INFO: task syz.9.2576:8213 blocked for more than 122 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.9.2576 state:D stack:0 pid:8213 tgid:8212 ppid:8039 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 request_wait_answer fs/fuse/dev.c:476 [inline] __fuse_request_send fs/fuse/dev.c:491 [inline] __fuse_simple_request+0xdb1/0x1980 fs/fuse/dev.c:586 fuse_simple_request fs/fuse/fuse_i.h:1248 [inline] fuse_send_open fs/fuse/file.c:53 [inline] fuse_file_open+0x47c/0x910 fs/fuse/file.c:161 fuse_do_open fs/fuse/file.c:190 [inline] fuse_open+0x83d/0x1ba0 fs/fuse/file.c:293 do_dentry_open+0x978/0x1510 fs/open.c:960 vfs_open+0x86/0x230 fs/open.c:1090 do_open fs/namei.c:3774 [inline] path_openat+0x2b6c/0x34b0 fs/namei.c:3933 do_filp_open+0x1c6/0x3e0 fs/namei.c:3960 do_sys_openat2+0x12c/0x1c0 fs/open.c:1438 do_sys_open fs/open.c:1453 [inline] __do_sys_openat fs/open.c:1469 [inline] __se_sys_openat fs/open.c:1464 [inline] __x64_sys_openat+0x13a/0x170 fs/open.c:1464 x64_sys_call+0xe69/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:258 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f79d238ebe9 RSP: 002b:00007f79d318a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f79d25c5fa0 RCX: 00007f79d238ebe9 RDX: 0000000000040042 RSI: 0000200000000240 RDI: ffffffffffffff9c RBP: 00007f79d2411e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f79d25c6038 R14: 00007f79d25c5fa0 R15: 00007ffd11fc6a88 NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 0dd0103ec329b4c3ce546fdd10bdf8515cdb9785 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: __dump_stack+0x21/0x30 lib/dump_stack.c:94 dump_stack_lvl+0x10c/0x190 lib/dump_stack.c:120 dump_stack+0x19/0x20 lib/dump_stack.c:129 nmi_cpu_backtrace+0x2bf/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x142/0x2c0 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:41 trigger_all_cpu_backtrace include/linux/nmi.h:158 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:267 [inline] watchdog+0xd8f/0xed0 kernel/hung_task.c:423 kthread+0x2c7/0x370 kernel/kthread.c:389 ret_from_fork+0x64/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 14085 Comm: syz.8.4493 Not tainted syzkaller #0 0dd0103ec329b4c3ce546fdd10bdf8515cdb9785 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x35/0x70 kernel/kcov.c:217 Code: 08 65 48 8b 0c 25 00 eb 04 00 65 8b 15 2c 08 7f 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 ec 0b 00 00 00 74 2c <8b> 91 c8 0b 00 00 83 fa 02 75 21 48 8b 91 d0 0b 00 00 48 8b 32 48 RSP: 0018:ffffc9000477f4d8 EFLAGS: 00000246 RAX: ffffffff81d9416b RBX: ffffc9000477f7a0 RCX: ffff888119465f00 RDX: 0000000000000000 RSI: f800000000000000 RDI: f800000000000000 RBP: ffffc9000477f4d8 R08: 0000000000000003 R09: 0000000000000004 R10: 0000000000000000 R11: ffffffff81d94100 R12: dffffc0000000000 R13: 000020000025f000 R14: f800000000000000 R15: f800000000000000 FS: 00007fea08f216c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9d73b94198 CR3: 00000001134b4000 CR4: 00000000003526b0 Call Trace: guard_install_pte_entry+0x6b/0xd0 mm/madvise.c:1126 walk_pte_range_inner mm/pagewalk.c:50 [inline] walk_pte_range mm/pagewalk.c:88 [inline] walk_pmd_range mm/pagewalk.c:156 [inline] walk_pud_range mm/pagewalk.c:226 [inline] walk_p4d_range mm/pagewalk.c:264 [inline] walk_pgd_range+0x12e5/0x1ba0 mm/pagewalk.c:305 __walk_page_range mm/pagewalk.c:412 [inline] walk_page_range_mm+0x5e3/0x810 mm/pagewalk.c:505 madvise_guard_install mm/madvise.c:1197 [inline] madvise_vma_behavior+0x15b0/0x2d40 mm/madvise.c:1367 madvise_walk_vmas+0x1b1/0x2e0 mm/madvise.c:1545 do_madvise+0x4b7/0x960 mm/madvise.c:1738 __do_sys_madvise mm/madvise.c:1754 [inline] __se_sys_madvise mm/madvise.c:1752 [inline] __x64_sys_madvise+0xae/0xc0 mm/madvise.c:1752 x64_sys_call+0x20c3/0x2ee0 arch/x86/include/generated/asm/syscalls_64.h:29 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x58/0xf0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fea0818ebe9 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:00007fea08f21038 EFLAGS: 00000246 ORIG_RAX: 000000000000001c RAX: ffffffffffffffda RBX: 00007fea083c5fa0 RCX: 00007fea0818ebe9 RDX: 0000000000000066 RSI: 0000000000600722 RDI: 0000200000000000 RBP: 00007fea08211e19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fea083c6038 R14: 00007fea083c5fa0 R15: 00007ffd93608868