INFO: task syz.5.2231:14456 blocked for more than 143 seconds. Tainted: G L syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.5.2231 state:D stack:28160 pid:14456 tgid:14455 ppid:9252 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0x1585/0x5340 kernel/sched/core.c:6907 __schedule_loop kernel/sched/core.c:6989 [inline] schedule+0x164/0x360 kernel/sched/core.c:7004 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:7061 __mutex_lock_common kernel/locking/mutex.c:692 [inline] __mutex_lock+0x7fe/0x1300 kernel/locking/mutex.c:776 bdev_open+0xe0/0xd30 block/bdev.c:961 blkdev_open+0x470/0x610 block/fops.c:698 do_dentry_open+0x785/0x14e0 fs/open.c:949 vfs_open+0x3b/0x340 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x2e08/0x3860 fs/namei.c:4830 do_file_open+0x23e/0x4a0 fs/namei.c:4859 do_sys_openat2+0x113/0x200 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1383 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: 0033:0x7fcd8375cece RSP: 002b:00007fcd84691b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fcd846926c0 RCX: 00007fcd8375cece RDX: 0000000000000002 RSI: 00007fcd84691c00 RDI: ffffffffffffff9c RBP: 00007fcd84691c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fcd83a16038 R14: 00007fcd83a15fa0 R15: 00007ffe0f23dd28 Showing all locks held in the system: 3 locks held by kworker/0:0/9: #0: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655 #1: ffff8880b8624588 (psi_seq){-.-.}-{0:0}, at: psi_task_switch+0x53/0x880 kernel/sched/psi.c:933 #2: ffff8880446fa240 (&data->fib_lock){+.+.}-{4:4}, at: nsim_fib_event_work+0x202/0x3d0 drivers/net/netdevsim/fib.c:1490 1 lock held by khungtaskd/31: #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:312 [inline] #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:850 [inline] #0: ffffffff8e7602e0 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 1 lock held by klogd/5189: #0: ffff8880b863ade0 (&rq->__lock){-.-.}-{2:2}, at: raw_spin_rq_lock_nested+0xb6/0x150 kernel/sched/core.c:655 2 locks held by getty/5587: #0: ffff88803846a0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000332b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x45c/0x13c0 drivers/tty/n_tty.c:2211 1 lock held by udevd/5838: #0: ffff888027922358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961 1 lock held by udevd/7857: 1 lock held by syz.5.2231/14456: #0: ffff888027922358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:961 3 locks held by syz.9.2615/16690: 3 locks held by syz.9.2615/16695: #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline] #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 #1: ffff88807b342320 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88807b342320 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3492 #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: acomp_ctx_get_cpu_lock mm/zswap.c:834 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:865 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1416 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store+0xc0c/0x1f80 mm/zswap.c:1527 4 locks held by syz.9.2615/16696: 2 locks held by syz.9.2615/16699: #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline] #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 #1: ffff88807b345068 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88807b345068 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3492 2 locks held by syz.9.2615/16701: 3 locks held by syz.9.2615/16702: #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline] #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 #1: ffff888034321630 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888034321630 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3492 #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: acomp_ctx_get_cpu_lock mm/zswap.c:834 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:865 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1416 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store+0xc0c/0x1f80 mm/zswap.c:1527 3 locks held by syz.9.2615/16704: #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline] #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 #1: ffff88802c8670c0 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88802c8670c0 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3492 #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: acomp_ctx_get_cpu_lock mm/zswap.c:834 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:865 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1416 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store+0xc0c/0x1f80 mm/zswap.c:1527 3 locks held by syz.9.2615/16705: #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline] #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 #1: ffff88802c860fb8 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff88802c860fb8 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3492 #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: acomp_ctx_get_cpu_lock mm/zswap.c:834 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:865 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1416 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store+0xc0c/0x1f80 mm/zswap.c:1527 3 locks held by syz.9.2615/16707: #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline] #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 #1: ffff888078ccf738 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888078ccf738 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3492 #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: acomp_ctx_get_cpu_lock mm/zswap.c:834 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:865 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1416 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store+0xc0c/0x1f80 mm/zswap.c:1527 3 locks held by syz.9.2615/16708: #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline] #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 #1: ffff888078ccdd58 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888078ccdd58 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3492 #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: acomp_ctx_get_cpu_lock mm/zswap.c:834 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:865 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1416 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store+0xc0c/0x1f80 mm/zswap.c:1527 4 locks held by syz.9.2615/16710: 2 locks held by syz.9.2615/16714: #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline] #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 #1: ffff8880523a5d58 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff8880523a5d58 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3492 3 locks held by syz.9.2615/16717: #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: do_coredump fs/coredump.c:1127 [inline] #0: ffff88806c37c420 (sb_writers#5){.+.+}-{0:0}, at: vfs_coredump+0x36a9/0x4280 fs/coredump.c:1201 #1: ffff888055f0c378 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: inode_lock include/linux/fs.h:1028 [inline] #1: ffff888055f0c378 (&sb->s_type->i_mutex_key#16){++++}-{4:4}, at: shmem_file_write_iter+0x7f/0x120 mm/shmem.c:3492 #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: acomp_ctx_get_cpu_lock mm/zswap.c:834 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_compress mm/zswap.c:865 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store_page mm/zswap.c:1416 [inline] #2: ffffe8ffffd267b0 (&per_cpu_ptr(pool->acomp_ctx, cpu)->mutex){+.+.}-{4:4}, at: zswap_store+0xc0c/0x1f80 mm/zswap.c:1527 1 lock held by syz.0.2666/16928: #0: ffffffff8e766440 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x580 kernel/rcu/tree.c:3828 2 locks held by sed/16982: ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:161 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:346 [inline] watchdog+0xfd9/0x1030 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 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 16982 Comm: sed Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:194 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x70 kernel/kcov.c:217 Code: 68 ed 56 11 65 8b 15 89 ed 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 91 38 16 00 00 48 8b 32 48 8d 7e 01 8b 89 34 RSP: 0000:ffffc90005ee77e0 EFLAGS: 00000046 RAX: ffffffff81b9d825 RBX: 0000000000000000 RCX: ffff8880320ebc80 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff81787970 RBP: ffffc90005ee7950 R08: ffffffff9011c2b7 R09: 1ffffffff2023856 R10: dffffc0000000000 R11: fffffbfff2023857 R12: ffff8880b873bf80 R13: dffffc0000000000 R14: ffffffff81787970 R15: 0000000000000000 FS: 00007fbcdb9aac80(0000) GS:ffff888125557000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbcdbc42000 CR3: 000000006a3e2000 CR4: 00000000003526f0 Call Trace: trace_csd_function_exit+0x15/0x210 include/trace/events/csd.h:64 csd_do_func kernel/smp.c:137 [inline] smp_call_function_many_cond+0xf1c/0x12c0 kernel/smp.c:868 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:57 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x5c3/0x10c0 arch/x86/mm/tlb.c:1472 flush_tlb_page arch/x86/include/asm/tlbflush.h:323 [inline] ptep_clear_flush+0x120/0x170 mm/pgtable-generic.c:103 wp_page_copy mm/memory.c:3846 [inline] do_wp_page+0x4129/0x5a00 mm/memory.c:4241 handle_pte_fault mm/memory.c:6333 [inline] __handle_mm_fault mm/memory.c:6455 [inline] handle_mm_fault+0x1520/0x3310 mm/memory.c:6624 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fbcdbd2c4ac Code: d0 48 83 c1 08 4c 01 10 48 8d 78 08 48 39 f1 73 35 48 8b 01 a8 01 74 e6 48 d1 e8 48 89 fa 74 16 66 0f 1f 44 00 00 a8 01 74 03 <4c> 01 12 48 83 c2 08 48 d1 e8 75 f0 48 83 c1 08 48 81 c7 f8 01 00 RSP: 002b:00007ffc8e241af0 EFLAGS: 00010202 RAX: 00000fffffffe3ff RBX: 0000000000000000 RCX: 00007fbcdba9a348 RDX: 00007fbcdbc42000 RSI: 00007fbcdba9a400 RDI: 00007fbcdbc41fd0 RBP: 00007ffc8e241c10 R08: 0000000000000000 R09: 00007fbcdbd54da0 R10: 00007fbcdba73000 R11: 0000000000000203 R12: 0000000000000001 R13: 0000000000000000 R14: 00007fbcdbd155f0 R15: 0000000000000000