syzbot


INFO: rcu detected stall in skcipher_recvmsg (2)

Status: auto-obsoleted due to no activity on 2026/04/12 14:32
Subsystems: crypto mm
[Documentation on labels]
First crash: 155d, last: 108d
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in skcipher_recvmsg crypto 1 2 479d 484d 0/29 auto-obsoleted due to no activity on 2025/04/06 18:57

Sample crash report:
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P29332/1:b..l P38/1:b..l
rcu: 	(detected by 1, t=10503 jiffies, g=289273, q=7055 ncpus=2)
task:khugepaged      state:R  running task     stack:26664 pid:38    tgid:38    ppid:2      task_flags:0x200040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7206
 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752
 trace_lock_acquire include/trace/events/lock.h:24 [inline]
 lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:867 [inline]
 start_flush_work kernel/workqueue.c:4179 [inline]
 __flush_work+0xf3/0xbc0 kernel/workqueue.c:4237
 __lru_add_drain_all+0x56a/0x5e0 mm/swap.c:885
 khugepaged_do_scan mm/khugepaged.c:2540 [inline]
 khugepaged+0x197/0x16a0 mm/khugepaged.c:2609
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:syz.3.7508      state:R  running task     stack:24904 pid:29332 tgid:29321 ppid:13589  task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256
 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319
Code: 06 77 3c f6 90 0f 0b 90 90 90 eb c4 cc cc cc cc cc cc cc 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 31 c0 83 3d a7 46 36 04 00 74 1e 83 3d aa 75 36 04 00
RSP: 0018:ffffc9000d8676e0 EFLAGS: 00000246
RAX: ffffffff845ef63d RBX: ffff888026231180 RCX: 0000000000080000
RDX: ffffc90010e68000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffffff845ef450 R08: ffff888026231067 R09: 1ffff11004c4620c
R10: dffffc0000000000 R11: ffffed1004c4620d R12: dffffc0000000000
R13: ffffffff845ef450 R14: 0000000000000000 R15: 1ffff11004c46230
 rcu_read_unlock include/linux/rcupdate.h:895 [inline]
 af_alg_wmem_wakeup+0x2a2/0x440 crypto/af_alg.c:852
 skcipher_recvmsg+0x115c/0x11d0 crypto/algif_skcipher.c:241
 sock_recvmsg_nosec+0x186/0x1c0 net/socket.c:1078
 ____sys_recvmsg+0x3aa/0x460 net/socket.c:2848
 ___sys_recvmsg+0x1b5/0x510 net/socket.c:2892
 do_recvmmsg+0x307/0x770 net/socket.c:2987
 __sys_recvmmsg net/socket.c:3061 [inline]
 __do_sys_recvmmsg net/socket.c:3084 [inline]
 __se_sys_recvmmsg net/socket.c:3077 [inline]
 __x64_sys_recvmmsg+0x190/0x240 net/socket.c:3077
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ffa8ef8f749
RSP: 002b:00007ffa8fe73038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007ffa8f1e6180 RCX: 00007ffa8ef8f749
RDX: 03ffffffffffff67 RSI: 0000200000002440 RDI: 0000000000000007
RBP: 00007ffa8f013f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffa8f1e6218 R14: 00007ffa8f1e6180 R15: 00007ffa8f30fa28
 </TASK>
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:32:cd:8c:b0:1a:cc, vlan:0)

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/11/27 09:06 upstream 4941a17751c9 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in skcipher_recvmsg
2026/01/12 14:25 net-next 60d8484c4cec d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-net-kasan-gce INFO: rcu detected stall in skcipher_recvmsg
* Struck through repros no longer work on HEAD.