==================================================================
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+0x7be/0xbe0 kernel/time/timer.c:1817
Write of size 8 at addr ffff8881d556f1c8 by task ksoftirqd/1/17

CPU: 1 PID: 17 Comm: ksoftirqd/1 Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x241 lib/dump_stack.c:118
 print_address_description+0x8c/0x600 mm/kasan/report.c:384
 __kasan_report+0xf3/0x120 mm/kasan/report.c:516
 kasan_report+0x30/0x60 mm/kasan/common.c:653
 __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+0x7be/0xbe0 kernel/time/timer.c:1817
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292
 run_ksoftirqd+0x1f/0x30 kernel/softirq.c:603
 smpboot_thread_fn+0x545/0x930 kernel/smpboot.c:165
 kthread+0x2da/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354

Allocated by task 915:
 save_stack mm/kasan/common.c:70 [inline]
 set_track mm/kasan/common.c:78 [inline]
 __kasan_kmalloc+0x171/0x210 mm/kasan/common.c:529
 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+0xd9/0x250 mm/slub.c:2842
 shmem_alloc_inode+0x16/0x30 mm/shmem.c:3719
 alloc_inode fs/inode.c:231 [inline]
 new_inode_pseudo+0x60/0x210 fs/inode.c:966
 new_inode+0x25/0x1d0 fs/inode.c:995
 shmem_get_inode+0x10b/0x620 mm/shmem.c:2252
 shmem_symlink+0x118/0x5f0 mm/shmem.c:3068
 vfs_symlink+0x36c/0x500 fs/namei.c:4276
 do_symlinkat+0x19b/0x400 fs/namei.c:4303
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 17:
 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+0x1b5/0x270 mm/kasan/common.c:487
 slab_free_hook mm/slub.c:1455 [inline]
 slab_free_freelist_hook mm/slub.c:1494 [inline]
 slab_free mm/slub.c:3080 [inline]
 kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096
 __rcu_reclaim kernel/rcu/rcu.h:222 [inline]
 rcu_do_batch+0x492/0xa00 kernel/rcu/tree.c:2167
 rcu_core+0x4c8/0xcb0 kernel/rcu/tree.c:2387
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292

The buggy address belongs to the object at ffff8881d556f090
 which belongs to the cache shmem_inode_cache of size 760
The buggy address is located 312 bytes inside of
 760-byte region [ffff8881d556f090, ffff8881d556f388)
The buggy address belongs to the page:
page:ffffea0007555b00 refcount:1 mapcount:0 mapping:ffff8881f5cfe000 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cfe000
raw: 0000000000000000 0000000000120012 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, 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+0x18f/0x370 mm/page_alloc.c:2171
 get_page_from_freelist+0x2d13/0x2d90 mm/page_alloc.c:3794
 __alloc_pages_nodemask+0x393/0x840 mm/page_alloc.c:4893
 alloc_slab_page+0x39/0x3c0 mm/slub.c:343
 allocate_slab mm/slub.c:1683 [inline]
 new_slab+0x97/0x440 mm/slub.c:1749
 new_slab_objects mm/slub.c:2505 [inline]
 ___slab_alloc+0x2fe/0x490 mm/slub.c:2667
 __slab_alloc+0x62/0xa0 mm/slub.c:2707
 slab_alloc_node mm/slub.c:2792 [inline]
 slab_alloc mm/slub.c:2837 [inline]
 kmem_cache_alloc+0x109/0x250 mm/slub.c:2842
 shmem_alloc_inode+0x16/0x30 mm/shmem.c:3719
 alloc_inode fs/inode.c:231 [inline]
 new_inode_pseudo+0x60/0x210 fs/inode.c:966
 new_inode+0x25/0x1d0 fs/inode.c:995
 shmem_get_inode+0x10b/0x620 mm/shmem.c:2252
 shmem_symlink+0x118/0x5f0 mm/shmem.c:3068
 vfs_symlink+0x36c/0x500 fs/namei.c:4276
 do_symlinkat+0x19b/0x400 fs/namei.c:4303
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
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+0x847/0x950 mm/page_alloc.c:1438
 free_the_page mm/page_alloc.c:4955 [inline]
 __free_pages+0x91/0x140 mm/page_alloc.c:4961
 bpf_check+0x8aeb/0xb3e0 kernel/bpf/verifier.c:9731
 bpf_prog_load kernel/bpf/syscall.c:1724 [inline]
 __do_sys_bpf kernel/bpf/syscall.c:2891 [inline]
 __se_sys_bpf+0x8139/0xbcb0 kernel/bpf/syscall.c:2849
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Memory state around the buggy address:
 ffff8881d556f080: fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d556f100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881d556f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8881d556f200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d556f280: 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 0 P4D 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 17 Comm: ksoftirqd/1 Tainted: G    B             5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f5e27b58 EFLAGS: 00010206
RAX: ffffffff8154e8ca RBX: 0000000000000100 RCX: ffff8881f5e12f40
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881d556f1c0
RBP: ffff8881f5e27d08 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffa118
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d556f1c0
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001f1fef000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 call_timer_fn+0x36/0x390 kernel/time/timer.c:1448
 expire_timers kernel/time/timer.c:1493 [inline]
 __run_timers+0x879/0xbe0 kernel/time/timer.c:1817
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292
 run_ksoftirqd+0x1f/0x30 kernel/softirq.c:603
 smpboot_thread_fn+0x545/0x930 kernel/smpboot.c:165
 kthread+0x2da/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Modules linked in:
CR2: 0000000000000000
---[ end trace 3b6b653106b3660c ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f5e27b58 EFLAGS: 00010206
RAX: ffffffff8154e8ca RBX: 0000000000000100 RCX: ffff8881f5e12f40
RDX: 0000000000000100 RSI: 0000000000000000 RDI: ffff8881d556f1c0
RBP: ffff8881f5e27d08 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffa118
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881d556f1c0
FS:  0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001f1fef000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400