==================================================================
BUG: KASAN: slab-out-of-bounds in __hlist_del include/linux/list.h:791 [inline]
BUG: KASAN: slab-out-of-bounds in detach_timer kernel/time/timer.c:824 [inline]
BUG: KASAN: slab-out-of-bounds in expire_timers kernel/time/timer.c:1452 [inline]
BUG: KASAN: slab-out-of-bounds in __run_timers+0x7be/0xbe0 kernel/time/timer.c:1787
Write of size 8 at addr ffff8881e05ab1c8 by task syz-executor.0/4800

CPU: 0 PID: 4800 Comm: syz-executor.0 Not tainted 5.4.265-syzkaller-00009-g43a5ead9254d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Call Trace:
 <IRQ>
 __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:1452 [inline]
 __run_timers+0x7be/0xbe0 kernel/time/timer.c:1787
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1800
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x195/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:538 [inline]
 smp_apic_timer_interrupt+0x11a/0x460 arch/x86/kernel/apic/apic.c:1149
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>

Allocated by task 4777:
 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]
 __kmalloc_track_caller+0x100/0x2b0 mm/slub.c:4449
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xb4/0x4d0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1080 [inline]
 alloc_skb_with_frags+0x92/0x550 net/core/skbuff.c:5827
 sock_alloc_send_pskb+0x831/0x950 net/core/sock.c:2276
 unix_stream_sendmsg+0x581/0xe80 net/unix/af_unix.c:1911
 sock_sendmsg_nosec net/socket.c:638 [inline]
 __sock_sendmsg net/socket.c:650 [inline]
 ____sys_sendmsg+0x5ac/0x8f0 net/socket.c:2304
 ___sys_sendmsg net/socket.c:2358 [inline]
 __sys_sendmsg+0x28b/0x380 net/socket.c:2404
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

Freed by task 4781:
 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]
 kfree+0x123/0x370 mm/slub.c:4071
 skb_release_all net/core/skbuff.c:675 [inline]
 __kfree_skb net/core/skbuff.c:689 [inline]
 consume_skb+0xa5/0x2a0 net/core/skbuff.c:849
 unix_stream_read_generic+0x1ad7/0x2060 net/unix/af_unix.c:2441
 unix_stream_recvmsg+0x166/0x1e0 net/unix/af_unix.c:2499
 ____sys_recvmsg net/socket.c:2536 [inline]
 ___sys_recvmsg+0x6a7/0xa60 net/socket.c:2577
 __sys_recvmsg net/socket.c:2624 [inline]
 __do_sys_recvmsg net/socket.c:2634 [inline]
 __se_sys_recvmsg net/socket.c:2631 [inline]
 __x64_sys_recvmsg+0x1f4/0x2c0 net/socket.c:2631
 do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x5c/0xc1

The buggy address belongs to the object at ffff8881e05aa000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 456 bytes to the right of
 4096-byte region [ffff8881e05aa000, ffff8881e05ab000)
The buggy address belongs to the page:
page:ffffea0007816a00 refcount:1 mapcount:0 mapping:ffff8881f5c0c280 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5c0c280
raw: 0000000000000000 0000000000040004 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+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:4891
 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]
 __kmalloc_track_caller+0x16d/0x2b0 mm/slub.c:4449
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xb4/0x4d0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1080 [inline]
 alloc_skb_with_frags+0x92/0x550 net/core/skbuff.c:5827
 sock_alloc_send_pskb+0x831/0x950 net/core/sock.c:2276
 unix_stream_sendmsg+0x581/0xe80 net/unix/af_unix.c:1911
 sock_sendmsg_nosec net/socket.c:638 [inline]
 __sock_sendmsg net/socket.c:650 [inline]
 ____sys_sendmsg+0x5ac/0x8f0 net/socket.c:2304
 ___sys_sendmsg net/socket.c:2358 [inline]
 __sys_sendmsg+0x28b/0x380 net/socket.c:2404
 do_syscall_64+0xca/0x1c0 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_pcp_prepare mm/page_alloc.c:1233 [inline]
 free_unref_page_prepare+0x297/0x380 mm/page_alloc.c:3085
 free_unref_page mm/page_alloc.c:3134 [inline]
 free_the_page mm/page_alloc.c:4951 [inline]
 __free_pages+0xaf/0x140 mm/page_alloc.c:4959
 pcpu_free_pages mm/percpu-vm.c:64 [inline]
 pcpu_depopulate_chunk mm/percpu-vm.c:328 [inline]
 pcpu_balance_workfn+0x940/0x1450 mm/percpu.c:1865
 process_one_work+0x765/0xd20 kernel/workqueue.c:2290
 worker_thread+0xaef/0x1470 kernel/workqueue.c:2436
 kthread+0x2da/0x360 kernel/kthread.c:288
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354

Memory state around the buggy address:
 ffff8881e05ab080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881e05ab100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8881e05ab180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                              ^
 ffff8881e05ab200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881e05ab280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor instruction fetch in kernel mode
#PF: error_code(0x0010) - not-present page
PGD 1e796c067 P4D 1e796c067 PUD 1e8bfa067 PMD 0 
Oops: 0010 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 4800 Comm: syz-executor.0 Tainted: G    B             5.4.265-syzkaller-00009-g43a5ead9254d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010202
RAX: ffffffff8154e38a RBX: 0000000000000101 RCX: ffff8881f39ebf00
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e05ab1c0
RBP: ffff8881f6e09ec8 R08: ffffffff8154dfce R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffca20
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e05ab1c0
FS:  00007f7a43cda6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001e796d000 CR4: 00000000003406b0
DR0: 0001000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 call_timer_fn+0x36/0x390 kernel/time/timer.c:1418
 expire_timers kernel/time/timer.c:1463 [inline]
 __run_timers+0x879/0xbe0 kernel/time/timer.c:1787
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1800
 __do_softirq+0x23b/0x6b7 kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x195/0x1c0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:538 [inline]
 smp_apic_timer_interrupt+0x11a/0x460 arch/x86/kernel/apic/apic.c:1149
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
 </IRQ>
Modules linked in:
CR2: 0000000000000000
---[ end trace b073d092ad460559 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09d18 EFLAGS: 00010202
RAX: ffffffff8154e38a RBX: 0000000000000101 RCX: ffff8881f39ebf00
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881e05ab1c0
RBP: ffff8881f6e09ec8 R08: ffffffff8154dfce R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffffca20
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881e05ab1c0
FS:  00007f7a43cda6c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001e796d000 CR4: 00000000003406b0
DR0: 0001000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600