000
RDX: 0000000000000100 RSI: 0000000000000100 RDI: 0000000000000002
RBP: 0000000000000000 R08: 0000000000000100 R09: 1ffff11022ee972b
R10: dffffc0000000000 R11: ffffed1022ee972c R12: dffffc0000000000
R13: 1ffff1102368318a R14: ffff88811774b800 R15: fffffffffffffff5
FS: 0000000000000000(0000) GS:ffff88818c4c3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f679c7eb8c0 CR3: 000000000fb48000 CR4: 00000000000006f0
Call Trace:
<IRQ>
owner_mt+0x28a/0x970
nft_match_eval+0x1ad/0x2b0
nft_do_chain+0x48d/0x1b10
nft_do_chain_ipv4+0x195/0x290
nf_hook_slow+0xc5/0x220
nf_hook+0x22a/0x3a0
__ip_local_out+0x558/0x6a0
ip_local_out+0x2a/0x190
__ip_queue_xmit+0x10df/0x1b10
__tcp_transmit_skb+0x2d18/0x47c0
__tcp_retransmit_skb+0xb15/0x16a0
tcp_retransmit_skb+0x33/0x440
tcp_retransmit_timer+0x1d5f/0x3830
tcp_write_timer+0x15c/0x2d0
call_timer_fn+0x18d/0x5f0
__run_timer_base+0x652/0x8b0
run_timer_softirq+0xb7/0x170
handle_softirqs+0x226/0x860
__irq_exit_rcu+0xcb/0x220
irq_exit_rcu+0x9/0x30
sysvec_apic_timer_interrupt+0xa6/0xc0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:pv_native_safe_halt+0xf/0x20
Code: ab 8b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d d3 85 21 00 fb f4 <e9> 8c 08 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffffff8fa07ca0 EFLAGS: 00000202
RAX: 000000000019b849 RBX: ffffffff819bcc20 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e46796e RDI: ffffffff8c6dd780
RBP: ffffffff8fa07d78 R08: ffff888120e33a1b R09: 1ffff110241c6743
R10: dffffc0000000000 R11: ffffed10241c6744 R12: 0000000000000000
R13: 1ffffffff1f51e00 R14: 1ffffffff1f40f9c R15: dffffc0000000000
default_idle+0x9/0x20
default_idle_call+0x72/0xb0
do_idle+0x2e0/0x540
cpu_startup_entry+0x43/0x60
rest_init+0x378/0x3a0
start_kernel+0x392/0x3e0
x86_64_start_reservations+0x24/0x30
x86_64_start_kernel+0x137/0x1b0
common_startup_64+0x13e/0x157
</TASK>
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 24 Comm: ksoftirqd/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:native_apic_msr_write+0x39/0x50
Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 cc cc cc cc cc 89 f6 31 d2 e9 a6 07 a8 03 66 0f 1f 44 00
RSP: 0018:ffffc900001e7ab0 EFLAGS: 00000046
RAX: 000000000003088e RBX: ffff88823c623c80 RCX: 0000000000000838
RDX: 0000000000000000 RSI: 000000000003088e RDI: 0000000000000838
RBP: ffffc900001e7b70 R08: 0000000000000100 R09: 0000000000000001
R10: 0000000000000003 R11: ffffffff81754510 R12: 000000000003088e
R13: dffffc0000000000 R14: 0000000010007570 R15: 0000000000000020
FS: 0000000000000000(0000) GS:ffff8882a7cc3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f272104ea09 CR3: 00000001be49e000 CR4: 00000000000006f0
Call Trace:
<TASK>
lapic_next_event+0x11/0x20
clockevents_program_event+0x385/0x630
__hrtimer_rearm_deferred+0x36c/0x4b0
irqentry_exit+0x8d3/0x910
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80
Code: f7 e8 cd 2f b9 f5 f7 c3 00 02 00 00 74 05 e8 50 7d e5 f5 9c 58 a9 00 02 00 00 75 29 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 04 2d aa f5 65 48 8b 05 4c 10 ab 08 48 85 c0 74 18 5b 41 5e e9
RSP: 0018:ffffc900001e7cc8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000283 RCX: 8000000000000101
RDX: 0000000000000000 RSI: ffffffff8e46796e RDI: 0000000000000001
RBP: 0000000000000003 R08: ffffffff917a6d7f R09: 1ffffffff22f4daf
R10: dffffc0000000000 R11: fffffbfff22f4db0 R12: 0000000000000009
R13: 0000000000000008 R14: ffff88823c628280 R15: 0000000000000100
handle_softirqs+0x226/0x860
run_ksoftirqd+0x36/0x60
smpboot_thread_fn+0x565/0xa70
kthread+0x38b/0x480
ret_from_fork+0x514/0xb70
ret_from_fork_asm+0x1a/0x30
</TASK>
***
INFO: rcu detected stall in __sock_release
tree: nf
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf.git
base: ab699d296e066eb64f51d2a8a1d42237a3b186c8
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/2622922d-df96-41f8-b0fb-efd53f4efbef/config
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=21357, q=124 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294959758-4294949256), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10502 jiffies! g21357 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:R running task stack:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
<TASK>
__schedule+0x17db/0x58f0
schedule+0x164/0x2b0
schedule_timeout+0x152/0x2c0
rcu_gp_fqs_loop+0x30c/0x11f0
rcu_gp_kthread+0x9e/0x2b0
kthread+0x38b/0x480
ret_from_fork+0x514/0xb70
ret_from_fork_asm+0x1a/0x30
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 8420 Comm: syz.2.714 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:its_return_thunk+0x0/0x10
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 e9 3b 05 48 f5 cc
RSP: 0018:ffffc90000a17ce0 EFLAGS: 00000246
RAX: ffffffff8255c073 RBX: ffff8881bab1c250 RCX: ffff88810e591e00
RDX: 0000000000000300 RSI: 0000000000000100 RDI: 0000000000000002
RBP: ffffc90000a17f00 R08: 0000000000000100 R09: 1ffff1102da8a8ab
R10: dffffc0000000000 R11: ffffed102da8a8ac R12: dffffc0000000000
R13: 1ffff1103756384a R14: ffff88816d454400 R15: fffffffffffffff5
FS: 0000555583040500(0000) GS:ffff8882a7cc3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c35ea7b CR3: 00000001bd488000 CR4: 00000000000006f0
Call Trace:
<IRQ>
get_file_rcu+0xc3/0x100
nfulnl_log_packet+0x1b02/0x2a50
nf_log_packet+0x49a/0x650
nft_log_eval+0x2c4/0x3b0
nft_do_chain+0x48d/0x1b10
nft_do_chain_ipv4+0x195/0x290
nf_hook_slow+0xc5/0x220
nf_hook+0x22a/0x3a0
__ip_local_out+0x558/0x6a0
ip_local_out+0x2a/0x190
__ip_queue_xmit+0x10df/0x1b10
__tcp_transmit_skb+0x2d18/0x47c0
tcp_write_xmit+0x1bfa/0x6400
tcp_send_loss_probe+0x20b/0x920
tcp_write_timer+0x15c/0x2d0
call_timer_fn+0x18d/0x5f0
__run_timer_base+0x652/0x8b0
run_timer_softirq+0xb7/0x170
handle_softirqs+0x226/0x860
__irq_exit_rcu+0xcb/0x220
irq_exit_rcu+0x9/0x30
sysvec_apic_timer_interrupt+0xa6/0xc0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:lock_acquire+0x232/0x350
Code: ff ff ff e8 b0 bd 44 0a f7 44 24 10 00 02 00 00 0f 84 38 ff ff ff 65 48 8b 05 42 88 f2 12 48 3b 44 24 50 75 33 fb 48 83 c4 58 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 87 5f da
RSP: 0018:ffffc900063cfc40 EFLAGS: 00000292
RAX: be519d89c48d4400 RBX: 0000000000000001 RCX: 0000000000000046
RDX: 000000000185c73d RSI: ffffffff8e6f0840 RDI: ffffffff8c6dd780
RBP: ffff88810e591e00 R08: ffffffff89a7dfaa R09: 0000000000000000
R10: dffffc0000000000 R11: ffffffff89a90a00 R12: ffff8880134a6240
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000246
down_write+0x96/0x200
__sock_release+0x7a/0x1f0
sock_close+0x1c/0x30
__fput+0x418/0xa50
task_work_run+0x1d9/0x270
exit_to_user_mode_loop+0x204/0x770
do_syscall_64+0x328/0x520
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ced79e1d9
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:00007fffd96153a8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fffd9615490 RCX: 00007f2ced79e1d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 000000000001da87 R08: 0000000000000001 R09: 0000000000000000
R10: 0000001b31520000 R11: 0000000000000246 R12: 00007fffd96154d0
R13: 00007f2ceda25fac R14: 000000000001dad7 R15: 00007f2ceda25fa0
</TASK>
***
INFO: rcu detected stall in do_idle
tree: nf
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf.git
base: ab699d296e066eb64f51d2a8a1d42237a3b186c8
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/2622922d-df96-41f8-b0fb-efd53f4efbef/config
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=96fc/1/0x4000000000000000 softirq=149048/149048 fqs=48
rcu: (t=10500 jiffies g=207709 q=131 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10402 jiffies! g207709 f0x0 RCU_GP_WAIT_FQS(5) ->state=I
rcu: Possible timer handling issue on cpu=1 timer-softirq=87930
rcu: rcu_preempt kthread starved for 10403 jiffies! g207709 f0x0 RCU_GP_WAIT_FQS(5) ->state=I ->cpu=1
rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt state:I stack:28104 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
<TASK>
__schedule+0x17db/0x58f0
schedule+0x164/0x2b0
schedule_timeout+0x152/0x2c0
rcu_gp_fqs_loop+0x30c/0x11f0
rcu_gp_kthread+0x9e/0x2b0
kthread+0x38b/0x480
ret_from_fork+0x514/0xb70
ret_from_fork_asm+0x1a/0x30
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:kasan_check_range+0x1d/0x2c0
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 55 41 57 41 56 41 55 41 54 53 b0 01 48 85 f6 0f 84 ae 01 00 00 4c 8d 04 37 <49> 39 f8 0f 82 36 02 00 00 49 b9 00 00 00 00 00 80 ff ff eb 0d cc
RSP: 0018:ffffc90000a18a48 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffff888115985810 RCX: ffffffff8beacbc2
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888115985810
RBP: ffffc90000a18b70 R08: ffff888115985814 R09: 1ffff11022b30b02
R10: dffffc0000000000 R11: ffffed1022b30b03 R12: 1ffff92000143158
R13: 0000000000000001 R14: ffffc90000a18ae0 R15: 1ffff11022b30b02
FS: 0000000000000000(0000) GS:ffff8882a7cc3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4106beb8c0 CR3: 00000001a7d98000 CR4: 00000000000006f0
Call Trace:
<IRQ>
native_queued_spin_lock_slowpath+0xc2/0x960
do_raw_spin_lock+0x26c/0x2f0
nfulnl_timer+0x20/0x110
call_timer_fn+0x18d/0x5f0
__run_timer_base+0x652/0x8b0
run_timer_softirq+0xb7/0x170
handle_softirqs+0x226/0x860
__irq_exit_rcu+0xcb/0x220
irq_exit_rcu+0x9/0x30
sysvec_apic_timer_interrupt+0xa6/0xc0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:pv_native_safe_halt+0xf/0x20
Code: ab 8b 02 c3 cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa eb 07 0f 00 2d d3 85 21 00 fb f4 <e9> 8c 08 03 00 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90
RSP: 0018:ffffc900001a7e40 EFLAGS: 00000206
RAX: 00000000005c2139 RBX: ffffffff819bcc20 RCX: 8000000000000001
RDX: 0000000000000001 RSI: ffffffff8e46796e RDI: ffffffff8c6dd780
RBP: ffffc900001a7f10 R08: ffff88823c633a1b R09: 1ffff110478c6743
R10: dffffc0000000000 R11: ffffed10478c6744 R12: 0000000000000000
R13: 1ffff1102c09d000 R14: 1ffff92000034fd0 R15: dffffc0000000000
default_idle+0x9/0x20
default_idle_call+0x72/0xb0
do_idle+0x2e0/0x540
cpu_startup_entry+0x43/0x60
start_secondary+0x101/0x110
common_startup_64+0x13e/0x157
</TASK>
CPU: 0 UID: 0 PID: 31900 Comm: syz.3.6377 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:get_file_rcu+0x5f/0x100
Code: e2 ff 4c 8b 33 4d 85 f6 0f 84 98 00 00 00 49 8d be 58 01 00 00 be 08 00 00 00 e8 0c 02 e3 ff 31 f6 f0 49 83 86 58 01 00 00 01 <40> 0f 99 c5 40 0f 98 c6 bf 02 00 00 00 e8 6f 31 72 ff 40 84 ed 74
RSP: 0018:ffffc9000694eec8 EFLAGS: 00000286
RAX: ffffffff8255c001 RBX: ffff8881aa509250 RCX: ffffffff8255c004
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88811134b958
RBP: ffffc9000694f100 R08: ffff88811134b95f R09: 1ffff1102226972b
R10: dffffc0000000000 R11: ffffed102226972c R12: dffffc0000000000
R13: 1ffff110354a124a R14: ffff88811134b800 R15: fffffffffffffff5
FS: 000055556a26b500(0000) GS:ffff88818c4c3000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f41079d6ff8 CR3: 00000001a589a000 CR4: 00000000000006f0
Call Trace:
<TASK>
nfulnl_log_packet+0x1b02/0x2a50
nf_log_packet+0x49a/0x650
nft_log_eval+0x2c4/0x3b0
nft_do_chain+0x48d/0x1b10
nft_do_chain_ipv4+0x195/0x290
nf_hook_slow+0xc5/0x220
nf_hook+0x22a/0x3a0
__ip_local_out+0x558/0x6a0
ip_local_out+0x2a/0x190
__ip_queue_xmit+0x10df/0x1b10
__tcp_transmit_skb+0x2d18/0x47c0
tcp_send_active_reset+0x2a8/0x5a0
__tcp_close+0x43d/0xe70
tcp_close+0x28/0x110
inet_release+0x143/0x190
__sock_release+0xa0/0x1f0
sock_close+0x1c/0x30
__fput+0x418/0xa50
task_work_run+0x1d9/0x270
exit_to_user_mode_loop+0x204/0x770
do_syscall_64+0x328/0x520
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f584b99e1d9
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:00007ffdb6062668 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f584bc27da0 RCX: 00007f584b99e1d9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f584bc27da0 R08: 00007f584bc26218 R09: 0000000000000000
R10: 000000000003fd20 R11: 0000000000000246 R12: 000000000013db89
R13: 00007f584bc2636c R14: 000000000013d8a7 R15: 00007ffdb6062770
</TASK>
***
INFO: rcu detected stall in inet_release
tree: nf
URL: https://kernel.googlesource.com/pub/scm/linux/kernel/git/netfilter/nf.git
base: ab699d296e066eb64f51d2a8a1d42237a3b186c8
arch: amd64
compiler: Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config: https://ci.syzbot.org/builds/2622922d-df96-41f8-b0fb-efd53f4efbef/config
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7332
rcu: (detected by 0, t=10502 jiffies, g=20017, q=4308 ncpus=2)
task:syz.1.387 state:R running task stack:25040 pid:7332 tgid:7330 ppid:5598 task_flags:0x400140 flags:0x00080003
Call Trace:
<IRQ>
sched_show_task+0x4aa/0x5f0
print_other_cpu_stall+0xfc1/0x1350
rcu_sched_clock_irq+0x9fe/0x10e0
update_process_times+0x23b/0x2f0
tick_nohz_handler+0x38f/0x6b0
__hrtimer_run_queues+0x371/0xa10
hrtimer_interrupt+0x4cd/0xaa0
__sysvec_apic_timer_interrupt+0x102/0x430
sysvec_apic_timer_interrupt+0xa1/0xc0
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20
RIP: 0010:__sanitizer_cov_trace_const_cmp1+0x8/0xb0
Code: 0a 10 48 89 74 0a 18 48 89 44 0a 20 c3 cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 68 de cd 12 65 48 8b 15 68 de cd 12 f7 c2 00 01 00 ff
RSP: 0018:ffffc90007257228 EFLAGS: 00000286
RAX: ffffffff8255c021 RBX: ffff888023d91850 RCX: ffffffff8255c004
RDX: 0000000000000001 RSI: 0000000000000001 RDI: 0000000000000002
RBP: 0000000000000000 R08: ffff888025fab95f R09: 1ffff11004bf572b
R10: dffffc0000000000 R11: ffffed1004bf572c R12: dffffc0000000000
R13: 1ffff110047b230a R14: ffff888025fab800 R15: fffffffffffffff5
get_file_rcu+0x71/0x100
owner_mt+0x28a/0x970
nft_match_eval+0x1ad/0x2b0
nft_do_chain+0x48d/0x1b10
nft_do_chain_ipv4+0x195/0x290
nf_hook_slow+0xc5/0x220
nf_hook+0x22a/0x3a0
__ip_local_out+0x558/0x6a0
ip_local_out+0x2a/0x190
__ip_queue_xmit+0x10df/0x1b10
__tcp_transmit_skb+0x2d18/0x47c0
tcp_send_active_reset+0x2a8/0x5a0
mptcp_do_fastclose+0x2d8/0x4a0
__mptcp_close+0x21c/0xd10
mptcp_close+0x28/0x1a0
inet_release+0x143/0x190
__sock_release+0xa0/0x1f0
sock_close+0x1c/0x30
__fput+0x418/0xa50
fput_close_sync+0x11f/0x240
__x64_sys_close+0x7e/0x110
do_syscall_64+0x166/0x520
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2ae4d9e1d9
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:00007f2ae5c36028 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00007f2ae5026090 RCX: 00007f2ae4d9e1d9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f2ae4e35888 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2ae5026128 R14: 00007f2ae5026090 R15: 00007ffd59d7a8d8
</TASK>
***
If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
Tested-by: syzbot@syzkaller.appspotmail.com
---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.
To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.
Notes:
- The patch will be applied on top of the tested series (as an
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- To test a new version of the whole series, please send it directly
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prev parent reply other threads:[~2026-10-14 9:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-13 23:43 [PATCH nf 0/5] netfilter: pin file with get_file_rcu() before reading f_cred Tristan Madani
2026-10-13 23:43 ` [PATCH nf 1/5] netfilter: xt_owner: " Tristan Madani
2026-10-13 23:43 ` [PATCH nf 2/5] netfilter: nft_meta: " Tristan Madani
2026-10-13 23:43 ` [PATCH nf 3/5] netfilter: nfnetlink_log: " Tristan Madani
2026-10-13 23:43 ` [PATCH nf 4/5] netfilter: nfnetlink_queue: " Tristan Madani
2026-10-13 23:43 ` [PATCH nf 5/5] netfilter: nf_log_syslog: " Tristan Madani
2026-10-13 23:50 ` [PATCH nf 0/5] netfilter: " netdev-bot+sinfo
2026-10-14 9:09 ` syzbot ci [this message]
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