==================================================================
BUG: KASAN: slab-out-of-bounds in hlist_move_list include/linux/list.h:986 [inline]
BUG: KASAN: slab-out-of-bounds in collect_expired_timers kernel/time/timer.c:1517 [inline]
BUG: KASAN: slab-out-of-bounds in __run_timers+0x28c/0x6c4 kernel/time/timer.c:1753
Write of size 8 at addr ffff0000ca2cda40 by task swapper/1/0

CPU: 1 PID: 0 Comm: swapper/1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
Call trace:
 dump_backtrace+0x0/0x43c arch/arm64/kernel/stacktrace.c:152
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:216
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf8/0x160 lib/dump_stack.c:106
 print_address_description+0x78/0x30c mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xec/0x15c mm/kasan/report.c:451
 __asan_report_store8_noabort+0x44/0x50 mm/kasan/report_generic.c:314
 hlist_move_list include/linux/list.h:986 [inline]
 collect_expired_timers kernel/time/timer.c:1517 [inline]
 __run_timers+0x28c/0x6c4 kernel/time/timer.c:1753
 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1780
 handle_softirqs+0x344/0xbf0 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
 invoke_softirq kernel/softirq.c:457 [inline]
 __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659
 irq_exit+0x14/0x88 kernel/softirq.c:683
 handle_domain_irq+0x14c/0x1fc kernel/irq/irqdesc.c:711
 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765
 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:903
 do_interrupt_handler+0x6c/0x88 arch/arm64/kernel/entry-common.c:267
 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470
 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522
 arch_local_irq_enable+0xc/0x18 arch/arm64/include/asm/irqflags.h:35
 default_idle_call+0xcc/0x418 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x1c8/0x480 kernel/sched/idle.c:306
 cpu_startup_entry+0x24/0x28 kernel/sched/idle.c:403
 secondary_start_kernel+0x23c/0x294 arch/arm64/kernel/smp.c:265
 __secondary_switched+0x94/0x98 arch/arm64/kernel/head.S:661

Allocated by task 27632:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb0/0xf0 mm/kasan/common.c:522
 kasan_kmalloc include/linux/kasan.h:264 [inline]
 __kmalloc_node_track_caller+0x234/0x3bc mm/slub.c:4968
 kmalloc_reserve+0xe4/0x26c net/core/skbuff.c:356
 __alloc_skb+0x23c/0x67c net/core/skbuff.c:427
 alloc_skb include/linux/skbuff.h:1162 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1182 [inline]
 netlink_sendmsg+0x548/0x9cc net/netlink/af_netlink.c:1893
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x61c/0x920 net/socket.c:2436
 ___sys_sendmsg+0x1d0/0x240 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg net/socket.c:2526 [inline]
 __arm64_sys_sendmsg+0x1a8/0x254 net/socket.c:2526
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

Freed by task 27632:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4c/0x84 mm/kasan/common.c:46
 kasan_set_free_info+0x28/0x4c mm/kasan/generic.c:360
 ____kasan_slab_free+0x118/0x164 mm/kasan/common.c:366
 __kasan_slab_free+0x18/0x28 mm/kasan/common.c:374
 kasan_slab_free include/linux/kasan.h:230 [inline]
 slab_free_hook mm/slub.c:1710 [inline]
 slab_free_freelist_hook+0x128/0x1e8 mm/slub.c:1736
 slab_free mm/slub.c:3504 [inline]
 kfree+0x170/0x40c mm/slub.c:4564
 skb_free_head net/core/skbuff.c:655 [inline]
 skb_release_data+0x3c0/0x5ac net/core/skbuff.c:677
 skb_release_all net/core/skbuff.c:742 [inline]
 __kfree_skb net/core/skbuff.c:756 [inline]
 consume_skb+0x138/0x33c net/core/skbuff.c:914
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0x62c/0x8b0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x6e8/0x9cc net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x61c/0x920 net/socket.c:2436
 ___sys_sendmsg+0x1d0/0x240 net/socket.c:2490
 __sys_sendmsg net/socket.c:2519 [inline]
 __do_sys_sendmsg net/socket.c:2528 [inline]
 __se_sys_sendmsg net/socket.c:2526 [inline]
 __arm64_sys_sendmsg+0x1a8/0x254 net/socket.c:2526
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:142
 do_el0_svc+0x58/0x14c arch/arm64/kernel/syscall.c:181
 el0_svc+0x78/0x1e0 arch/arm64/kernel/entry-common.c:608
 el0t_64_sync_handler+0xcc/0xe4 arch/arm64/kernel/entry-common.c:626
 el0t_64_sync+0x1a0/0x1a4 arch/arm64/kernel/entry.S:584

The buggy address belongs to the object at ffff0000ca2cd800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 64 bytes to the right of
 512-byte region [ffff0000ca2cd800, ffff0000ca2cda00)
The buggy address belongs to the page:
page:0000000053904531 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff0000ca2cc800 pfn:0x10a2cc
head:0000000053904531 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x5ffc00000010200(slab|head|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000010200 fffffc00036ca208 fffffc0003acfd08 ffff0000c0002600
raw: ffff0000ca2cc800 000000000010000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000ca2cd900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff0000ca2cd980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff0000ca2cda00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                                           ^
 ffff0000ca2cda80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff0000ca2cdb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
Mem abort info:
  ESR = 0x0000000086000004
  EC = 0x21: IABT (current EL), IL = 32 bits
  SET = 0, FnV = 0
  EA = 0, S1PTW = 0
  FSC = 0x04: level 0 translation fault
user pgtable: 4k pages, 48-bit VAs, pgdp=0000000102639000
[0000000000000000] pgd=0000000000000000, p4d=0000000000000000
Internal error: Oops: 0000000086000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G    B             syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/30/2025
pstate: 42400805 (nZcv daif +PAN -UAO +TCO -DIT -SSBS BTYPE=-c)
pc : 0x0
lr : call_timer_fn+0x19c/0x858 kernel/time/timer.c:1451
sp : ffff800008017b40
x29: ffff800008017c00 x28: 1fffe0001814d001 x27: dfff800000000000
x26: ffff700001002f6c x25: ffff80001417d310 x24: 0000000000000002
x23: ffff0000ca2cda38 x22: ffff800008017b80 x21: 0000000000000101
x20: ffff0000c0a68008 x19: 0000000000000000 x18: 0000000000000104
x17: 0000000000000000 x16: ffff8000111cbe1c x15: 00000000ffffffff
x14: 0000000000ff0100 x13: 0000000000000000 x12: 0000000000ff0100
x11: 0000000000000101 x10: 0000000000000000 x9 : ffff80000837faac
x8 : ffff0000c0a68000 x7 : 0000000000000000 x6 : ffff80000837f9f0
x5 : 0000000000000000 x4 : 0000000000000001 x3 : 0000000000000000
x2 : 0000000000000000 x1 : ffff8000117d8f20 x0 : ffff0000ca2cda38
Call trace:
 0x0
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x46c/0x6c4 kernel/time/timer.c:1767
 run_timer_softirq+0x7c/0x114 kernel/time/timer.c:1780
 handle_softirqs+0x344/0xbf0 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 do_softirq_own_stack include/asm-generic/softirq_stack.h:10 [inline]
 invoke_softirq kernel/softirq.c:457 [inline]
 __irq_exit_rcu+0x240/0x440 kernel/softirq.c:659
 irq_exit+0x14/0x88 kernel/softirq.c:683
 handle_domain_irq+0x14c/0x1fc kernel/irq/irqdesc.c:711
 gic_handle_irq+0x78/0x1c8 drivers/irqchip/irq-gic-v3.c:765
 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:903
 do_interrupt_handler+0x6c/0x88 arch/arm64/kernel/entry-common.c:267
 el1_interrupt+0x30/0x58 arch/arm64/kernel/entry-common.c:454
 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:470
 el1h_64_irq+0x78/0x7c arch/arm64/kernel/entry.S:522
 arch_local_irq_enable+0xc/0x18 arch/arm64/include/asm/irqflags.h:35
 default_idle_call+0xcc/0x418 kernel/sched/idle.c:112
 cpuidle_idle_call kernel/sched/idle.c:194 [inline]
 do_idle+0x1c8/0x480 kernel/sched/idle.c:306
 cpu_startup_entry+0x24/0x28 kernel/sched/idle.c:403
 secondary_start_kernel+0x23c/0x294 arch/arm64/kernel/smp.c:265
 __secondary_switched+0x94/0x98 arch/arm64/kernel/head.S:661