Hello, syzbot found the following issue on: HEAD commit: 4d939780b705 Merge tag 'mm-hotfixes-stable-2024-10-17-16-0.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15f2c240580000 kernel config: https://syzkaller.appspot.com/x/.config?x=cfbd94c114a3d407 dashboard link: https://syzkaller.appspot.com/bug?extid=58928048fd1416f1457c compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/6510e0507f68/disk-4d939780.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/a1bec5c6d200/vmlinux-4d939780.xz kernel image: https://storage.googleapis.com/syzbot-assets/91694f5e7961/bzImage-4d939780.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+58928048fd1416f1457c@xxxxxxxxxxxxxxxxxxxxxxxxx INFO: task syz.2.944:9507 blocked for more than 143 seconds. Not tainted 6.12.0-rc3-syzkaller-00217-g4d939780b705 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.2.944 state:D stack:25744 pid:9507 tgid:9506 ppid:9305 flags:0x00024000 Call Trace: <TASK> context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 schedule_timeout+0xb0/0x310 kernel/time/timer.c:2591 do_wait_for_common kernel/sched/completion.c:95 [inline] __wait_for_common kernel/sched/completion.c:116 [inline] wait_for_common kernel/sched/completion.c:127 [inline] wait_for_completion+0x355/0x620 kernel/sched/completion.c:148 io_wq_exit_workers io_uring/io-wq.c:1249 [inline] io_wq_put_and_exit+0x344/0x720 io_uring/io-wq.c:1277 io_uring_clean_tctx+0x168/0x1e0 io_uring/tctx.c:193 io_uring_cancel_generic+0x76a/0x820 io_uring/io_uring.c:3219 io_uring_files_cancel include/linux/io_uring.h:20 [inline] do_exit+0x6a8/0x28e0 kernel/exit.c:895 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f958877dff9 RSP: 002b:00007f95895d30e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f9588935f88 RCX: 00007f958877dff9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9588935f88 RBP: 00007f9588935f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9588935f8c R13: 0000000000000000 R14: 00007f9588a5f940 R15: 00007f9588a5fa28 </TASK> Showing all locks held in the system: 3 locks held by kworker/u8:1/12: #0: ffff88814bf8f148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88814bf8f148 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000117d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000117d00 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcd2d08 (rtnl_mutex){+.+.}-{3:3}, at: addrconf_dad_work+0xd0/0x16f0 net/ipv6/addrconf.c:4196 1 lock held by khungtaskd/30: #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:337 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:849 [inline] #0: ffffffff8e937de0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x55/0x2a0 kernel/locking/lockdep.c:6720 6 locks held by kworker/u8:3/52: #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline] #0: ffff88801baed948 ((wq_completion)netns){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310 #1: ffffc90000bd7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline] #1: ffffc90000bd7d00 (net_cleanup_work){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310 #2: ffffffff8fcc6210 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x16a/0xcc0 net/core/net_namespace.c:580 #3: ffff8880518ac0e8 (&dev->mutex){....}-{3:3}, at: device_lock include/linux/device.h:1014 [inline] #3: ffff8880518ac0e8 (&dev->mutex){....}-{3:3}, at: devl_dev_lock net/devlink/devl_internal.h:108 [inline] #3: ffff8880518ac0e8 (&dev->mutex){....}-{3:3}, at: devlink_pernet_pre_exit+0x13b/0x440 net/devlink/core.c:506 #4: ffff8880518af250 (&devlink->lock_key#45){+.+.}-{3:3}, at: devl_lock net/devlink/core.c:276 [inline] #4: ffff8880518af250 (&devlink->lock_key#45){+.+.}-{3:3}, at: devl_dev_lock net/devlink/devl_internal.h:109 [inline] #4: ffff8880518af250 (&devlink->lock_key#45){+.+.}-{3:3}, at: devlink_pernet_pre_exit+0x14d/0x440 net/devlink/core.c:506 #5: ffffffff8fcd2d08 (rtnl_mutex){+.+.}-{3:3}, at: nsim_destroy+0x71/0x5c0 drivers/net/netdevsim/netdev.c:773 2 locks held by dhcpcd/4900: 2 locks held by getty/4984: #0: ffff88814d1800a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90002f062f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x6a6/0x1e00 drivers/tty/n_tty.c:2211 1 lock held by iou-wrk-9507/9508: #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-9507/9510: #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-9507/9511: #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-9507/9512: #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 2 locks held by iou-wrk-9507/9513: 1 lock held by iou-wrk-9507/9514: #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-9507/9515: #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by iou-wrk-9507/9516: #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_ring_submit_lock io_uring/io_uring.h:249 [inline] #0: ffff888031f540a8 (&ctx->uring_lock){+.+.}-{3:3}, at: io_provide_buffers+0xd0b/0x1010 io_uring/kbuf.c:580 1 lock held by syz.0.1129/10509: 1 lock held by syz-executor/10878: #0: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:297 [inline] #0: ffffffff8e93d378 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x381/0x830 kernel/rcu/tree_exp.h:976 1 lock held by syz-executor/11012: 1 lock held by syz-executor/11041: 4 locks held by syz-executor/11109: 1 lock held by syz.0.1245/11222: ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 30 Comm: khungtaskd Not tainted 6.12.0-rc3-syzkaller-00217-g4d939780b705 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Call Trace: <TASK> __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:223 [inline] watchdog+0xff4/0x1040 kernel/hung_task.c:379 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 11222 Comm: syz.0.1245 Not tainted 6.12.0-rc3-syzkaller-00217-g4d939780b705 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:preempt_count kernel/rcu/tree.c:4767 [inline] RIP: 0010:rcu_lockdep_current_cpu_online+0x6/0x120 kernel/rcu/tree.c:4771 Code: e9 53 ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 <41> 56 53 65 8b 0d f8 a4 88 7e b0 01 f7 c1 00 00 f0 00 0f 85 d5 00 RSP: 0018:ffffc90003c0f7a8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffff888025388000 RDX: 0000000000000000 RSI: ffffffff8c610180 RDI: ffffffff8c610140 RBP: 0000000000000140 R08: ffffffff820b6d6e R09: 1ffffffff2859300 R10: dffffc0000000000 R11: fffffbfff2859301 R12: 0000000000055529 R13: ffffea0001554a48 R14: ffffffff820b6ca0 R15: ffff88801bf00000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f401994e5a0 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000003 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: <NMI> </NMI> <TASK> rcu_read_lock_held_common kernel/rcu/update.c:113 [inline] rcu_read_lock_held+0x1e/0x50 kernel/rcu/update.c:349 lookup_page_ext mm/page_ext.c:254 [inline] page_ext_get+0x192/0x2a0 mm/page_ext.c:526 __reset_page_owner+0x30/0x430 mm/page_owner.c:290 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 vfree+0x186/0x2e0 mm/vmalloc.c:3361 kcov_put kernel/kcov.c:439 [inline] kcov_close+0x28/0x50 kernel/kcov.c:535 __fput+0x23f/0x880 fs/file_table.c:431 task_work_run+0x24f/0x310 kernel/task_work.c:228 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0xa2f/0x28e0 kernel/exit.c:939 do_group_exit+0x207/0x2c0 kernel/exit.c:1088 get_signal+0x16a3/0x1740 kernel/signal.c:2917 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa6a717dff9 Code: Unable to access opcode bytes at 0x7fa6a717dfcf. RSP: 002b:00007fa6a7f5d0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fa6a7335f88 RCX: 00007fa6a717dff9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa6a7335f88 RBP: 00007fa6a7335f80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa6a7335f8c R13: 0000000000000000 R14: 00007fa6a745f940 R15: 00007fa6a745fa28 </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 report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
