==================================================================
BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:814 [inline]
BUG: KASAN: use-after-free in enqueue_timer+0xb7/0x300 kernel/time/timer.c:541
Write of size 8 at addr ffff8881ea8771c8 by task kauditd/23
CPU: 1 PID: 23 Comm: kauditd Not tainted 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__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_add_head include/linux/list.h:814 [inline]
enqueue_timer+0xb7/0x300 kernel/time/timer.c:541
__internal_add_timer kernel/time/timer.c:554 [inline]
internal_add_timer+0x240/0x430 kernel/time/timer.c:604
__mod_timer+0x6f1/0x13e0 kernel/time/timer.c:1065
call_timer_fn+0x36/0x390 kernel/time/timer.c:1448
expire_timers kernel/time/timer.c:1493 [inline]
__run_timers+0x879/0xbe0 kernel/time/timer.c:1817
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
__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:539 [inline]
smp_apic_timer_interrupt+0x11a/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+0xa62/0xfa0 kernel/printk/printk.c:2527
Code: 03 84 db 4c 8d ac 24 00 01 00 00 0f 85 13 05 00 00 e8 52 e3 16 00 e8 5d 5f 00 00 48 8b 44 24 20 48 89 44 24 70 ff 74 24 70 9d 99 f7 ff ff e8 34 e3 16 00 48 c7 05 e9 15 a0 05 00 00 00 00 e9
RSP: 0018:ffff8881f23ef940 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000246 RBX: 0000000000000000 RCX: ffff8881f5e15e80
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000001
RBP: ffff8881f23efaf0 R08: dffffc0000000000 R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: dffffc0000000000
R13: ffff8881f23efa40 R14: 0000000000000000 R15: ffffffff812ee850
vprintk_emit+0x1e0/0x3f0 kernel/printk/printk.c:2032
printk+0xd1/0x111 kernel/printk/printk.c:2092
kauditd_printk_skb kernel/audit.c:543 [inline]
kauditd_hold_skb+0x1b3/0x200 kernel/audit.c:578
kauditd_send_queue+0x297/0x2f0 kernel/audit.c:763
kauditd_thread+0x4ff/0x860 kernel/audit.c:887
kthread+0x2da/0x360 kernel/kthread.c:288
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Allocated by task 164:
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]
kmem_cache_alloc+0xd9/0x250 mm/slub.c:2842
getname_flags+0xb8/0x4e0 fs/namei.c:141
user_path_at_empty+0x28/0x50 fs/namei.c:2703
do_readlinkat+0x114/0x3a0 fs/stat.c:398
__do_sys_readlink fs/stat.c:431 [inline]
__se_sys_readlink fs/stat.c:428 [inline]
__x64_sys_readlink+0x7b/0x90 fs/stat.c:428
do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Freed by task 164:
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]
kmem_cache_free+0x10b/0x2c0 mm/slub.c:3096
putname fs/namei.c:262 [inline]
filename_lookup+0x50e/0x6e0 fs/namei.c:2432
do_readlinkat+0x114/0x3a0 fs/stat.c:398
__do_sys_readlink fs/stat.c:431 [inline]
__se_sys_readlink fs/stat.c:428 [inline]
__x64_sys_readlink+0x7b/0x90 fs/stat.c:428
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 ffff8881ea876600
which belongs to the cache names_cache of size 4096
The buggy address is located 3016 bytes inside of
4096-byte region [ffff8881ea876600, ffff8881ea877600)
The buggy address belongs to the page:
page:ffffea0007aa1c00 refcount:1 mapcount:0 mapping:ffff8881f5cfc500 index:0x0 compound_mapcount: 0
flags: 0x8000000000010200(slab|head)
raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cfc500
raw: 0000000000000000 0000000000070007 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:4893
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]
kmem_cache_alloc+0x109/0x250 mm/slub.c:2842
getname_flags+0xb8/0x4e0 fs/namei.c:141
user_path_at_empty+0x28/0x50 fs/namei.c:2703
user_path_at include/linux/namei.h:49 [inline]
vfs_statx+0x115/0x210 fs/stat.c:187
vfs_fstatat include/linux/fs.h:3387 [inline]
__do_sys_newfstatat fs/stat.c:367 [inline]
__se_sys_newfstatat+0xce/0x770 fs/stat.c:361
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:4953 [inline]
__free_pages+0xaf/0x140 mm/page_alloc.c:4961
__vunmap+0x75b/0x890 mm/vmalloc.c:2260
kcov_mmap+0x8c/0x120 kernel/kcov.c:474
call_mmap include/linux/fs.h:1996 [inline]
mmap_region+0x110d/0x16f0 mm/mmap.c:1812
do_mmap+0x822/0xd30 mm/mmap.c:1581
do_mmap_pgoff include/linux/mm.h:2480 [inline]
vm_mmap_pgoff+0x1b5/0x260 mm/util.c:528
ksys_mmap_pgoff+0x168/0x1e0 mm/mmap.c:1631
do_syscall_64+0xca/0x1c0 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x5c/0xc1
Memory state around the buggy address:
ffff8881ea877080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881ea877100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881ea877180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8881ea877200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8881ea877280: 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: 17 Comm: ksoftirqd/1 Tainted: G B 5.4.290-syzkaller-00017-g6b07fcd94a6a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f5e27b58 EFLAGS: 00010206
RAX: ffffffff8154e8ca RBX: 0000000000000100 RCX: ffff8881f5e10000
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881ea8771c0
RBP: ffff8881f5e27d08 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffff97b8
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881ea8771c0
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001f41dd000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
call_timer_fn+0x36/0x390 kernel/time/timer.c:1448
expire_timers kernel/time/timer.c:1493 [inline]
__run_timers+0x879/0xbe0 kernel/time/timer.c:1817
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1830
__do_softirq+0x23b/0x6b7 kernel/softirq.c:292
run_ksoftirqd+0x1f/0x30 kernel/softirq.c:603
smpboot_thread_fn+0x545/0x930 kernel/smpboot.c:165
kthread+0x2da/0x360 kernel/kthread.c:288
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:354
Modules linked in:
CR2: 0000000000000000
---[ end trace 3e9558deda9b0ab1 ]---
RIP: 0010:0x0
Code: Bad RIP value.
RSP: 0018:ffff8881f5e27b58 EFLAGS: 00010206
RAX: ffffffff8154e8ca RBX: 0000000000000100 RCX: ffff8881f5e10000
RDX: 0000000080000100 RSI: 0000000000000000 RDI: ffff8881ea8771c0
RBP: ffff8881f5e27d08 R08: ffffffff8154e50e R09: 0000000000000003
R10: ffffffffffffffff R11: dffffc0000000001 R12: 00000000ffff97b8
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8881ea8771c0
FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffd6 CR3: 00000001f41dd000 CR4: 00000000003406a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 03 84 db 4c 8d ac 24 add 0x24ac8d4c(%rbx,%rbx,8),%eax
7: 00 01 add %al,(%rcx)
9: 00 00 add %al,(%rax)
b: 0f 85 13 05 00 00 jne 0x524
11: e8 52 e3 16 00 call 0x16e368
16: e8 5d 5f 00 00 call 0x5f78
1b: 48 8b 44 24 20 mov 0x20(%rsp),%rax
20: 48 89 44 24 70 mov %rax,0x70(%rsp)
25: ff 74 24 70 push 0x70(%rsp)
29: 9d popf
* 2a: e9 99 f7 ff ff jmp 0xfffff7c8 <-- trapping instruction
2f: e8 34 e3 16 00 call 0x16e368
34: 48 c7 05 e9 15 a0 05 movq $0x0,0x5a015e9(%rip) # 0x5a01628
3b: 00 00 00 00
3f: e9 .byte 0xe9