Hello, syzbot found the following issue on:
HEAD commit: 516471569089 Merge tag 'libcrypto-fixes-for-linus' of git:.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10ead77c580000 kernel config: https://syzkaller.appspot.com/x/.config?x=a11e0f726bfb6765 dashboard link: https://syzkaller.appspot.com/bug?extid=62348313fb96b25955aa compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=147f4d58580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/5a94a2d04644/disk-51647156.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/31d4eeac4086/vmlinux-51647156.xz kernel image: https://storage.googleapis.com/syzbot-assets/e58508861b69/bzImage-51647156.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: [email protected] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5953/1:b..l P3819/1:b..l P36/1:b..l rcu: (detected by 0, t=10502 jiffies, g=8897, q=377 ncpus=2) task:kworker/u8:2 state:R running task stack:22840 pid:36 tgid:36 ppid:2 task_flags:0x24248060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: <TASK> context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:138 [inline] RIP: 0010:cpumask_check include/linux/cpumask.h:145 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:649 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1231 [inline] RIP: 0010:trace_lock_acquire include/trace/events/lock.h:24 [inline] RIP: 0010:lock_acquire+0x3b/0x330 kernel/locking/lockdep.c:5831 Code: 89 d5 41 54 45 89 c4 55 89 cd 53 48 89 fb 48 83 ec 38 65 48 8b 05 cd b4 18 12 48 89 44 24 30 31 c0 66 90 65 8b 05 e9 b4 18 12 <83> f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 72 b8 ee 0e 0f 82 74 RSP: 0018:ffffc90000ac66d0 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffffffff8e3c9620 RCX: 0000000000000002 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8e3c9620 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000008490 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xd1/0x20b0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270 mempool_alloc_noprof+0x1b4/0x2f0 mm/mempool.c:567 bio_alloc_bioset+0x3de/0x8c0 block/bio.c:565 bio_alloc_clone block/bio.c:873 [inline] bio_split+0x13b/0x440 block/bio.c:1711 bio_submit_split_bioset+0x31/0xa40 block/blk-merge.c:122 bio_submit_split+0xa8/0x160 block/blk-merge.c:152 __bio_split_to_limits block/blk.h:402 [inline] blk_mq_submit_bio+0x67b/0x2c50 block/blk-mq.c:3184 __submit_bio+0x3cc/0x690 block/blk-core.c:637 __submit_bio_noacct_mq block/blk-core.c:724 [inline] submit_bio_noacct_nocheck+0x53d/0xbe0 block/blk-core.c:755 submit_bio_noacct+0x5bd/0x1f40 block/blk-core.c:879 ext4_io_submit+0xa6/0x140 fs/ext4/page-io.c:404 ext4_do_writepages+0xe42/0x3c80 fs/ext4/inode.c:2952 ext4_writepages+0x37a/0x7d0 fs/ext4/inode.c:3026 do_writepages+0x27a/0x600 mm/page-writeback.c:2598 __writeback_single_inode+0x168/0x14a0 fs/fs-writeback.c:1737 writeback_sb_inodes+0x72e/0x1ce0 fs/fs-writeback.c:2030 __writeback_inodes_wb+0xf8/0x2d0 fs/fs-writeback.c:2107 wb_writeback+0x799/0xae0 fs/fs-writeback.c:2218 wb_check_old_data_flush fs/fs-writeback.c:2322 [inline] wb_do_writeback fs/fs-writeback.c:2375 [inline] wb_workfn+0x8a0/0xbb0 fs/fs-writeback.c:2403 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 </TASK> task:kworker/u8:14 state:R running task stack:25480 pid:3819 tgid:3819 ppid:2 task_flags:0x4208060 flags:0x00080000 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet Call Trace: <TASK> context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190 irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x79/0x330 kernel/locking/lockdep.c:5872 Code: 82 74 02 00 00 8b 35 0a e9 ee 0e 85 f6 0f 85 8d 00 00 00 48 8b 44 24 30 65 48 2b 05 89 b4 18 12 0f 85 ad 02 00 00 48 83 c4 38 <5b> 5d 41 5c 41 5d 41 5e 41 5f e9 08 38 e1 09 65 8b 05 95 b4 18 12 RSP: 0018:ffffc9000d107a00 EFLAGS: 00000296 RAX: 0000000000000000 RBX: ffffffff8e3c9620 RCX: 0000000042e2d81e RDX: 0000000000000000 RSI: ffffffff8daa7da3 RDI: ffffffff8bf2b380 RBP: 0000000000000002 R08: 000000007a5a0105 R09: 0000000057a5a010 R10: 0000000000000002 R11: ffff888033fc0b30 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] batadv_iv_ogm_slide_own_bcast_window net/batman-adv/bat_iv_ogm.c:761 [inline] batadv_iv_ogm_schedule_buff+0x5d0/0x14c0 net/batman-adv/bat_iv_ogm.c:833 batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:873 [inline] batadv_iv_ogm_schedule net/batman-adv/bat_iv_ogm.c:866 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x329/0x920 net/batman-adv/bat_iv_ogm.c:1709 process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 </TASK> task:udevd state:R running task stack:27112 pid:5953 tgid:5953 ppid:5190 task_flags:0x400140 flags:0x00080000 Call Trace: <TASK> context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 preempt_schedule_notrace+0x62/0xe0 kernel/sched/core.c:7140 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x8e/0xc0 kernel/rcu/tree.c:752 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x201/0x2d0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x3f9/0x20b0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:339 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270 lsm_file_alloc security/security.c:169 [inline] security_file_alloc+0x34/0x2b0 security/security.c:2380 init_file+0x93/0x4c0 fs/file_table.c:159 alloc_empty_file+0x73/0x1e0 fs/file_table.c:241 path_openat+0xde/0x3140 fs/namei.c:4773 do_filp_open+0x20b/0x470 fs/namei.c:4814 do_sys_openat2+0x121/0x290 fs/open.c:1430 do_sys_open fs/open.c:1436 [inline] __do_sys_openat fs/open.c:1452 [inline] __se_sys_openat fs/open.c:1447 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1447 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0d5b8a7407 RSP: 002b:00007ffee52231a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f0d5c0b1880 RCX: 00007f0d5b8a7407 RDX: 0000000000080000 RSI: 0000559b925f46d0 RDI: ffffffffffffff9c RBP: 0000559b925f46d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000009 </TASK> rcu: rcu_preempt kthread starved for 10623 jiffies! g8897 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:28328 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: <TASK> context_switch kernel/sched/core.c:5256 [inline] __schedule+0x1139/0x6150 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6960 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 </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: 6101 Comm: syz.1.30 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__lock_acquire+0x58/0x2890 kernel/locking/lockdep.c:5098 Code: 18 12 48 89 44 24 68 31 c0 85 db 0f 84 54 04 00 00 48 8b 07 49 89 fd 48 3d 00 86 b9 93 0f 84 42 04 00 00 44 8b 1d c8 b5 92 0c <45> 89 c7 89 f5 89 d3 45 89 c8 45 85 db 74 5d 48 3d 10 86 b9 93 74 RSP: 0018:ffffc90002fe78f8 EFLAGS: 00000006 RAX: ffffffff9ac2cf60 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888079e8d510 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000000 R10: ffffc90002fe7bd8 R11: 0000000000000001 R12: ffff88802db2c980 R13: ffff888079e8d510 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fa9d7eb66c0(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa9d7eb5f98 CR3: 000000005b10e000 CR4: 00000000003526f0 Call Trace: <TASK> lock_acquire kernel/locking/lockdep.c:5868 [inline] lock_acquire+0x179/0x330 kernel/locking/lockdep.c:5825 __mutex_lock_common kernel/locking/mutex.c:614 [inline] __mutex_lock+0x1aa/0x1ca0 kernel/locking/mutex.c:776 seccomp_do_user_notification.constprop.0+0xaa/0xe80 kernel/seccomp.c:1173 __seccomp_filter+0x8ea/0x11f0 kernel/seccomp.c:1338 __secure_computing+0x287/0x3b0 kernel/seccomp.c:1404 syscall_trace_enter+0x89/0x220 kernel/entry/syscall-common.c:44 syscall_enter_from_user_mode_work include/linux/entry-common.h:78 [inline] syscall_enter_from_user_mode include/linux/entry-common.h:109 [inline] do_syscall_64+0x42b/0xf80 arch/x86/entry/syscall_64.c:90 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa9d6f8f749 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:00007fa9d7eb60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fa9d71e5fa8 RCX: 00007fa9d6f8f749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa9d71e5fa8 RBP: 00007fa9d71e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fa9d71e6038 R14: 00007ffd414eed50 R15: 00007ffd414eee38 </TASK> --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at [email protected]. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
