==================================================================
BUG: KASAN: use-after-free in rcu_cblist_dequeue+0x6c/0xb0 kernel/rcu/rcu_segcblist.c:75
Read of size 8 at addr ffff88810099f590 by task syz.9.1930/8464
CPU: 0 PID: 8464 Comm: syz.9.1930 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Call Trace:
__dump_stack+0x21/0x24 lib/dump_stack.c:77
dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
__kasan_report mm/kasan/report.c:435 [inline]
kasan_report+0x100/0x140 mm/kasan/report.c:452
__asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
rcu_cblist_dequeue+0x6c/0xb0 kernel/rcu/rcu_segcblist.c:75
rcu_do_batch+0x448/0xaf0 kernel/rcu/tree.c:2484
rcu_core+0x50a/0xca0 kernel/rcu/tree.c:2735
rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2748
__do_softirq+0x255/0x563 kernel/softirq.c:309
asm_call_irq_on_stack+0xf/0x20
__run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
do_softirq_own_stack+0x60/0x80 arch/x86/kernel/irq_64.c:77
invoke_softirq kernel/softirq.c:405 [inline]
__irq_exit_rcu+0x128/0x150 kernel/softirq.c:435
irq_exit_rcu+0x9/0x10 kernel/softirq.c:447
sysvec_apic_timer_interrupt+0xbf/0xe0 arch/x86/kernel/apic/apic.c:1106
asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635
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+0x10b7/0x10d0 kernel/printk/printk.c:2557
Code: c3 e8 fd 7d 17 00 eb 98 e8 f6 7d 17 00 eb 91 e8 ef 7d 17 00 c6 05 28 25 9d 05 00 e8 33 55 00 00 48 89 5c 24 58 ff 74 24 58 9d 71 ff ff ff e8 cf 7d 17 00 e9 19 ff ff ff e8 25 9e 30 03 0f 1f
RSP: 0018:ffffc9000126f240 EFLAGS: 00000293
RAX: ffffffff814d8e19 RBX: 0000000000000293 RCX: ffff88811789a800
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: ffffc9000126f510 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200024de38 R12: dffffc0000000000
R13: fffff5200024de58 R14: 0000000000000000 R15: 0000000000000000
vprintk_emit+0x1a3/0x340 kernel/printk/printk.c:2069
vprintk_default+0x26/0x30 kernel/printk/printk.c:2086
vprintk_func+0x1a3/0x1e0 kernel/printk/printk_safe.c:401
printk+0xda/0x130 kernel/printk/printk.c:2117
selinux_netlink_send+0x5ed/0x830 security/selinux/hooks.c:5993
security_netlink_send+0x6b/0xa0 security/security.c:2012
netlink_sendmsg+0x7ad/0xb70 net/netlink/af_netlink.c:1909
sock_sendmsg_nosec net/socket.c:652 [inline]
__sock_sendmsg net/socket.c:664 [inline]
____sys_sendmsg+0x5be/0x8f0 net/socket.c:2377
___sys_sendmsg+0x236/0x2e0 net/socket.c:2431
__sys_sendmsg net/socket.c:2460 [inline]
__do_sys_sendmsg net/socket.c:2469 [inline]
__se_sys_sendmsg net/socket.c:2467 [inline]
__x64_sys_sendmsg+0x201/0x2d0 net/socket.c:2467
do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fca566dd559
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fca55135028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fca56963fa0 RCX: 00007fca566dd559
RDX: 000000002004c000 RSI: 0000200000001700 RDI: 0000000000000006
RBP: 00007fca56774b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fca56964038 R14: 00007fca56963fa0 R15: 00007ffd4c33ccb8
Allocated by task 8448:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track mm/kasan/common.c:45 [inline]
set_alloc_info mm/kasan/common.c:430 [inline]
____kasan_kmalloc mm/kasan/common.c:509 [inline]
__kasan_kmalloc+0xd4/0x100 mm/kasan/common.c:518
kasan_kmalloc include/linux/kasan.h:254 [inline]
__kmalloc+0x19f/0x330 mm/slub.c:4038
kmalloc include/linux/slab.h:560 [inline]
kzalloc include/linux/slab.h:667 [inline]
l2tp_session_create+0x39/0xb60 net/l2tp/l2tp_core.c:1616
pppol2tp_connect+0xbf5/0x1640 net/l2tp/l2tp_ppp.c:772
__sys_connect_file net/socket.c:1867 [inline]
__sys_connect+0x3ce/0x450 net/socket.c:1884
__do_sys_connect net/socket.c:1894 [inline]
__se_sys_connect net/socket.c:1891 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:1891
do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x61/0xcb
Freed by task 772:
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4a/0x70 mm/kasan/common.c:45
kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:370
____kasan_slab_free+0x125/0x160 mm/kasan/common.c:362
__kasan_slab_free+0x11/0x20 mm/kasan/common.c:370
kasan_slab_free include/linux/kasan.h:220 [inline]
slab_free_hook mm/slub.c:1600 [inline]
slab_free_freelist_hook+0xc5/0x190 mm/slub.c:1626
slab_free mm/slub.c:3208 [inline]
kfree+0xc0/0x270 mm/slub.c:4196
l2tp_session_free net/l2tp/l2tp_core.c:168 [inline]
l2tp_session_put+0xb2/0x1a0 net/l2tp/l2tp_core.c:193
l2tp_session_delete+0x3a9/0x4a0 net/l2tp/l2tp_core.c:1589
l2tp_tunnel_closeall net/l2tp/l2tp_core.c:1235 [inline]
l2tp_tunnel_del_work+0x180/0x3d0 net/l2tp/l2tp_core.c:1273
process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301
worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447
kthread+0x324/0x3b0 kernel/kthread.c:313
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
Last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
__kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
__call_rcu kernel/rcu/tree.c:2980 [inline]
call_rcu+0x11a/0x1090 kernel/rcu/tree.c:3054
pppol2tp_release+0x1e3/0x2b0 net/l2tp/l2tp_ppp.c:447
__sock_release net/socket.c:597 [inline]
sock_close+0xb8/0x200 net/socket.c:1287
__fput+0x2dc/0x730 fs/file_table.c:281
____fput+0x15/0x20 fs/file_table.c:314
task_work_run+0x127/0x190 kernel/task_work.c:189
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop+0xcb/0xe0 kernel/entry/common.c:175
exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:202
syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:277
do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56
entry_SYSCALL_64_after_hwframe+0x61/0xcb
Second to last potentially related work creation:
kasan_save_stack+0x3a/0x60 mm/kasan/common.c:38
__kasan_record_aux_stack+0xd2/0x100 mm/kasan/generic.c:348
kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:358
kvfree_call_rcu+0x117/0x670 kernel/rcu/tree.c:3539
drop_sysctl_table+0x2f5/0x430 fs/proc/proc_sysctl.c:1684
drop_sysctl_table+0x2e4/0x430 fs/proc/proc_sysctl.c:1687
unregister_sysctl_table+0x75/0x120 fs/proc/proc_sysctl.c:1722
unregister_net_sysctl_table+0x15/0x20 net/sysctl_net.c:127
__devinet_sysctl_unregister net/ipv4/devinet.c:2621 [inline]
devinet_sysctl_unregister net/ipv4/devinet.c:2649 [inline]
inetdev_destroy net/ipv4/devinet.c:326 [inline]
inetdev_event+0x788/0x1010 net/ipv4/devinet.c:1612
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410
call_netdevice_notifiers_info net/core/dev.c:2052 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
call_netdevice_notifiers net/core/dev.c:2078 [inline]
unregister_netdevice_many+0x100e/0x19f0 net/core/dev.c:10779
default_device_exit_batch+0x35e/0x3c0 net/core/dev.c:11299
ops_exit_list net/core/net_namespace.c:190 [inline]
cleanup_net+0x5fe/0xb80 net/core/net_namespace.c:609
process_one_work+0x6fd/0xbc0 kernel/workqueue.c:2301
worker_thread+0xa8e/0x13c0 kernel/workqueue.c:2447
kthread+0x324/0x3b0 kernel/kthread.c:313
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
The buggy address belongs to the object at ffff88810099f400
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 400 bytes inside of
512-byte region [ffff88810099f400, ffff88810099f600)
The buggy address belongs to the page:
page:ffffea0004026700 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10099c
head:ffffea0004026700 order:2 compound_mapcount:0 compound_pincount:0
flags: 0x4000000000010200(slab|head)
raw: 4000000000010200 dead000000000100 dead000000000122 ffff888100043080
raw: 0000000000000000 0000000000100010 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 280, ts 30698659312, free_ts 30687794827
set_page_owner include/linux/page_owner.h:35 [inline]
post_alloc_hook mm/page_alloc.c:2456 [inline]
prep_new_page+0x176/0x190 mm/page_alloc.c:2462
get_page_from_freelist+0x225f/0x23f0 mm/page_alloc.c:4254
__alloc_pages_nodemask+0x29a/0x640 mm/page_alloc.c:5384
alloc_slab_page mm/slub.c:-1 [inline]
allocate_slab mm/slub.c:1813 [inline]
new_slab+0x84/0x3f0 mm/slub.c:1874
new_slab_objects mm/slub.c:2632 [inline]
___slab_alloc+0x2f8/0x4c0 mm/slub.c:2796
__slab_alloc+0x63/0xa0 mm/slub.c:2836
slab_alloc_node mm/slub.c:2918 [inline]
slab_alloc mm/slub.c:2960 [inline]
kmem_cache_alloc_trace+0x1a8/0x2e0 mm/slub.c:2977
kmalloc include/linux/slab.h:555 [inline]
kzalloc include/linux/slab.h:667 [inline]
inetdev_init+0x81/0x490 net/ipv4/devinet.c:259
inetdev_event+0x1f4/0x1010 net/ipv4/devinet.c:1544
notifier_call_chain kernel/notifier.c:83 [inline]
raw_notifier_call_chain+0x90/0x100 kernel/notifier.c:410
call_netdevice_notifiers_info net/core/dev.c:2052 [inline]
call_netdevice_notifiers_extack net/core/dev.c:2064 [inline]
call_netdevice_notifiers+0x119/0x190 net/core/dev.c:2078
register_netdevice+0x100a/0x13a0 net/core/dev.c:10099
veth_newlink+0x696/0xb60 drivers/net/veth.c:1360
__rtnl_newlink net/core/rtnetlink.c:3494 [inline]
rtnl_newlink+0x1307/0x1830 net/core/rtnetlink.c:3542
rtnetlink_rcv_msg+0x9e9/0xca0 net/core/rtnetlink.c:5622
netlink_rcv_skb+0x1e9/0x430 net/netlink/af_netlink.c:2508
page last free stack trace:
reset_page_owner include/linux/page_owner.h:28 [inline]
free_pages_prepare mm/page_alloc.c:1349 [inline]
__free_pages_ok+0x80b/0x830 mm/page_alloc.c:1629
free_the_page mm/page_alloc.c:5445 [inline]
__free_pages+0xd8/0x390 mm/page_alloc.c:5454
__free_slab+0xcf/0x190 mm/slub.c:1899
free_slab mm/slub.c:1914 [inline]
discard_slab mm/slub.c:1920 [inline]
unfreeze_partials+0x150/0x180 mm/slub.c:2415
put_cpu_partial+0xc1/0x180 mm/slub.c:2451
__slab_free+0x2c9/0x3a0 mm/slub.c:3100
do_slab_free mm/slub.c:3196 [inline]
___cache_free+0x10e/0x130 mm/slub.c:3215
qlink_free+0x50/0x90 mm/kasan/quarantine.c:157
qlist_free_all+0x5f/0xb0 mm/kasan/quarantine.c:176
kasan_quarantine_reduce+0x14a/0x160 mm/kasan/quarantine.c:283
__kasan_slab_alloc+0x2f/0xe0 mm/kasan/common.c:440
kasan_slab_alloc include/linux/kasan.h:244 [inline]
slab_post_alloc_hook+0x5d/0x2f0 mm/slab.h:580
slab_alloc_node mm/slub.c:2952 [inline]
slab_alloc mm/slub.c:2960 [inline]
__kmalloc_track_caller+0x176/0x310 mm/slub.c:4541
kvasprintf+0xe3/0x1a0 lib/kasprintf.c:25
kvasprintf_const+0xf2/0x240 lib/kasprintf.c:49
kobject_set_name_vargs+0x61/0x110 lib/kobject.c:297
Memory state around the buggy address:
ffff88810099f480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88810099f500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88810099f580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88810099f600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88810099f680: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
0: c3 ret
1: e8 fd 7d 17 00 call 0x177e03
6: eb 98 jmp 0xffffffa0
8: e8 f6 7d 17 00 call 0x177e03
d: eb 91 jmp 0xffffffa0
f: e8 ef 7d 17 00 call 0x177e03
14: c6 05 28 25 9d 05 00 movb $0x0,0x59d2528(%rip) # 0x59d2543
1b: e8 33 55 00 00 call 0x5553
20: 48 89 5c 24 58 mov %rbx,0x58(%rsp)
25: ff 74 24 58 push 0x58(%rsp)
29: 9d popf
* 2a: e9 71 ff ff ff jmp 0xffffffa0 <-- trapping instruction
2f: e8 cf 7d 17 00 call 0x177e03
34: e9 19 ff ff ff jmp 0xffffff52
39: e8 25 9e 30 03 call 0x3309e63
3e: 0f .byte 0xf
3f: 1f (bad)