==================================================================
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+0x696/0xca0 net/xfrm/xfrm_state.c:830
Write of size 8 at addr ffff8880545b9df0 by task syz.4.219/6800
CPU: 1 UID: 0 PID: 6800 Comm: syz.4.219 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_address_description mm/kasan/report.c:378 [inline]
print_report+0xca/0x240 mm/kasan/report.c:482
kasan_report+0x118/0x150 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+0x696/0xca0 net/xfrm/xfrm_state.c:830
xfrm_state_delete net/xfrm/xfrm_state.c:856 [inline]
xfrm_state_delete_tunnel net/xfrm/xfrm_state.c:3091 [inline]
__xfrm_state_delete+0x87b/0xca0 net/xfrm/xfrm_state.c:837
xfrm_timer_handler+0x18f/0xa00 net/xfrm/xfrm_state.c:716
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825
hrtimer_run_softirq+0x187/0x2b0 kernel/time/hrtimer.c:1842
handle_softirqs+0x283/0x870 kernel/softirq.c:579
__do_softirq kernel/softirq.c:613 [inline]
invoke_softirq kernel/softirq.c:453 [inline]
__irq_exit_rcu+0xca/0x1f0 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+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:202
Code: 90 f3 0f 1e fa 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 1a 9f 20 f6 48 89 df e8 72 36 21 f6 e8 0d 89 4a f6 fb bf 01 00 00 00 42 2e 13 f6 65 8b 05 cb d0 23 07 85 c0 74 07 5b c3 cc cc cc cc
RSP: 0018:ffffc9003b1e6730 EFLAGS: 00000286
RAX: f34402c7c84dae00 RBX: ffff88807cbf3e70 RCX: f34402c7c84dae00
RDX: 0000000000000006 RSI: ffffffff8d9b9b30 RDI: 0000000000000001
RBP: ffffc9003b1e6870 R08: ffffffff8fa3a537 R09: 1ffffffff1f474a6
R10: dffffc0000000000 R11: fffffbfff1f474a7 R12: ffffc9003b1e67c0
R13: 00000003fffffffc R14: 0000000000000000 R15: ffff88805634d8c0
spin_unlock_irq include/linux/spinlock.h:401 [inline]
shmem_add_to_page_cache+0x8ee/0xba0 mm/shmem.c:948
shmem_alloc_and_add_folio+0x846/0xf60 mm/shmem.c:1973
shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2597
shmem_get_folio mm/shmem.c:2703 [inline]
shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3353
generic_perform_write+0x2c5/0x900 mm/filemap.c:4175
shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3528
__kernel_write_iter+0x425/0x910 fs/read_write.c:619
dump_emit_page fs/coredump.c:1296 [inline]
dump_user_range+0x8a0/0xc90 fs/coredump.c:1370
elf_core_dump+0x337b/0x3990 fs/binfmt_elf.c:2085
coredump_write+0x1166/0x1900 fs/coredump.c:1049
vfs_coredump+0x1daa/0x2a50 fs/coredump.c:1168
get_signal+0x1109/0x1340 kernel/signal.c:3019
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73
exc_page_fault+0x9f/0xf0 arch/x86/mm/fault.c:1535
asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x2dbd631a5b1b
Code: Unable to access opcode bytes at 0x2dbd631a5af1.
RSP: 002b:0000200000000148 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f52923d5fa0 RCX: 00007f529218eba9
RDX: 0000200000000180 RSI: 0000200000000140 RDI: 0000000008000000
RBP: 00007f5292211e19 R08: 0000200000000200 R09: 0000200000000200
R10: 00002000000001c0 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f52923d6038 R14: 00007f52923d5fa0 R15: 00007ffc2bfa59a8
Allocated by task 6211:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:330 [inline]
__kasan_slab_alloc+0x6c/0x80 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+0x1c1/0x3c0 mm/slub.c:4247
xfrm_state_alloc+0x24/0x2f0 net/xfrm/xfrm_state.c:733
__find_acq_core+0x8a7/0x1c00 net/xfrm/xfrm_state.c:1833
xfrm_find_acq+0x78/0xa0 net/xfrm/xfrm_state.c:2353
xfrm_alloc_userspi+0x6b3/0xc90 net/xfrm/xfrm_user.c:1863
xfrm_user_rcv_msg+0x7a3/0xab0 net/xfrm/xfrm_user.c:3501
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:729
____sys_sendmsg+0x505/0x830 net/socket.c:2614
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
__sys_sendmsg net/socket.c:2700 [inline]
__do_sys_sendmsg net/socket.c:2705 [inline]
__se_sys_sendmsg net/socket.c:2703 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 9:
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576
poison_slab_object mm/kasan/common.c:243 [inline]
__kasan_slab_free+0x5b/0x80 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+0x18f/0x400 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+0x52d/0x6b0 net/xfrm/xfrm_state.c:634
process_one_work kernel/workqueue.c:3236 [inline]
process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319
worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
kthread+0x70e/0x8a0 kernel/kthread.c:463
ret_from_fork+0x436/0x7d0 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 ffff8880545b9dc0
which belongs to the cache xfrm_state of size 928
The buggy address is located 48 bytes inside of
freed 928-byte region [ffff8880545b9dc0, ffff8880545ba160)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880545b8440 pfn:0x545b8
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff88801b39b280 0000000000000000 0000000000000001
raw: ffff8880545b8440 00000000000f000c 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b39b280 0000000000000000 0000000000000001
head: ffff8880545b8440 00000000000f000c 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0001516e01 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 6040, tgid 6038 (syz.4.17), ts 101847591130, free_ts 101842314659
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
prep_new_page mm/page_alloc.c:1859 [inline]
get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858
__alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
alloc_slab_page mm/slub.c:2492 [inline]
allocate_slab+0x8a/0x370 mm/slub.c:2660
new_slab mm/slub.c:2714 [inline]
___slab_alloc+0xbeb/0x1420 mm/slub.c:3901
__slab_alloc mm/slub.c:3992 [inline]
__slab_alloc_node mm/slub.c:4067 [inline]
slab_alloc_node mm/slub.c:4228 [inline]
kmem_cache_alloc_noprof+0x283/0x3c0 mm/slub.c:4247
xfrm_state_alloc+0x24/0x2f0 net/xfrm/xfrm_state.c:733
xfrm_state_construct net/xfrm/xfrm_user.c:889 [inline]
xfrm_add_sa+0x17d1/0x4070 net/xfrm/xfrm_user.c:1019
xfrm_user_rcv_msg+0x7a3/0xab0 net/xfrm/xfrm_user.c:3501
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
xfrm_netlink_rcv+0x79/0x90 net/xfrm/xfrm_user.c:3523
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:729
____sys_sendmsg+0x505/0x830 net/socket.c:2614
page last free pid 6040 tgid 6038 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1395 [inline]
__free_frozen_pages+0xbc4/0xd30 mm/page_alloc.c:2895
stack_depot_save_flags+0x436/0x860 lib/stackdepot.c:727
kasan_save_stack mm/kasan/common.c:48 [inline]
kasan_save_track+0x4f/0x80 mm/kasan/common.c:68
poison_kmalloc_redzone mm/kasan/common.c:388 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:405
kasan_kmalloc include/linux/kasan.h:260 [inline]
__do_kmalloc_node mm/slub.c:4376 [inline]
__kvmalloc_node_noprof+0x30d/0x5f0 mm/slub.c:5067
kvmalloc_array_node_noprof include/linux/slab.h:1065 [inline]
btf_add_type kernel/bpf/btf.c:1621 [inline]
btf_check_all_metas kernel/bpf/btf.c:5270 [inline]
btf_parse_type_sec+0x5ae/0x24a0 kernel/bpf/btf.c:5402
btf_parse kernel/bpf/btf.c:5830 [inline]
btf_new_fd+0x40e/0xc90 kernel/bpf/btf.c:8036
__sys_bpf+0x406/0x870 kernel/bpf/syscall.c:6074
__do_sys_bpf kernel/bpf/syscall.c:6139 [inline]
__se_sys_bpf kernel/bpf/syscall.c:6137 [inline]
__x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:6137
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff8880545b9c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880545b9d00: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880545b9d80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
^
ffff8880545b9e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8880545b9e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: 90 nop
1: f3 0f 1e fa endbr64
5: 53 push %rbx
6: 48 89 fb mov %rdi,%rbx
9: 48 83 c7 18 add $0x18,%rdi
d: 48 8b 74 24 08 mov 0x8(%rsp),%rsi
12: e8 1a 9f 20 f6 call 0xf6209f31
17: 48 89 df mov %rbx,%rdi
1a: e8 72 36 21 f6 call 0xf6213691
1f: e8 0d 89 4a f6 call 0xf64a8931
24: fb sti
25: bf 01 00 00 00 mov $0x1,%edi
* 2a: e8 42 2e 13 f6 call 0xf6132e71 <-- trapping instruction
2f: 65 8b 05 cb d0 23 07 mov %gs:0x723d0cb(%rip),%eax # 0x723d101
36: 85 c0 test %eax,%eax
38: 74 07 je 0x41
3a: 5b pop %rbx
3b: c3 ret
3c: cc int3
3d: cc int3
3e: cc int3
3f: cc int3