R13: 00007fc63654c038 R14: 00007fc63654bfa0 R15: 00007ffcfe93fe58 watchdog: BUG: soft lockup - CPU#1 stuck for 287s! [syz.4.1386:5721] Modules linked in: CPU: 1 PID: 5721 Comm: syz.4.1386 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x36/0x60 kernel/kcov.c:206 Code: 70 a0 98 7e 65 8b 15 71 a0 98 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 5c 0b 00 00 00 74 2c 8b 91 38 0b 00 00 <83> fa 02 75 21 48 8b 91 40 0b 00 00 48 8b 32 48 8d 7e 01 8b 89 3c RSP: 0018:ffffc90000ad6eb8 EFLAGS: 00000246 RAX: ffffffff83da8798 RBX: 00000000ffff0000 RCX: ffff88810feba780 RDX: 0000000000000002 RSI: 00000000ffff0000 RDI: ffff888114e26000 RBP: ffffc90000ad6eb8 R08: ffff88810feba780 R09: 0000000000000002 R10: 00000000ffffffff R11: 0000000000000002 R12: 00000000fffffff1 R13: ffff8881455208cc R14: ffff888114e26000 R15: ffff888145520840 FS: 00007fc634d2d6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2f1f36 CR3: 0000000147214000 CR4: 00000000003526a0 Call Trace: qdisc_lookup+0x18/0x4e0 net/sched/sch_api.c:299 qdisc_tree_reduce_backlog+0x111/0x340 net/sched/sch_api.c:784 fq_change+0xc5d/0x1250 net/sched/sch_fq.c:915 fq_init+0x3e3/0x5d0 net/sched/sch_fq.c:963 qdisc_create+0x803/0x11b0 net/sched/sch_api.c:1256 tc_modify_qdisc+0x8ad/0x1570 net/sched/sch_api.c:-1 rtnetlink_rcv_msg+0xa4b/0xce0 net/core/rtnetlink.c:5650 netlink_rcv_skb+0x1f5/0x440 net/netlink/af_netlink.c:2511 rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5668 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x876/0xa40 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x879/0xb80 net/netlink/af_netlink.c:1922 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2435 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2489 __sys_sendmsg net/socket.c:2518 [inline] __do_sys_sendmsg net/socket.c:2527 [inline] __se_sys_sendmsg net/socket.c:2525 [inline] __x64_sys_sendmsg+0x206/0x2f0 net/socket.c:2525 x64_sys_call+0x4b/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:47 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fc6362d2629 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fc634d2d028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007fc63654bfa0 RCX: 00007fc6362d2629 RDX: 0000000020040080 RSI: 0000200000001200 RDI: 0000000000000003 RBP: 00007fc636368b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc63654c038 R14: 00007fc63654bfa0 R15: 00007ffcfe93fe58 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle+0xf/0x20 arch/x86/kernel/process.c:729