INFO: task syz.4.524:9052[ 516.086219][ T37] INFO: task syz.4.524:9052 blocked for more than 143 seconds. Not tainted syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz.4.524 state:D stack:24824 pid:9052 tgid:9052 ppid:8025 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5387 [inline] __schedule+0x1681/0x54c0 kernel/sched/core.c:7188 __schedule_loop kernel/sched/core.c:7267 [inline] rt_mutex_schedule+0x76/0xf0 kernel/sched/core.c:7563 rt_mutex_slowlock_block kernel/locking/rtmutex.c:1662 [inline] __rt_mutex_slowlock kernel/locking/rtmutex.c:1739 [inline] __rt_mutex_slowlock_locked+0x1f28/0x2550 kernel/locking/rtmutex.c:1779 __rwbase_read_lock+0xc3/0x180 kernel/locking/rwbase_rt.c:114 rwbase_read_lock kernel/locking/rwbase_rt.c:147 [inline] __down_read kernel/locking/rwsem.c:1496 [inline] down_read+0x132/0x200 kernel/locking/rwsem.c:1570 filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] do_page_cache_ra mm/readahead.c:333 [inline] page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538 do_sync_mmap_readahead+0x570/0x6a0 mm/filemap.c:3406 filemap_fault+0x70c/0x1310 mm/filemap.c:3555 __do_fault+0x138/0x2a0 mm/memory.c:5458 do_shared_fault mm/memory.c:5957 [inline] do_fault mm/memory.c:6031 [inline] do_pte_missing+0x65b/0x2950 mm/memory.c:4550 handle_pte_fault mm/memory.c:6411 [inline] __handle_mm_fault mm/memory.c:6549 [inline] handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6718 do_user_addr_fault+0xa73/0x1340 arch/x86/mm/fault.c:1334 handle_page_fault arch/x86/mm/fault.c:1474 [inline] exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7fdf2cf8bc98 RSP: 002b:00007ffea5c7fd48 EFLAGS: 00010202 RAX: 0000200000000040 RBX: 0000000000000004 RCX: 0030626c6c756e2f RDX: 000000000000000c RSI: 6c756e2f7665642f RDI: 0000200000000040 RBP: fffffffffffffffe R08: 0000001b30c20000 R09: 0000000000000001 R10: 7ffffffffffffff3 R11: 0000000000000009 R12: 00007ffea5c7fe70 R13: 00007fdf2d235fac R14: 0000000000055fa8 R15: 00007fdf2d235fa0 Showing all locks held in the system: 1 lock held by khungtaskd/37: #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8dfc8140 (rcu_read_lock){....}-{1:3}, at: debug_show_all_locks+0x2e/0x180 kernel/locking/lockdep.c:6775 3 locks held by kworker/u8:5/70: #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88801a074138 ((wq_completion)events_unbound){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc9000155fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc9000155fc40 ((linkwatch_work).work){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:313 3 locks held by kworker/u8:6/213: #0: ffff88803204f138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3277 [inline] #0: ffff88803204f138 ((wq_completion)ipv6_addrconf){+.+.}-{0:0}, at: process_scheduled_works+0xa35/0x1860 kernel/workqueue.c:3385 #1: ffffc90003bd7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3278 [inline] #1: ffffc90003bd7c40 ((work_completion)(&(&ifa->dad_work)->work)){+.+.}-{0:0}, at: process_scheduled_works+0xa70/0x1860 kernel/workqueue.c:3385 #2: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #2: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: addrconf_dad_work+0x124/0x1680 net/ipv6/addrconf.c:4206 7 locks held by kworker/u8:10/2249: 2 locks held by dhcpcd/5253: #0: ffff888039b32928 (nlk_cb_mutex-ROUTE){+.+.}-{4:4}, at: __netlink_dump_start+0xfe/0x7e0 net/netlink/af_netlink.c:2404 #1: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_dumpit+0x92/0x200 net/core/rtnetlink.c:6863 2 locks held by getty/5340: #0: ffff88803614e0a0 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x25/0x70 drivers/tty/tty_ldisc.c:243 #1: ffffc90003cbe2e0 (&ldata->atomic_read_lock){+.+.}-{4:4}, at: n_tty_read+0x462/0x13a0 drivers/tty/n_tty.c:2211 11 locks held by kworker/0:5/5700: 4 locks held by kworker/0:2H/8196: 2 locks held by syz.9.509/8971: 1 lock held by syz.4.524/9052: #0: ffff888025eaa598 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #0: ffff888025eaa598 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline] #0: ffff888025eaa598 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538 1 lock held by syz.3.556/9973: #0: ffff888025eaa598 (mapping.invalidate_lock){++++}-{4:4}, at: filemap_invalidate_lock_shared include/linux/fs.h:1094 [inline] #0: ffff888025eaa598 (mapping.invalidate_lock){++++}-{4:4}, at: do_page_cache_ra mm/readahead.c:333 [inline] #0: ffff888025eaa598 (mapping.invalidate_lock){++++}-{4:4}, at: page_cache_ra_order+0x2a5/0x490 mm/readahead.c:538 1 lock held by syz-executor/10180: #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: inet6_rtm_newaddr+0x65f/0xe30 net/ipv6/addrconf.c:5039 1 lock held by syz-executor/10273: #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4108 1 lock held by syz-executor/10376: #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_net_lock include/linux/rtnetlink.h:130 [inline] #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: inet_rtm_newaddr+0x404/0x1ad0 net/ipv4/devinet.c:978 2 locks held by syz-executor/10552: #0: ffffffff8ea96708 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_lock_acquire include/linux/rcupdate.h:300 [inline] #0: ffffffff8ea96708 (&ops->srcu#2){.+.+}-{0:0}, at: rcu_read_lock include/linux/rcupdate.h:838 [inline] #0: ffffffff8ea96708 (&ops->srcu#2){.+.+}-{0:0}, at: rtnl_link_ops_get+0x23/0x250 net/core/rtnetlink.c:570 #1: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #1: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #1: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4108 1 lock held by syz-executor/10658: #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_lock net/core/rtnetlink.c:80 [inline] #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_nets_lock net/core/rtnetlink.c:341 [inline] #0: ffffffff8f356b38 (rtnl_mutex){+.+.}-{4:4}, at: rtnl_newlink+0x883/0x1bb0 net/core/rtnetlink.c:4108 ============================================= NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 37 Comm: khungtaskd Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120 nmi_cpu_backtrace+0x274/0x2d0 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x17a/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:162 [inline] __sys_info lib/sys_info.c:157 [inline] sys_info+0x135/0x170 lib/sys_info.c:165 check_hung_uninterruptible_tasks kernel/hung_task.c:353 [inline] watchdog+0xfd3/0x1030 kernel/hung_task.c:561 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 8971 Comm: syz.9.509 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x0/0xa0 kernel/kcov.c:320 Code: 00 48 89 7c 0a 10 48 89 74 0a 18 48 89 44 0a 20 c3 cc cc cc cc cc 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 04 24 65 48 8b 0d 68 f9 a5 10 65 44 8b 05 88 f9 RSP: 0018:ffffc90005a67a10 EFLAGS: 00000246 RAX: ffffffff847d3234 RBX: ffffffff847d31b5 RCX: ffff88803f2abd80 RDX: 0000000000000002 RSI: 0000000000000008 RDI: 0000000000000000 RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff94000093749 R12: ffffea000000000f R13: dffffc0000000000 R14: 00000000000126e9 R15: ffff88813fe4a040 FS: 00007f6df8d9e6c0(0000) GS:ffff888126179000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f041f62ae18 CR3: 0000000070562000 CR4: 00000000003526f0 Call Trace: pfn_valid+0x236/0x4c0 include/linux/mmzone.h:2290 bvec_try_merge_page+0xc2/0x280 block/bio.c:947 bio_add_page+0x2e0/0x6f0 block/bio.c:1055 bio_add_folio+0x64/0x90 block/bio.c:1099 __blkdev_issue_zero_pages+0x2da/0x3f0 block/blk-lib.c:209 blkdev_issue_zero_pages block/blk-lib.c:231 [inline] blkdev_issue_zeroout+0x45e/0x600 block/blk-lib.c:312 blkdev_fallocate+0x472/0x550 block/fops.c:934 vfs_fallocate+0x672/0x7f0 fs/open.c:338 ksys_fallocate fs/open.c:362 [inline] __do_sys_fallocate fs/open.c:367 [inline] __se_sys_fallocate fs/open.c:365 [inline] __x64_sys_fallocate+0xc0/0x110 fs/open.c:365 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6dfab4cdd9 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:00007f6df8d9e028 EFLAGS: 00000246 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007f6dfadc5fa0 RCX: 00007f6dfab4cdd9 RDX: 0000000100000000 RSI: 0000000000000011 RDI: 0000000000000004 RBP: 00007f6dfabe2d69 R08: 0000000000000000 R09: 0000000000000000 R10: 001000000007c000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f6dfadc6038 R14: 00007f6dfadc5fa0 R15: 00007ffdcbd70df8