==================================================================
BUG: KASAN: use-after-free in __hlist_del include/linux/list.h:791 [inline]
BUG: KASAN: use-after-free in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: use-after-free in expire_timers kernel/time/timer.c:1482 [inline]
BUG: KASAN: use-after-free in __run_timers+0x759/0xb60 kernel/time/timer.c:1817
Write of size 8 at addr ffff8881d519f1c8 by task ksoftirqd/0/10

CPU: 0 PID: 10 Comm: ksoftirqd/0 Not tainted 5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 __dump_stack+0x1e/0x20 lib/dump_stack.c:77
 dump_stack+0x15b/0x1b8 lib/dump_stack.c:118
 print_address_description+0x8d/0x4c0 mm/kasan/report.c:384
 __kasan_report+0xef/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:137
 __hlist_del include/linux/list.h:791 [inline]
 detach_timer kernel/time/timer.c:824 [inline]
 expire_timers kernel/time/timer.c:1482 [inline]
 __run_timers+0x759/0xb60 kernel/time/timer.c:1817
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x236/0x660 kernel/softirq.c:292
 run_ksoftirqd+0x23/0x30 kernel/softirq.c:603
 smpboot_thread_fn+0x474/0x850 kernel/smpboot.c:165
 kthread+0x31e/0x3a0 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354

Allocated by task 164:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x162/0x200 mm/kasan/common.c:529
 kasan_slab_alloc+0x12/0x20 mm/kasan/common.c:537
 slab_post_alloc_hook mm/slab.h:584 [inline]
 slab_alloc_node mm/slub.c:2829 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0xe2/0x270 mm/slub.c:2842
 getname_flags+0xb9/0x500 fs/namei.c:141
 getname+0x19/0x20 fs/namei.c:212
 do_sys_open+0x26c/0x5d0 fs/open.c:1117
 __do_sys_openat fs/open.c:1150 [inline]
 __se_sys_openat fs/open.c:1144 [inline]
 __x64_sys_openat+0xa2/0xb0 fs/open.c:1144
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 164:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 kasan_set_free_info mm/kasan/common.c:345 [inline]
 __kasan_slab_free+0x1c3/0x280 mm/kasan/common.c:487
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:496
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook+0xb7/0x180 mm/slub.c:1494
 slab_free mm/slub.c:3080 [inline]
 kmem_cache_free+0x10c/0x2c0 mm/slub.c:3096
 putname+0xfe/0x150 fs/namei.c:262
 do_sys_open+0x520/0x5d0 fs/open.c:1132
 __do_sys_openat fs/open.c:1150 [inline]
 __se_sys_openat fs/open.c:1144 [inline]
 __x64_sys_openat+0xa2/0xb0 fs/open.c:1144
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

The buggy address belongs to the object at ffff8881d519e600
 which belongs to the cache names_cache of size 4096
The buggy address is located 3016 bytes inside of
 4096-byte region [ffff8881d519e600, ffff8881d519f600)
The buggy address belongs to the page:
page:ffffea0007546600 refcount:1 mapcount:0 mapping:ffff8881f5d00280 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5d00280
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL)
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook mm/page_alloc.c:2165 [inline]
 prep_new_page+0x35e/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x1296/0x1310 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x202/0x4b0 mm/page_alloc.c:4894
 alloc_slab_page+0x3c/0x3b0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x93/0x420 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x29e/0x420 mm/slub.c:2667
 __slab_alloc+0x63/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0x12c/0x270 mm/slub.c:2842
 getname_flags+0xb9/0x500 fs/namei.c:141
 user_path_at_empty+0x2f/0x50 fs/namei.c:2703
 user_path_at include/linux/namei.h:49 [inline]
 vfs_statx+0x116/0x200 fs/stat.c:187
 vfs_fstatat include/linux/fs.h:3389 [inline]
 __do_sys_newfstatat fs/stat.c:367 [inline]
 __se_sys_newfstatat+0xcc/0x350 fs/stat.c:361
 __x64_sys_newfstatat+0x9b/0xb0 fs/stat.c:361
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1176 [inline]
 __free_pages_ok+0x7e4/0x910 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4956 [inline]
 __free_pages+0x8c/0x110 mm/page_alloc.c:4962
 free_thread_stack kernel/fork.c:299 [inline]
 release_task_stack kernel/fork.c:439 [inline]
 put_task_stack+0x21b/0x260 kernel/fork.c:450
 finish_task_switch+0x245/0x590 kernel/sched/core.c:3481
 context_switch kernel/sched/core.c:3613 [inline]
 __schedule+0xa57/0x12a0 kernel/sched/core.c:4309
 schedule+0x12d/0x1c0 kernel/sched/core.c:4377
 freezable_schedule include/linux/freezer.h:172 [inline]
 do_nanosleep+0x1b1/0x600 kernel/time/hrtimer.c:1942
 hrtimer_nanosleep+0x213/0x440 kernel/time/hrtimer.c:1995
 common_nsleep+0x2c/0x40 kernel/time/posix-timers.c:1203
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1231 [inline]
 __se_sys_clock_nanosleep+0x305/0x3a0 kernel/time/posix-timers.c:1208
 __x64_sys_clock_nanosleep+0x9b/0xb0 kernel/time/posix-timers.c:1208
 do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881d519f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d519f100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881d519f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8881d519f200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d519f280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1c6300067 P4D 1c6300067 PUD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 10 Comm: ksoftirqd/0 Tainted: G    B             5.4.292-syzkaller-00021-gcd8e74fa0fa3 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0000:ffff8881f5dd7bd0 EFLAGS: 00010206
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881f5dc1f80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881d519f1c0
RBP: ffff8881f5dd7c10 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ebbaf74 R11: 1ffff1103ebbaf74 R12: 00000000ffffba80
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d519f1c0
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001db15b000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000602
Call Trace:
 call_timer_fn+0x3c/0x380 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x81d/0xb60 kernel/time/timer.c:1817
 run_timer_softirq+0x6a/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x236/0x660 kernel/softirq.c:292
 run_ksoftirqd+0x23/0x30 kernel/softirq.c:603
 smpboot_thread_fn+0x474/0x850 kernel/smpboot.c:165
 kthread+0x31e/0x3a0 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Modules linked in:
CR2: 0000000000000000
---[ end trace 8cb5887f5e7103bb ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0000:ffff8881f5dd7bd0 EFLAGS: 00010206
RAX: ffffffff8150a590 RBX: 0000000000000100 RCX: ffff8881f5dc1f80
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881d519f1c0
RBP: ffff8881f5dd7c10 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ebbaf74 R11: 1ffff1103ebbaf74 R12: 00000000ffffba80
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d519f1c0
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001db15b000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000602