==================================================================
BUG: KASAN: slab-use-after-free in __hlist_del include/linux/list.h:982 [inline]
BUG: KASAN: slab-use-after-free in hlist_del_rcu include/linux/rculist.h:560 [inline]
BUG: KASAN: slab-use-after-free in __xfrm_state_delete+0x9e5/0xa30 net/xfrm/xfrm_state.c:830
Write of size 8 at addr ffff8880780348b0 by task syz.3.209/6785
CPU: 1 UID: 0 PID: 6785 Comm: syz.3.209 Tainted: G U syzkaller #0 PREEMPT(full)
Tainted: [U]=USER
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xcd/0x630 mm/kasan/report.c:482
kasan_report+0xe0/0x110 mm/kasan/report.c:595
__hlist_del include/linux/list.h:982 [inline]
hlist_del_rcu include/linux/rculist.h:560 [inline]
__xfrm_state_delete+0x9e5/0xa30 net/xfrm/xfrm_state.c:830
xfrm_timer_handler+0x86c/0xf10 net/xfrm/xfrm_state.c:716
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1825
hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842
handle_softirqs+0x216/0x8e0 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:__timer_delete_sync+0x7c/0x1b0 kernel/time/timer.c:1610
Code: fb ef ff 48 89 de 4c 89 ef e8 00 f5 ef ff 9c 5b 81 e3 00 02 00 00 31 ff 48 89 de e8 4e 9e 13 00 58 48 85 db 0f 85 09 01 00 00 cf a2 13 00 31 ff 65 8b 1d 16 f9 2e 12 81 e3 00 00 0f 00 89 de
RSP: 0018:ffffc90003547ad8 EFLAGS: 00000283
RAX: 0000000000042e01 RBX: 0000000000000000 RCX: ffffc9000ca7c000
RDX: 0000000000080000 RSI: ffffffff81a7680f RDI: 0000000000000007
RBP: ffffc90003547b20 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffffc90003547b48 R14: 1ffffffff1c42240 R15: ffff88806de82e00
schedule_timeout+0x12b/0x290 kernel/time/sleep_timeout.c:100
snd_rawmidi_write+0x496/0xc10 sound/core/rawmidi.c:1616
vfs_write+0x2a0/0x11d0 fs/read_write.c:684
ksys_write+0x1f8/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7efdc3b8eba9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007efdc4992038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007efdc3dd6090 RCX: 00007efdc3b8eba9
RDX: 000000100000a3d9 RSI: 0000200000000400 RDI: 0000000000000005
RBP: 00007efdc3c11e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efdc3dd6128 R14: 00007efdc3dd6090 R15: 00007ffc1041f458
Allocated by task 6333:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:356
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4191 [inline]
slab_alloc_node mm/slub.c:4240 [inline]
kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4247
xfrm_state_alloc+0x23/0x5c0 net/xfrm/xfrm_state.c:733
__find_acq_core+0xb59/0x2900 net/xfrm/xfrm_state.c:1833
xfrm_find_acq+0x7b/0xa0 net/xfrm/xfrm_state.c:2353
xfrm_alloc_userspi+0x58e/0xbb0 net/xfrm/xfrm_user.c:1863
xfrm_user_rcv_msg+0x4fe/0xb60 net/xfrm/xfrm_user.c:3501
netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3523
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg net/socket.c:729 [inline]
____sys_sendmsg+0xa98/0xc70 net/socket.c:2614
___sys_sendmsg+0x134/0x1d0 net/socket.c:2668
__sys_sendmsg+0x16d/0x220 net/socket.c:2700
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 9:
kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
kasan_save_track+0x14/0x30 mm/kasan/common.c:68
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:243 [inline]
__kasan_slab_free+0x60/0x70 mm/kasan/common.c:275
kasan_slab_free include/linux/kasan.h:233 [inline]
slab_free_hook mm/slub.c:2422 [inline]
slab_free mm/slub.c:4695 [inline]
kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4797
xfrm_state_free net/xfrm/xfrm_state.c:591 [inline]
xfrm_state_gc_destroy net/xfrm/xfrm_state.c:618 [inline]
xfrm_state_gc_task+0x50a/0x770 net/xfrm/xfrm_state.c:634
process_one_work+0x9cf/0x1b70 kernel/workqueue.c:3236
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
The buggy address belongs to the object at ffff888078034880
which belongs to the cache xfrm_state of size 928
The buggy address is located 48 bytes inside of
freed 928-byte region [ffff888078034880, ffff888078034c20)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x78034
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801c752140 dead000000000122 0000000000000000
raw: 0000000000000000 00000000800f000f 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801c752140 dead000000000122 0000000000000000
head: 0000000000000000 00000000800f000f 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0001e00d01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6329, tgid 6328 (syz.1.77), ts 140193424939, free_ts 115720364339
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851
prep_new_page mm/page_alloc.c:1859 [inline]
get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858
__alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:2492 [inline]
allocate_slab mm/slub.c:2660 [inline]
new_slab+0x247/0x330 mm/slub.c:2714
___slab_alloc+0xcf2/0x1750 mm/slub.c:3901
__slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992
__slab_alloc_node mm/slub.c:4067 [inline]
slab_alloc_node mm/slub.c:4228 [inline]
kmem_cache_alloc_noprof+0xef/0x3b0 mm/slub.c:4247
xfrm_state_alloc+0x23/0x5c0 net/xfrm/xfrm_state.c:733
__find_acq_core+0xb59/0x2900 net/xfrm/xfrm_state.c:1833
xfrm_find_acq+0x7b/0xa0 net/xfrm/xfrm_state.c:2353
xfrm_alloc_userspi+0x58e/0xbb0 net/xfrm/xfrm_user.c:1863
xfrm_user_rcv_msg+0x4fe/0xb60 net/xfrm/xfrm_user.c:3501
netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552
xfrm_netlink_rcv+0x71/0x90 net/xfrm/xfrm_user.c:3523
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x5a7/0x870 net/netlink/af_netlink.c:1346
page last free pid 23 tgid 23 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
rcu_do_batch kernel/rcu/tree.c:2605 [inline]
rcu_core+0x799/0x1530 kernel/rcu/tree.c:2861
handle_softirqs+0x216/0x8e0 kernel/softirq.c:579
run_ksoftirqd kernel/softirq.c:968 [inline]
run_ksoftirqd+0x3a/0x60 kernel/softirq.c:960
smpboot_thread_fn+0x3f7/0xae0 kernel/smpboot.c:160
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x56d/0x730 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
Memory state around the buggy address:
ffff888078034780: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
ffff888078034800: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888078034880: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff888078034900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888078034980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: fb sti
1: ef out %eax,(%dx)
2: ff 48 89 decl -0x77(%rax)
5: de 4c 89 ef fimuls -0x11(%rcx,%rcx,4)
9: e8 00 f5 ef ff call 0xffeff50e
e: 9c pushf
f: 5b pop %rbx
10: 81 e3 00 02 00 00 and $0x200,%ebx
16: 31 ff xor %edi,%edi
18: 48 89 de mov %rbx,%rsi
1b: e8 4e 9e 13 00 call 0x139e6e
20: 58 pop %rax
21: 48 85 db test %rbx,%rbx
24: 0f 85 09 01 00 00 jne 0x133
* 2a: e8 cf a2 13 00 call 0x13a2fe <-- trapping instruction
2f: 31 ff xor %edi,%edi
31: 65 8b 1d 16 f9 2e 12 mov %gs:0x122ef916(%rip),%ebx # 0x122ef94e
38: 81 e3 00 00 0f 00 and $0xf0000,%ebx
3e: 89 de mov %ebx,%esi