==================================================================
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 ffff8881e87c71c8 by task kauditd/23
CPU: 0 PID: 23 Comm: kauditd 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_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
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:native_restore_fl arch/x86/include/asm/irqflags.h:41 [inline]
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/irqflags.h:84 [inline]
RIP: 0010:console_unlock+0x9ea/0xe80 kernel/printk/printk.c:2527
Code: 64 56 86 e8 48 73 e1 02 f6 c3 01 48 8b 5c 24 28 0f 85 61 04 00 00 e8 55 f9 15 00 e8 80 5a 00 00 48 89 5c 24 70 ff 74 24 70 9d d0 f7 ff ff e8 3c f9 15 00 48 c7 05 d1 d7 0c 05 00 00 00 00 e9
RSP: 0018:ffff8881f23ef8e0 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffffffff8149e019 RBX: 0000000000000293 RCX: ffff8881f5e18fc0
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: ffff8881f23efa90 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103e47df0c R11: 1ffff1103e47df0c R12: 0000000000000000
R13: ffffffff85eefb30 R14: ffffffff8267bbc0 R15: dffffc0000000000
vprintk_emit+0x1be/0x380 kernel/printk/printk.c:2032
vprintk_default+0x28/0x30 kernel/printk/printk.c:2059
vprintk_func+0x19a/0x1e0 kernel/printk/printk_safe.c:393
printk+0xcc/0x110 kernel/printk/printk.c:2092
kauditd_printk_skb kernel/audit.c:543 [inline]
kauditd_hold_skb+0x1bc/0x210 kernel/audit.c:578
kauditd_send_queue+0x299/0x2e0 kernel/audit.c:763
kauditd_thread+0x4ff/0x870 kernel/audit.c:887
kthread+0x31e/0x3a0 kernel/kthread.c:288
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
The buggy address belongs to the page:
page:ffffea0007a1f1c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0x8000000000000000()
raw: 8000000000000000 0000000000000000 ffffea0007a1f1c8 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as freed
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x146dc0(GFP_USER|__GFP_NOWARN|__GFP_RETRY_MAYFAIL|__GFP_COMP|__GFP_ZERO)
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_pages include/linux/gfp.h:503 [inline]
__alloc_pages_node include/linux/gfp.h:516 [inline]
alloc_pages_node include/linux/gfp.h:530 [inline]
kmalloc_order mm/slab_common.c:1342 [inline]
kmalloc_order_trace+0x31/0x100 mm/slab_common.c:1358
kmalloc_large include/linux/slab.h:485 [inline]
__kmalloc+0x162/0x2f0 mm/slub.c:3902
__kmalloc_node include/linux/slab.h:422 [inline]
kmalloc_node include/linux/slab.h:599 [inline]
kvmalloc_node+0x88/0xf0 mm/util.c:596
kvmalloc include/linux/mm.h:761 [inline]
kvzalloc include/linux/mm.h:769 [inline]
alloc_netdev_mqs+0x88/0xc50 net/core/dev.c:9629
tun_set_iff+0x535/0xe00 drivers/net/tun.c:2893
__tun_chr_ioctl+0x771/0x18a0 drivers/net/tun.c:3187
tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:3470
do_vfs_ioctl+0x753/0x13f0 fs/ioctl.c:47
ksys_ioctl fs/ioctl.c:742 [inline]
__do_sys_ioctl fs/ioctl.c:749 [inline]
__se_sys_ioctl fs/ioctl.c:747 [inline]
__x64_sys_ioctl+0xe1/0x120 fs/ioctl.c:747
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
kfree+0x1ca/0x260 mm/slub.c:4068
kvfree+0x4c/0x50 mm/util.c:625
netdev_freemem+0x3f/0x60 net/core/dev.c:9583
netdev_release+0x7f/0xb0 net/core/net-sysfs.c:1743
device_release+0x70/0x1a0 drivers/base/core.c:1776
kobject_cleanup lib/kobject.c:716 [inline]
kobject_release lib/kobject.c:747 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x1fe/0x2c0 lib/kobject.c:764
put_device+0x1f/0x30 drivers/base/core.c:3010
free_netdev+0x27e/0x320 net/core/dev.c:9746
tun_set_iff+0x87c/0xe00 drivers/net/tun.c:2924
__tun_chr_ioctl+0x771/0x18a0 drivers/net/tun.c:3187
tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:3470
do_vfs_ioctl+0x753/0x13f0 fs/ioctl.c:47
ksys_ioctl fs/ioctl.c:742 [inline]
__do_sys_ioctl fs/ioctl.c:749 [inline]
__se_sys_ioctl fs/ioctl.c:747 [inline]
__x64_sys_ioctl+0xe1/0x120 fs/ioctl.c:747
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
Memory state around the buggy address:
ffff8881e87c7080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8881e87c7100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881e87c7180: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
^
ffff8881e87c7200: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
ffff8881e87c7280: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================
----------------
Code disassembly (best guess):
0: 64 56 fs push %rsi
2: 86 e8 xchg %ch,%al
4: 48 73 e1 rex.W jae 0xffffffe8
7: 02 f6 add %dh,%dh
9: c3 ret
a: 01 48 8b add %ecx,-0x75(%rax)
d: 5c pop %rsp
e: 24 28 and $0x28,%al
10: 0f 85 61 04 00 00 jne 0x477
16: e8 55 f9 15 00 call 0x15f970
1b: e8 80 5a 00 00 call 0x5aa0
20: 48 89 5c 24 70 mov %rbx,0x70(%rsp)
25: ff 74 24 70 push 0x70(%rsp)
29: 9d popf
* 2a: e9 d0 f7 ff ff jmp 0xfffff7ff <-- trapping instruction
2f: e8 3c f9 15 00 call 0x15f970
34: 48 c7 05 d1 d7 0c 05 movq $0x0,0x50cd7d1(%rip) # 0x50cd810
3b: 00 00 00 00
3f: e9 .byte 0xe9