INFO: task syz.2.89:6225 blocked for more than 143 seconds. Not tainted 6.14.0-syzkaller-00685-g3ba7dfb8da62 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.89 state:D stack:27552 pid:6225 tgid:6210 ppid:5824 task_flags:0x400040 flags:0x00000004 Call Trace: context_switch kernel/sched/core.c:5373 [inline] __schedule+0x18bc/0x4c40 kernel/sched/core.c:6760 __schedule_loop kernel/sched/core.c:6837 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6852 schedule_preempt_disabled+0x13/0x30 kernel/sched/core.c:6909 __mutex_lock_common kernel/locking/mutex.c:662 [inline] __mutex_lock+0x817/0x1010 kernel/locking/mutex.c:730 blk_trace_startstop+0xa4/0x740 kernel/trace/blktrace.c:700 sg_ioctl_common drivers/scsi/sg.c:1120 [inline] sg_ioctl+0xba2/0x2e10 drivers/scsi/sg.c:1156 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f64ca98d169 RSP: 002b:00007f64cb866038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f64caba6240 RCX: 00007f64ca98d169 RDX: 0000000000000000 RSI: 0000000000001275 RDI: 0000000000000004 RBP: 00007f64caa0e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f64caba6240 R15: 00007ffdbfa22e48 Showing all locks held in the system: 1 lock held by khungtaskd/31: #0: ffffffff8eb39420 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #0: ffffffff8eb39420 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #0: ffffffff8eb39420 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6746 3 locks held by kworker/u8:4/62: #0: ffff888032150948 ((wq_completion)l2tp){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3213 [inline] #0: ffff888032150948 ((wq_completion)l2tp){+.+.}-{0:0}, at: process_scheduled_works+0x98b/0x18e0 kernel/workqueue.c:3319 #1: ffffc9000153fc60 ((work_completion)(&session->del_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3214 [inline] #1: ffffc9000153fc60 ((work_completion)(&session->del_work)){+.+.}-{0:0}, at: process_scheduled_works+0x9c6/0x18e0 kernel/workqueue.c:3319 #2: ffffffff8eb3e800 (rcu_state.barrier_mutex){+.+.}-{4:4}, at: rcu_barrier+0x4c/0x530 kernel/rcu/tree.c:3774 2 locks held by kswapd0/90: 2 locks held by getty/5575: #0: ffff8880317ce0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc9000331b2f0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x616/0x1770 drivers/tty/n_tty.c:2211 3 locks held by syz.2.89/6216: 1 lock held by syz.2.89/6225: #0: ffff888025c3e468 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_startstop+0xa4/0x740 kernel/trace/blktrace.c:700 3 locks held by kworker/u8:9/6541: 2 locks held by syz.0.244/6762: #0: ffff88802575ad48 (&q->debugfs_mutex){+.+.}-{4:4}, at: blk_trace_setup+0xfb/0x1f0 kernel/trace/blktrace.c:631 #1: ffffffff8eb8bf28 (relay_channels_mutex){+.+.}-{4:4}, at: relay_open+0x3cb/0x950 kernel/relay.c:515 ============================================= NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 31 Comm: khungtaskd Not tainted 6.14.0-syzkaller-00685-g3ba7dfb8da62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 nmi_cpu_backtrace+0x49c/0x4d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x198/0x320 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:236 [inline] watchdog+0x1058/0x10a0 kernel/hung_task.c:399 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 90 Comm: kswapd0 Not tainted 6.14.0-syzkaller-00685-g3ba7dfb8da62 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__asan_memset+0x7/0x50 mm/kasan/shadow.c:83 Code: 00 00 e9 bc e6 ff ff 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 56 <53> 48 89 d3 41 89 f6 48 89 fd 48 8b 4c 24 18 48 89 d6 ba 01 00 00 RSP: 0018:ffffc900026de820 EFLAGS: 00000246 RAX: ffffffff84f5cb6b RBX: ffff888035e2d698 RCX: ffff88801d70bc00 RDX: 0000000000000010 RSI: 0000000000000000 RDI: ffff888035e2d5a8 RBP: 0000000000000000 R08: ffff888035e2c72f R09: 0000000000000000 R10: ffff888035e2c720 R11: ffffed1006bc58e6 R12: ffff888035e2d5a8 R13: ffff888035e20000 R14: 00000000000000a8 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4059f78ab8 CR3: 000000002a30a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 000000000000000e DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: INIT_HLIST_NODE include/linux/list.h:937 [inline] hlist_del_init include/linux/list.h:1009 [inline] hash_del include/linux/hashtable.h:107 [inline] update_hashtables lib/842/842_compress.c:433 [inline] sw842_compress+0x28ba/0x4880 lib/842/842_compress.c:550 scomp_acomp_comp_decomp+0x4ac/0x7c0 crypto_acomp_compress include/crypto/acompress.h:251 [inline] zswap_compress mm/zswap.c:962 [inline] zswap_store_page mm/zswap.c:1462 [inline] zswap_store+0xcfe/0x1c20 mm/zswap.c:1571 swap_writepage+0x647/0xce0 mm/page_io.c:278 pageout mm/vmscan.c:696 [inline] shrink_folio_list+0x376a/0x5930 mm/vmscan.c:1402 shrink_inactive_list mm/vmscan.c:2000 [inline] shrink_list mm/vmscan.c:2238 [inline] shrink_lruvec+0x16db/0x2f30 mm/vmscan.c:5749 shrink_node_memcgs mm/vmscan.c:5951 [inline] shrink_node+0x12a4/0x2e10 mm/vmscan.c:5992 kswapd_shrink_node mm/vmscan.c:6807 [inline] balance_pgdat mm/vmscan.c:6999 [inline] kswapd+0x1958/0x2e30 mm/vmscan.c:7264 kthread+0x7a9/0x920 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244