==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541
Write of size 8 at addr ffff8881dd96f1c8 by task ksoftirqd/1/17
CPU: 1 PID: 17 Comm: ksoftirqd/1 Tainted: G W 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_add_head include/linux/list.h:814 [inline]
enqueue_timer+0x9e/0x2c0 kernel/time/timer.c:541
__internal_add_timer kernel/time/timer.c:554 [inline]
internal_add_timer+0x208/0x3e0 kernel/time/timer.c:604
__mod_timer+0x5ab/0x1150 kernel/time/timer.c:1065
mod_timer+0x1f/0x30 kernel/time/timer.c:1117
br_hello_timer_expired+0x120/0x180 net/bridge/br_stp_timer.c:40
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
Allocated by task 2586:
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
kmem_cache_alloc_node include/linux/slab.h:427 [inline]
__alloc_skb+0x9e/0x500 net/core/skbuff.c:198
alloc_skb include/linux/skbuff.h:1080 [inline]
nlmsg_new include/net/netlink.h:888 [inline]
rtmsg_ifa+0xfa/0x1d0 net/ipv4/devinet.c:1928
__inet_insert_ifa+0x860/0xa60 net/ipv4/devinet.c:567
inet_rtm_newaddr+0xc58/0x1540 net/ipv4/devinet.c:968
rtnetlink_rcv_msg+0xa23/0xbe0 net/core/rtnetlink.c:5290
netlink_rcv_skb+0x1e6/0x430 net/netlink/af_netlink.c:2467
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5308
netlink_unicast_kernel net/netlink/af_netlink.c:1306 [inline]
netlink_unicast+0x88b/0xa40 net/netlink/af_netlink.c:1332
netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:638 [inline]
__sock_sendmsg net/socket.c:650 [inline]
__sys_sendto+0x414/0x570 net/socket.c:1961
__do_sys_sendto net/socket.c:1973 [inline]
__se_sys_sendto net/socket.c:1969 [inline]
__x64_sys_sendto+0xe5/0x100 net/socket.c:1969
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Freed by task 2586:
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
kfree_skbmem+0x10c/0x180 net/core/skbuff.c:654
__kfree_skb net/core/skbuff.c:690 [inline]
consume_skb+0xb5/0x240 net/core/skbuff.c:849
netlink_broadcast_filtered+0x1198/0x1290 net/netlink/af_netlink.c:1516
netlink_broadcast net/netlink/af_netlink.c:1538 [inline]
nlmsg_multicast include/net/netlink.h:968 [inline]
nlmsg_notify+0xed/0x1b0 net/netlink/af_netlink.c:2510
rtnl_notify+0x9a/0xc0 net/core/rtnetlink.c:737
rtmsg_ifa+0x143/0x1d0 net/ipv4/devinet.c:1939
__inet_insert_ifa+0x860/0xa60 net/ipv4/devinet.c:567
inet_rtm_newaddr+0xc58/0x1540 net/ipv4/devinet.c:968
rtnetlink_rcv_msg+0xa23/0xbe0 net/core/rtnetlink.c:5290
netlink_rcv_skb+0x1e6/0x430 net/netlink/af_netlink.c:2467
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5308
netlink_unicast_kernel net/netlink/af_netlink.c:1306 [inline]
netlink_unicast+0x88b/0xa40 net/netlink/af_netlink.c:1332
netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:638 [inline]
__sock_sendmsg net/socket.c:650 [inline]
__sys_sendto+0x414/0x570 net/socket.c:1961
__do_sys_sendto net/socket.c:1973 [inline]
__se_sys_sendto net/socket.c:1969 [inline]
__x64_sys_sendto+0xe5/0x100 net/socket.c:1969
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 ffff8881dd96f140
which belongs to the cache skbuff_head_cache of size 240
The buggy address is located 136 bytes inside of
240-byte region [ffff8881dd96f140, ffff8881dd96f230)
The buggy address belongs to the page:
page:ffffea0007765bc0 refcount:1 mapcount:0 mapping:ffff8881f1ccd400 index:0x0
flags: 0x8000000000000200(slab)
raw: 8000000000000200 dead000000000100 dead000000000122 ffff8881f1ccd400
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY)
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
kmem_cache_alloc_node include/linux/slab.h:427 [inline]
__alloc_skb+0x9e/0x500 net/core/skbuff.c:198
alloc_skb include/linux/skbuff.h:1080 [inline]
nlmsg_new include/net/netlink.h:888 [inline]
netlink_ack+0x2e2/0xa70 net/netlink/af_netlink.c:2401
netlink_rcv_skb+0x26b/0x430 net/netlink/af_netlink.c:2473
rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:5308
netlink_unicast_kernel net/netlink/af_netlink.c:1306 [inline]
netlink_unicast+0x88b/0xa40 net/netlink/af_netlink.c:1332
netlink_sendmsg+0x88d/0xb30 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:638 [inline]
__sock_sendmsg net/socket.c:650 [inline]
__sys_sendto+0x414/0x570 net/socket.c:1961
__do_sys_sendto net/socket.c:1973 [inline]
__se_sys_sendto net/socket.c:1969 [inline]
__x64_sys_sendto+0xe5/0x100 net/socket.c:1969
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+0x2a9/0x3a0 mm/page_alloc.c:3085
free_unref_page_list+0x110/0x4c0 mm/page_alloc.c:3154
release_pages+0xa62/0xaa0 mm/swap.c:842
free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:297
tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:189 [inline]
tlb_flush_mmu mm/mmu_gather.c:196 [inline]
tlb_finish_mmu+0x175/0x300 mm/mmu_gather.c:277
exit_mmap+0x2db/0x520 mm/mmap.c:3193
__mmput+0x92/0x2e0 kernel/fork.c:1101
mmput+0x47/0x60 kernel/fork.c:1122
exit_mm kernel/exit.c:538 [inline]
do_exit+0x99f/0x2660 kernel/exit.c:848
do_group_exit+0x13e/0x300 kernel/exit.c:984
get_signal+0xdee/0x13d0 kernel/signal.c:2738
do_signal+0xad/0xda0 arch/x86/kernel/signal.c:809
exit_to_usermode_loop+0xc4/0x1b0 arch/x86/entry/common.c:159
prepare_exit_to_usermode+0x18e/0x1f0 arch/x86/entry/common.c:194
syscall_return_slowpath+0x61/0x80 arch/x86/entry/common.c:274
ret_from_fork+0x15/0x30 arch/x86/entry/entry_64.S:346
Memory state around the buggy address:
ffff8881dd96f080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc
ffff8881dd96f100: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8881dd96f180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881dd96f200: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc
ffff8881dd96f280: 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: 0 Comm: swapper/1 Tainted: G B W 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: 0018:ffff8881f6f09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f5dc3f00
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881dd96f1c0
RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffae60
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881dd96f1c0
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000005c0e000 CR4: 00000000003406a0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
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
invoke_softirq kernel/softirq.c:373 [inline]
irq_exit+0x197/0x1c0 kernel/softirq.c:413
exiting_irq arch/x86/include/asm/apic.h:539 [inline]
smp_apic_timer_interrupt+0x11d/0x490 arch/x86/kernel/apic/apic.c:1161
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:834
RIP: 0010:default_idle+0x23/0x40 arch/x86/kernel/process.c:578
Code: 90 90 00 00 90 90 00 55 48 89 e5 e8 87 b2 f5 fd bf 01 00 00 00 89 c6 e8 bb 1c fc fc 0f 1f 44 00 00 0f 00 2d cf c2 59 00 fb f4 68 b2 f5 fd bf ff ff ff ff 89 c6 e8 9c 1c fc fc 5d c3 66 2e 0f
RSP: 0018:ffff8881f5df7d80 EFLAGS: 000002c6 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000001 RBX: ffff8881f5dc3f00 RCX: ffff8881f5dc3f00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff8881f5df7d80 R08: dffffc0000000000 R09: ffffed103ebb87e1
R10: ffffed103ebb87e1 R11: 1ffff1103ebb87e0 R12: 0000000000000001
R13: 1ffff1103ebb87e0 R14: 0000000000000000 R15: ffffffff862bb528
arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:568
default_idle_call kernel/sched/idle.c:94 [inline]
cpuidle_idle_call kernel/sched/idle.c:154 [inline]
do_idle+0x21d/0x550 kernel/sched/idle.c:264
cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:356
start_secondary+0x366/0x420 arch/x86/kernel/smpboot.c:277
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241
Modules linked in:
CR2: 0000000000000000
---[ end trace 88cf981c5f123919 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6f09cf0 EFLAGS: 00010202
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffff8881f5dc3f00
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881dd96f1c0
RBP: ffff8881f6f09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103ede1398 R11: 1ffff1103ede1398 R12: 00000000ffffae60
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881dd96f1c0
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 0000000005c0e000 CR4: 00000000003406a0
DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess):
0: 90 nop
1: 90 nop
2: 00 00 add %al,(%rax)
4: 90 nop
5: 90 nop
6: 00 55 48 add %dl,0x48(%rbp)
9: 89 e5 mov %esp,%ebp
b: e8 87 b2 f5 fd call 0xfdf5b297
10: bf 01 00 00 00 mov $0x1,%edi
15: 89 c6 mov %eax,%esi
17: e8 bb 1c fc fc call 0xfcfc1cd7
1c: 0f 1f 44 00 00 nopl 0x0(%rax,%rax,1)
21: 0f 00 2d cf c2 59 00 verw 0x59c2cf(%rip) # 0x59c2f7
28: fb sti
29: f4 hlt
* 2a: e8 68 b2 f5 fd call 0xfdf5b297 <-- trapping instruction
2f: bf ff ff ff ff mov $0xffffffff,%edi
34: 89 c6 mov %eax,%esi
36: e8 9c 1c fc fc call 0xfcfc1cd7
3b: 5d pop %rbp
3c: c3 ret
3d: 66 data16
3e: 2e cs
3f: 0f .byte 0xf