Hello, syzbot found the following issue on: HEAD commit: 3f01e9fed845 Merge tag 'linux-watchdog-6.5-rc2' of git://w.. git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=16c5cd8ca80000 kernel config: https://syzkaller.appspot.com/x/.config?x=150188feee7071a7 dashboard link: https://syzkaller.appspot.com/bug?extid=f527b971b4bdc8e79f9e compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12a86682a80000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1520ab6ca80000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/991cea284d12/disk-3f01e9fe.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/13051b4d971a/vmlinux-3f01e9fe.xz kernel image: https://storage.googleapis.com/syzbot-assets/31cc7c3c2596/bzImage-3f01e9fe.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f527b971b4bdc8e79f9e@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz-executor421:5031 blocked for more than 143 seconds. Not tainted 6.5.0-rc1-syzkaller-00006-g3f01e9fed845 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor421 state:D stack:27728 pid:5031 ppid:5021 flags:0x00004006 Call Trace: <TASK> context_switch kernel/sched/core.c:5381 [inline] __schedule+0xc9a/0x5880 kernel/sched/core.c:6710 schedule+0xde/0x1a0 kernel/sched/core.c:6786 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6845 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa3b/0x1350 kernel/locking/mutex.c:747 __pipe_lock fs/pipe.c:103 [inline] pipe_release+0x4d/0x310 fs/pipe.c:721 __fput+0x40c/0xad0 fs/file_table.c:384 task_work_run+0x16f/0x270 kernel/task_work.c:179 ptrace_notify+0x118/0x140 kernel/signal.c:2372 ptrace_report_syscall include/linux/ptrace.h:411 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline] syscall_exit_work kernel/entry/common.c:252 [inline] syscall_exit_to_user_mode_prepare+0x129/0x220 kernel/entry/common.c:279 __syscall_exit_to_user_mode_work kernel/entry/common.c:284 [inline] syscall_exit_to_user_mode+0xd/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fbe8982b7da RSP: 002b:00007ffd74cb3820 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00007fbe8982b7da RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 000000000000000a R08: 0000000000000000 R09: 00007ffd74d90080 R10: 0000000000000000 R11: 0000000000000293 R12: 000000000000a9f7 R13: 000000000000aa29 R14: 00007fbe898b642c R15: 00007fbe898b6420 </TASK> Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c9a3af0 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:522 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c9a37f0 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:522 1 lock held by khungtaskd/28: #0: ffffffff8c9a4700 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x340 kernel/locking/lockdep.c:6615 2 locks held by getty/4773: #0: ffff88802d33a098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015c02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xf08/0x13f0 drivers/tty/n_tty.c:2187 1 lock held by syz-executor421/5031: #0: ffff888022606868 (&pipe->mutex/1){+.+.}-{3:3}, at: __pipe_lock fs/pipe.c:103 [inline] #0: ffff888022606868 (&pipe->mutex/1){+.+.}-{3:3}, at: pipe_release+0x4d/0x310 fs/pipe.c:721 2 locks held by syz-executor421/5032: ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.5.0-rc1-syzkaller-00006-g3f01e9fed845 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:160 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x344/0x440 kernel/kthread.c:389 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5032 Comm: syz-executor421 Not tainted 6.5.0-rc1-syzkaller-00006-g3f01e9fed845 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023 RIP: 0010:__ip_append_data+0x957/0x3c90 net/ipv4/ip_output.c:1198 Code: 31 ff 29 eb 89 de e8 d8 6d e9 f8 85 db 0f 8e b5 1a 00 00 e8 ab 71 e9 f8 48 8b 44 24 38 41 39 de 41 0f 4e de 41 89 dc 80 38 00 <0f> 85 15 29 00 00 48 8b 44 24 18 48 8b 18 48 8d bb f0 00 00 00 48 RSP: 0018:ffffc90003b9f520 EFLAGS: 00000246 RAX: ffffed100fab0f00 RBX: 0000000000000006 RCX: 0000000000000000 RDX: ffff888019e95940 RSI: ffffffff889b7015 RDI: 0000000000000005 RBP: 000000000000001c R08: 0000000000000005 R09: 0000000000000000 R10: 000000000000057e R11: 0000000000000001 R12: 0000000000000006 R13: dffffc0000000000 R14: 0000000000000006 R15: ffff8880132dd3c0 FS: 00007fbe897e96c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005598ca226780 CR3: 00000000193f8000 CR4: 0000000000350ef0 Call Trace: <NMI> </NMI> <TASK> ip_append_data net/ipv4/ip_output.c:1352 [inline] ip_append_data+0x115/0x1a0 net/ipv4/ip_output.c:1331 udp_sendmsg+0x881/0x2840 net/ipv4/udp.c:1287 inet_sendmsg+0x9d/0xe0 net/ipv4/af_inet.c:830 sock_sendmsg_nosec net/socket.c:725 [inline] sock_sendmsg+0xde/0x190 net/socket.c:748 splice_to_socket+0x964/0xee0 fs/splice.c:882 do_splice_from fs/splice.c:934 [inline] do_splice+0xb8a/0x1ec0 fs/splice.c:1295 __do_splice+0x14e/0x270 fs/splice.c:1373 __do_sys_splice fs/splice.c:1584 [inline] __se_sys_splice fs/splice.c:1566 [inline] __x64_sys_splice+0x19c/0x250 fs/splice.c:1566 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fbe8982c519 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 61 1a 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbe897e9218 EFLAGS: 00000246 ORIG_RAX: 0000000000000113 RAX: ffffffffffffffda RBX: 00007fbe898b6428 RCX: 00007fbe8982c519 RDX: 0000000000000005 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 00007fbe898b6420 R08: 000000000004ffe0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fbe898b642c R13: 00007fbe898834f4 R14: 04000000000003bd R15: 00007ffd74cb3758 </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 syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the bug is already fixed, 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 change bug's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the bug is a duplicate of another bug, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
