==================================================================
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 ffff8881caad71c8 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
can_stat_update+0xbab/0xc40 net/can/proc.c:186
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: ffff8881f5e1de80
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
Allocated by task 340:
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
shmem_alloc_inode+0x1a/0x30 mm/shmem.c:3719
alloc_inode fs/inode.c:231 [inline]
new_inode_pseudo+0x62/0x210 fs/inode.c:966
new_inode+0x28/0x1e0 fs/inode.c:995
shmem_get_inode+0x107/0x630 mm/shmem.c:2252
shmem_mknod+0x5c/0x1c0 mm/shmem.c:2844
shmem_mkdir+0x2e/0x60 mm/shmem.c:2895
vfs_mkdir+0x4c7/0x6a0 fs/namei.c:3965
do_mkdirat+0x14c/0x340 fs/namei.c:3987
__do_sys_mkdirat fs/namei.c:3998 [inline]
__se_sys_mkdirat fs/namei.c:3996 [inline]
__x64_sys_mkdirat+0x7b/0x90 fs/namei.c:3996
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Freed by task 633:
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
shmem_free_in_core_inode+0x90/0xb0 mm/shmem.c:3729
i_callback+0x4c/0x70 fs/inode.c:220
__rcu_reclaim kernel/rcu/rcu.h:222 [inline]
rcu_do_batch+0x446/0x980 kernel/rcu/tree.c:2167
rcu_core+0x4bd/0xbd0 kernel/rcu/tree.c:2387
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2396
__do_softirq+0x236/0x660 kernel/softirq.c:292
The buggy address belongs to the object at ffff8881caad7090
which belongs to the cache shmem_inode_cache of size 760
The buggy address is located 312 bytes inside of
760-byte region [ffff8881caad7090, ffff8881caad7388)
The buggy address belongs to the page:
page:ffffea00072ab500 refcount:1 mapcount:0 mapping:ffff8881f5d02780 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5d02780
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+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
shmem_alloc_inode+0x1a/0x30 mm/shmem.c:3719
alloc_inode fs/inode.c:231 [inline]
new_inode_pseudo+0x62/0x210 fs/inode.c:966
new_inode+0x28/0x1e0 fs/inode.c:995
shmem_get_inode+0x107/0x630 mm/shmem.c:2252
shmem_mknod+0x5c/0x1c0 mm/shmem.c:2844
shmem_create+0x2b/0x40 mm/shmem.c:2904
lookup_open fs/namei.c:3379 [inline]
do_last fs/namei.c:3471 [inline]
path_openat+0x1603/0x35c0 fs/namei.c:3683
do_filp_open+0x1ae/0x3f0 fs/namei.c:3713
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
bpf_check+0x8371/0x9cf0 kernel/bpf/verifier.c:9731
bpf_prog_load+0xa5f/0xe10 kernel/bpf/syscall.c:1724
__do_sys_bpf kernel/bpf/syscall.c:2891 [inline]
__se_sys_bpf+0x435/0x570 kernel/bpf/syscall.c:2849
__x64_sys_bpf+0x7b/0x90 kernel/bpf/syscall.c:2849
do_syscall_64+0xcf/0x170 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Memory state around the buggy address:
ffff8881caad7080: fc fc fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881caad7100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881caad7180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881caad7200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881caad7280: 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: 0 PID: 0 Comm: swapper/0 Tainted: G B 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:ffff8881f6e09cf0 EFLAGS: 00010002
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffffffff85c1ad40
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881caad71c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9950
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881caad71c0
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001f33f3000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 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:1488 [inline]
__run_timers+0x84b/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:rcu_idle_exit+0x27b/0x340 kernel/rcu/tree.c:777
Code: 80 3c 3b 00 74 08 4c 89 f7 e8 21 fa 3f 00 48 b8 00 00 00 00 00 00 00 40 49 89 06 48 8b 44 24 10 48 89 44 24 18 ff 74 24 18 9d <48> c7 44 24 20 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 65 48 8b 04
RSP: 0018:ffffffff85c07c20 EFLAGS: 00000a06 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000a06 RBX: 1ffff1103edcb133 RCX: ffffffff814d7f21
RDX: dffffc0000000000 RSI: 0000000000000004 RDI: ffff8881f6e589a0
RBP: ffffffff85c07cd0 R08: dffffc0000000000 R09: ffffed103edcb135
R10: ffffed103edcb135 R11: 1ffff1103edcb134 R12: ffff8881f6e58990
R13: 1ffffffff0b80f88 R14: ffff8881f6e58998 R15: dffffc0000000000
cpuidle_idle_call kernel/sched/idle.c:217 [inline]
do_idle+0x430/0x550 kernel/sched/idle.c:264
cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:356
rest_init+0xe8/0xf0 init/main.c:707
arch_call_rest_init+0xe/0x10 init/main.c:831
start_kernel+0x678/0x73e init/main.c:1036
x86_64_start_reservations+0x2a/0x2c arch/x86/kernel/head64.c:492
x86_64_start_kernel+0x60/0x63 arch/x86/kernel/head64.c:473
secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241
Modules linked in:
CR2: 0000000000000000
---[ end trace e168b6f9e3b7108d ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f6e09cf0 EFLAGS: 00010002
RAX: ffffffff8150a590 RBX: 0000000000000101 RCX: ffffffff85c1ad40
RDX: 0000000000000101 RSI: 0000000000000000 RDI: ffff8881caad71c0
RBP: ffff8881f6e09d30 R08: 0000000000000004 R09: 0000000000000003
R10: ffffed103edc1398 R11: 1ffff1103edc1398 R12: 00000000ffff9950
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881caad71c0
FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001f33f3000 CR4: 00000000003406b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
----------------
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