[v6.1] INFO: rcu detected stall in sys_recvmmsg (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 347385861c50 Linux 6.1.84
git tree: linux-6.1.y
console output: https://syzkaller.appspot.com/x/log.txt?x=168dca9d180000
kernel config: https://syzkaller.appspot.com/x/.config?x=40dfd13b04bfc094
dashboard link: https://syzkaller.appspot.com/bug?extid=21ec4549d7d2c6bf9a0b
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/73d2a8622b6e/disk-34738586.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/e7bc2e0101a7/vmlinux-34738586.xz
kernel image: https://storage.googleapis.com/syzbot-assets/7b96d1168608/bzImage-34738586.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+21ec45...@syzkaller.appspotmail.com

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P16553/1:b..l
(detected by 1, t=10502 jiffies, g=87517, q=6 ncpus=2)
task:syz-executor.1 state:R running task stack:25560 pid:16553 ppid:14760 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870
irqentry_exit+0x53/0x80 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653
RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666
Code: 2b 00 74 08 4c 89 f7 e8 1f a8 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc90005a97640 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff92000b52ed4 RCX: 1ffff92000b52e74
RDX: dffffc0000000000 RSI: ffffffff8aec0040 RDI: ffffffff8b3d2d20
RBP: ffffc90005a97790 R08: dffffc0000000000 R09: fffffbfff2093045
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000b52ed0
R13: dffffc0000000000 R14: ffffc90005a976a0 R15: 0000000000000246
rcu_lock_acquire include/linux/rcupdate.h:350 [inline]
rcu_read_lock include/linux/rcupdate.h:791 [inline]
af_alg_wmem_wakeup+0xd0/0x330 crypto/af_alg.c:734
skcipher_recvmsg+0xdeb/0xe50 crypto/algif_skcipher.c:177
____sys_recvmsg+0x285/0x530
___sys_recvmsg net/socket.c:2775 [inline]
do_recvmmsg+0x46d/0xad0 net/socket.c:2869
__sys_recvmmsg net/socket.c:2948 [inline]
__do_sys_recvmmsg net/socket.c:2971 [inline]
__se_sys_recvmmsg net/socket.c:2964 [inline]
__x64_sys_recvmmsg+0x195/0x240 net/socket.c:2964
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f4b3a47de69
RSP: 002b:00007f4b3b2af0c8 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f4b3a5abf80 RCX: 00007f4b3a47de69
RDX: 03ffffffffffff62 RSI: 00000000200005c0 RDI: 0000000000000006
RBP: 00007f4b3a4ca47a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f4b3a5abf80 R15: 00007ffd54c3e788
</TASK>
rcu: rcu_preempt kthread starved for 10534 jiffies! g87517 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:25528 pid:16 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x142d/0x4550 kernel/sched/core.c:6558
schedule+0xbf/0x180 kernel/sched/core.c:6634
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
rcu_gp_fqs_loop+0x2d2/0x1120 kernel/rcu/tree.c:1706
rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1905
kthread+0x28d/0x320 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:307
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.1.84-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:113 [inline]
RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572
Code: 39 f6 f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 24 f6 fc f6 0f 1f 44 00 00 e8 8a 35 f6 f6 0f 00 2d 93 f5 b2 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 7b ac 4d f7
RSP: 0000:ffffc90000177b80 EFLAGS: 000002d3
RAX: ffffffff8a945166 RBX: 0000000000000000 RCX: ffff88813fef9dc0
RDX: 0000000000000000 RSI: ffffffff8aebeec0 RDI: ffffffff8b3d2d20
RBP: ffffc90000177c10 R08: ffffffff8a945148 R09: ffffed1027fdf3b9
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200002ef70
R13: ffff888013bf7004 R14: ffffc90000177ba0 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020c57000 CR3: 0000000063a75000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
</IRQ>
<TASK>
acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:709
cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239
cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356
call_cpuidle kernel/sched/idle.c:155 [inline]
cpuidle_idle_call kernel/sched/idle.c:236 [inline]
do_idle+0x3ce/0x680 kernel/sched/idle.c:303
cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401
start_secondary+0xe4/0xf0 arch/x86/kernel/smpboot.c:281
secondary_startup_64_no_verify+0xcf/0xdb
</TASK>


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