==================================================================
BUG: KASAN: slab-use-after-free in fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321
Read of size 8 at addr ffff88806b501c80 by task syz-executor/30214
CPU: 0 UID: 0 PID: 30214 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Call Trace:
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_address_description+0x55/0x1e0 mm/kasan/report.c:378
print_report+0x58/0x70 mm/kasan/report.c:482
kasan_report+0x117/0x150 mm/kasan/report.c:595
fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321
__fib_lookup+0x106/0x210 net/ipv4/fib_rules.c:96
ip_route_output_key_hash_rcu+0x294/0x2720 net/ipv4/route.c:2811
ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2702
icmp_route_lookup+0x50a/0xb50 net/ipv4/icmp.c:520
__icmp_send+0x1010/0x1710 net/ipv4/icmp.c:958
ipv4_send_dest_unreach net/ipv4/route.c:1253 [inline]
ipv4_link_failure+0x64d/0xa50 net/ipv4/route.c:1260
dst_link_failure include/net/dst.h:438 [inline]
arp_error_report+0x118/0x160 net/ipv4/arp.c:296
neigh_invalidate+0x243/0x470 net/core/neighbour.c:1077
neigh_timer_handler+0xc01/0x12b0 net/core/neighbour.c:1169
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x225/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:insert_entry fs/proc/proc_sysctl.c:164 [inline]
RIP: 0010:insert_header+0xb55/0x1260 fs/proc/proc_sysctl.c:252
Code: 48 c1 e8 03 80 3c 08 00 74 12 4c 89 f7 e8 43 7a c2 ff 48 b9 00 00 00 00 00 fc ff df 4d 8b 36 4c 89 f0 48 c1 e8 03 80 3c 08 00 <74> 12 4c 89 f7 e8 21 7a c2 ff 48 b9 00 00 00 00 00 fc ff df 4d 8b
RSP: 0018:ffffc90002e26c80 EFLAGS: 00000246
RAX: 1ffff11010eba000 RBX: ffff8880875d0138 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: ffff88804d5bb458 RDI: ffffffff8cddf3e0
RBP: ffffffff8cddf3e0 R08: ffff8880875d020f R09: 0000000000000000
R10: ffff8880875d0200 R11: ffffed1010eba042 R12: ffff88804d5bb458
R13: 000000000000000a R14: ffff8880875d0000 R15: ffff88804d5bb458
__register_sysctl_table+0x121a/0x1370 fs/proc/proc_sysctl.c:1399
neigh_sysctl_register+0x9b1/0xa90 net/core/neighbour.c:3915
addrconf_sysctl_register+0xb3/0x1c0 net/ipv6/addrconf.c:7396
ipv6_add_dev+0xd26/0x13a0 net/ipv6/addrconf.c:460
addrconf_notify+0x771/0x1050 net/ipv6/addrconf.c:3679
notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85
call_netdevice_notifiers_extack net/core/dev.c:2288 [inline]
call_netdevice_notifiers net/core/dev.c:2302 [inline]
register_netdevice+0x18db/0x1f00 net/core/dev.c:11474
rtnl_newlink_create+0x310/0xb00 net/core/rtnetlink.c:3905
__rtnl_newlink net/core/rtnetlink.c:4036 [inline]
rtnl_newlink+0x167f/0x1bd0 net/core/rtnetlink.c:4151
rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7068
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
__sys_sendto+0x672/0x710 net/socket.c:2266
__do_sys_sendto net/socket.c:2273 [inline]
__se_sys_sendto net/socket.c:2269 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2269
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb80695d68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007fff79146078 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000555569d33500 RCX: 00007fb80695d68e
RDX: 000000000000004c RSI: 00007fb807744670 RDI: 0000000000000003
RBP: 0000000000000001 R08: 00007fff791460f4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 00007fb807744670 R15: 0000000000000000
Allocated by task 19536:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
poison_kmalloc_redzone mm/kasan/common.c:398 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:415
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5296 [inline]
__kmalloc_node_track_caller_noprof+0x4d7/0x7b0 mm/slub.c:5408
kmemdup_noprof+0x2b/0x70 mm/util.c:138
kmemdup_noprof include/linux/fortify-string.h:763 [inline]
fib_rules_register+0x2f/0x400 net/core/fib_rules.c:170
fib4_rules_init+0x21/0x160 net/ipv4/fib_rules.c:508
ip_fib_net_init net/ipv4/fib_frontend.c:1578 [inline]
fib_net_init+0x17a/0x3e0 net/ipv4/fib_frontend.c:1628
ops_init+0x35d/0x5d0 net/core/net_namespace.c:137
setup_net+0x118/0x350 net/core/net_namespace.c:446
copy_net_ns+0x4f9/0x720 net/core/net_namespace.c:579
create_new_namespaces+0x3f0/0x6b0 kernel/nsproxy.c:132
unshare_nsproxy_namespaces+0x149/0x190 kernel/nsproxy.c:234
ksys_unshare+0x57d/0xa00 kernel/fork.c:3242
__do_sys_unshare kernel/fork.c:3316 [inline]
__se_sys_unshare kernel/fork.c:3314 [inline]
__x64_sys_unshare+0x38/0x50 kernel/fork.c:3314
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 5919:
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2689 [inline]
__rcu_free_sheaf_prepare+0x12d/0x2a0 mm/slub.c:2940
rcu_free_sheaf+0x31/0x200 mm/slub.c:5850
rcu_do_batch kernel/rcu/tree.c:2617 [inline]
rcu_core+0x78b/0x10a0 kernel/rcu/tree.c:2869
handle_softirqs+0x225/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
The buggy address belongs to the object at ffff88806b501c00
which belongs to the cache kmalloc-192 of size 192
The buggy address is located 128 bytes inside of
freed 192-byte region [ffff88806b501c00, ffff88806b501cc0)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6b501
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000000 ffff88813fe163c0 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 18273, tgid 18272 (syz.2.3638), ts 557605203093, free_ts 553152416542
set_page_owner include/linux/page_owner.h:32 [inline]
post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853
prep_new_page mm/page_alloc.c:1861 [inline]
get_page_from_freelist+0x24ae/0x2530 mm/page_alloc.c:3941
__alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221
alloc_slab_page mm/slub.c:3278 [inline]
allocate_slab+0x77/0x660 mm/slub.c:3467
new_slab mm/slub.c:3525 [inline]
refill_objects+0x336/0x3d0 mm/slub.c:7272
refill_sheaf mm/slub.c:2816 [inline]
__pcs_replace_empty_main+0x320/0x720 mm/slub.c:4652
alloc_from_pcs mm/slub.c:4750 [inline]
slab_alloc_node mm/slub.c:4884 [inline]
__do_kmalloc_node mm/slub.c:5295 [inline]
__kmalloc_noprof+0x464/0x750 mm/slub.c:5308
kmalloc_noprof include/linux/slab.h:954 [inline]
kzalloc_noprof include/linux/slab.h:1188 [inline]
hash_netportnet6_resize+0xcd3/0x1df0 net/netfilter/ipset/ip_set_hash_gen.h:728
call_ad+0x439/0xb50 net/netfilter/ipset/ip_set_core.c:1758
ip_set_ad+0x824/0x9d0 net/netfilter/ipset/ip_set_core.c:1842
nfnetlink_rcv_msg+0xcc2/0x12b0 net/netfilter/nfnetlink.c:300
netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2556
nfnetlink_rcv+0x2b9/0x28c0 net/netfilter/nfnetlink.c:667
netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1345
netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1900
sock_sendmsg_nosec net/socket.c:787 [inline]
__sock_sendmsg net/socket.c:802 [inline]
____sys_sendmsg+0x9b9/0xa20 net/socket.c:2699
page last free pid 18200 tgid 18199 stack trace:
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1397 [inline]
__free_frozen_pages+0xc0d/0xd20 mm/page_alloc.c:2938
tlb_batch_list_free mm/mmu_gather.c:161 [inline]
tlb_finish_mmu+0x13e/0x220 mm/mmu_gather.c:552
exit_mmap+0x4b2/0x9f0 mm/mmap.c:1313
__mmput+0x118/0x420 kernel/fork.c:1178
exit_mm+0x1e4/0x2b0 kernel/exit.c:582
do_exit+0x6cd/0x2360 kernel/exit.c:964
do_group_exit+0x22d/0x2f0 kernel/exit.c:1119
get_signal+0x121b/0x12c0 kernel/signal.c:3038
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0xa9/0x6b0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Memory state around the buggy address:
ffff88806b501b80: 00 00 00 00 00 00 00 06 fc fc fc fc fc fc fc fc
ffff88806b501c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88806b501c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
^
ffff88806b501d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffff88806b501d80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
0: 48 c1 e8 03 shr $0x3,%rax
4: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1)
8: 74 12 je 0x1c
a: 4c 89 f7 mov %r14,%rdi
d: e8 43 7a c2 ff call 0xffc27a55
12: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
19: fc ff df
1c: 4d 8b 36 mov (%r14),%r14
1f: 4c 89 f0 mov %r14,%rax
22: 48 c1 e8 03 shr $0x3,%rax
26: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1)
* 2a: 74 12 je 0x3e <-- trapping instruction
2c: 4c 89 f7 mov %r14,%rdi
2f: e8 21 7a c2 ff call 0xffc27a55
34: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx
3b: fc ff df
3e: 4d rex.WRB
3f: 8b .byte 0x8b