==================================================================
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 ffff888029da4470 by task syz.3.680/8457
CPU: 0 UID: 0 PID: 8457 Comm: syz.3.680 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_timer_handler+0x18f/0xa00 net/xfrm/xfrm_state.c:716
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x529/0xc60 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:check_kcov_mode kernel/kcov.c:185 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x31/0x70 kernel/kcov.c:217
Code: 24 65 48 8b 0c 25 08 80 a0 92 65 8b 15 c8 d1 e0 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c <8b> 91 18 16 00 00 83 fa 02 75 21 48 8b 91 20 16 00 00 48 8b 32 48
RSP: 0018:ffffc9001c4472c8 EFLAGS: 00000246
RAX: ffffffff8211c8e7 RBX: ffffea00019e70c0 RCX: ffff888033de0000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000f4000000
RBP: 0000000000000001 R08: ffffea00019e70c7 R09: 1ffffd400033ce18
R10: dffffc0000000000 R11: fffff9400033ce19 R12: 0000000000000000
R13: dffffc0000000000 R14: 80000000679c3000 R15: ffffea00019e70c0
__folio_rmap_sanity_checks+0x67/0x7d0 include/linux/rmap.h:411
__folio_remove_rmap mm/rmap.c:1694 [inline]
folio_remove_rmap_ptes+0x3b/0xaf0 mm/rmap.c:1804
zap_present_folio_ptes mm/memory.c:1523 [inline]
zap_present_ptes mm/memory.c:1581 [inline]
do_zap_pte_range mm/memory.c:1682 [inline]
zap_pte_range mm/memory.c:1726 [inline]
zap_pmd_range mm/memory.c:1818 [inline]
zap_pud_range mm/memory.c:1847 [inline]
zap_p4d_range mm/memory.c:1868 [inline]
unmap_page_range+0x1f7f/0x4370 mm/memory.c:1889
unmap_single_vma mm/memory.c:1932 [inline]
unmap_vmas+0x399/0x580 mm/memory.c:1976
exit_mmap+0x248/0xb50 mm/mmap.c:1280
__mmput+0x118/0x420 kernel/fork.c:1130
exit_mm+0x1da/0x2c0 kernel/exit.c:582
do_exit+0x648/0x2300 kernel/exit.c:949
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f541538eba9
Code: Unable to access opcode bytes at 0x7f541538eb7f.
RSP: 002b:00007f54131d30e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f54155d6278 RCX: 00007f541538eba9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f54155d6278
RBP: 00007f54155d6270 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f54155d6308 R14: 00007fff2f2cf3f0 R15: 00007fff2f2cf4d8
Allocated by task 7047:
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+0x7a0/0xab0 net/xfrm/xfrm_user.c:3501
netlink_rcv_skb+0x205/0x470 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+0x82c/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+0x21c/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 5934:
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+0x3fc/0x770 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 ffff888029da4440
which belongs to the cache xfrm_state of size 928
The buggy address is located 48 bytes inside of
freed 928-byte region [ffff888029da4440, ffff888029da47e0)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888029da4440 pfn:0x29da4
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 ffff88801b3673c0 dead000000000122 0000000000000000
raw: ffff888029da4440 00000000800f000e 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b3673c0 dead000000000122 0000000000000000
head: ffff888029da4440 00000000800f000e 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000a76901 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 6445, tgid 6443 (syz.1.142), ts 95849344134, free_ts 95660652317
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+0x7a0/0xab0 net/xfrm/xfrm_user.c:3501
netlink_rcv_skb+0x205/0x470 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+0x82c/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+0x21c/0x270 net/socket.c:729
____sys_sendmsg+0x505/0x830 net/socket.c:2614
page last free pid 6424 tgid 6422 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
free_large_kmalloc+0x13a/0x1f0 mm/slub.c:4820
device_release+0x99/0x1c0 drivers/base/core.c:-1
kobject_cleanup lib/kobject.c:689 [inline]
kobject_release lib/kobject.c:720 [inline]
kref_put include/linux/kref.h:65 [inline]
kobject_put+0x22b/0x480 lib/kobject.c:737
netdev_run_todo+0xd2e/0xea0 net/core/dev.c:11513
tun_detach drivers/net/tun.c:640 [inline]
tun_chr_close+0x13c/0x1c0 drivers/net/tun.c:3433
__fput+0x449/0xa70 fs/file_table.c:468
task_work_run+0x1d1/0x260 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x6b5/0x2300 kernel/exit.c:961
do_group_exit+0x21c/0x2d0 kernel/exit.c:1102
get_signal+0x1286/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:40
exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff888029da4300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff888029da4380: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888029da4400: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
^
ffff888029da4480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff888029da4500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
0: 24 65 and $0x65,%al
2: 48 8b 0c 25 08 80 a0 mov 0xffffffff92a08008,%rcx
9: 92
a: 65 8b 15 c8 d1 e0 10 mov %gs:0x10e0d1c8(%rip),%edx # 0x10e0d1d9
11: 81 e2 00 01 ff 00 and $0xff0100,%edx
17: 74 11 je 0x2a
19: 81 fa 00 01 00 00 cmp $0x100,%edx
1f: 75 35 jne 0x56
21: 83 b9 3c 16 00 00 00 cmpl $0x0,0x163c(%rcx)
28: 74 2c je 0x56
* 2a: 8b 91 18 16 00 00 mov 0x1618(%rcx),%edx <-- trapping instruction
30: 83 fa 02 cmp $0x2,%edx
33: 75 21 jne 0x56
35: 48 8b 91 20 16 00 00 mov 0x1620(%rcx),%rdx
3c: 48 8b 32 mov (%rdx),%rsi
3f: 48 rex.W