syzbot

==================================================================
BUG: KASAN: slab-use-after-free in fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321
Read of size 8 at addr ffff88801d766d80 by task syz-executor/17614

CPU: 1 UID: 0 PID: 17614 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:
 <IRQ>
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:finish_task_switch+0x41a/0xbc0 kernel/sched/core.c:5245
Code: 03 00 00 41 c7 84 24 e0 0d 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 f0 c5 13 0a e8 6b dd 38 00 fb 4c 8b 65 c8 <49> 8d bc 24 c8 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc900032df960 EFLAGS: 00000202
RAX: 000000000007e349 RBX: ffff8880b873be60 RCX: 0000000080000001
RDX: 0000000000000000 RSI: ffffffff8dfad1b9 RDI: ffffffff8c2886a0
RBP: ffffc900032df9b0 R08: ffffffff902fd2f7 R09: 1ffffffff205fa5e
R10: dffffc0000000000 R11: fffffbfff205fa5f R12: ffff88807e0b9f00
R13: ffff8880b873be28 R14: dffffc0000000000 R15: 1ffff110170e77cc
 context_switch kernel/sched/core.c:5391 [inline]
 __schedule+0x1848/0x57a0 kernel/sched/core.c:7189
 __schedule_loop kernel/sched/core.c:7268 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7283
 do_nanosleep+0x193/0x5d0 kernel/time/hrtimer.c:2293
 hrtimer_nanosleep+0x18f/0x3a0 kernel/time/hrtimer.c:2339
 __do_sys_clock_nanosleep kernel/time/posix-timers.c:1391 [inline]
 __se_sys_clock_nanosleep+0x35b/0x3b0 kernel/time/posix-timers.c:1368
 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: 0033:0x7eff1755d68e
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 <c3> 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007ffdde8a5c98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: ffffffffffffffda RBX: 0000555574e7e500 RCX: 00007eff1755d68e
RDX: 00007ffdde8a5cf0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffdde8a5d5c R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000001388
R13: 00000000000927c0 R14: 0000000000082756 R15: 00007ffdde8a5db0
 </TASK>

Allocated by task 5635:
 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 15:
 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
 run_ksoftirqd+0x36/0x60 kernel/softirq.c:1076
 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160
 kthread+0x389/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

The buggy address belongs to the object at ffff88801d766d00
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 128 bytes inside of
 freed 192-byte region [ffff88801d766d00, ffff88801d766dc0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1d766
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 0xd2cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 4420802867, free_ts 0
 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]
 __kmalloc_cache_noprof+0x388/0x660 mm/slub.c:5415
 kmalloc_noprof include/linux/slab.h:950 [inline]
 kzalloc_noprof include/linux/slab.h:1188 [inline]
 call_usermodehelper_setup+0x8e/0x270 kernel/umh.c:362
 kobject_uevent_env+0x662/0x9e0 lib/kobject_uevent.c:631
 kset_register+0x1c0/0x230 lib/kobject.c:877
 bus_register+0x188/0x470 drivers/base/bus.c:958
 subsys_register+0x24/0x300 drivers/base/bus.c:1297
 clockevents_init_sysfs+0x12/0x20 kernel/time/clockevents.c:821
 do_one_initcall+0x250/0x870 init/main.c:1392
 do_initcall_level+0x10a/0x1a0 init/main.c:1454
 do_initcalls+0x59/0xa0 init/main.c:1470
page_owner free stack trace missing

Memory state around the buggy address:
 ffff88801d766c80: 00 00 00 00 00 00 00 06 fc fc fc fc fc fc fc fc
 ffff88801d766d00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88801d766d80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                   ^
 ffff88801d766e00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88801d766e80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	03 00                	add    (%rax),%eax
   2:	00 41 c7             	add    %al,-0x39(%rcx)
   5:	84 24 e0             	test   %ah,(%rax,%riz,8)
   8:	0d 00 00 00 00       	or     $0x0,%eax
   d:	00 00                	add    %al,(%rax)
   f:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
  14:	49 83 c4 48          	add    $0x48,%r12
  18:	4c 89 e7             	mov    %r12,%rdi
  1b:	e8 f0 c5 13 0a       	call   0xa13c610
  20:	e8 6b dd 38 00       	call   0x38dd90
  25:	fb                   	sti
  26:	4c 8b 65 c8          	mov    -0x38(%rbp),%r12
* 2a:	49 8d bc 24 c8 16 00 	lea    0x16c8(%r12),%rdi <-- trapping instruction
  31:	00
  32:	48 89 f8             	mov    %rdi,%rax
  35:	48 c1 e8 03          	shr    $0x3,%rax
  39:	42 0f b6 04 30       	movzbl (%rax,%r14,1),%eax
  3e:	84 c0                	test   %al,%al