================================================================== BUG: KASAN: slab-use-after-free in fib_rules_lookup+0x15e/0xeb0 net/core/fib_rules.c:321 Read of size 8 at addr ffff8880299c6380 by task ktimers/1/30 CPU: 1 UID: 0 PID: 30 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(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:456 [inline] arp_error_report+0x118/0x160 net/ipv4/arp.c:296 neigh_invalidate+0x243/0x470 net/core/neighbour.c:1077 neigh_timer_handler+0xc0d/0x12c0 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+0x67b/0x9b0 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+0x1d9/0x6c0 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] run_ktimerd+0x69/0x100 kernel/softirq.c:1155 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160 kthread+0x388/0x470 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 Allocated by task 15572: 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:5360 [inline] __kmalloc_node_track_caller_noprof+0x57f/0x7c0 mm/slub.c:5495 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:3267 __do_sys_unshare kernel/fork.c:3341 [inline] __se_sys_unshare kernel/fork.c:3339 [inline] __x64_sys_unshare+0x38/0x50 kernel/fork.c:3339 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 12326: 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:2703 [inline] slab_free_freelist_hook mm/slub.c:2732 [inline] slab_free_bulk mm/slub.c:6437 [inline] kmem_cache_free_bulk+0x309/0x1260 mm/slub.c:7174 kfree_bulk include/linux/slab.h:891 [inline] kvfree_rcu_bulk+0xc6/0x190 mm/slab_common.c:1502 kfree_rcu_work+0xe8/0x160 mm/slab_common.c:1580 process_one_work+0x93a/0x12b0 kernel/workqueue.c:3326 process_scheduled_works kernel/workqueue.c:3409 [inline] worker_thread+0xb05/0x10d0 kernel/workqueue.c:3490 kthread+0x388/0x470 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 Last potentially related work creation: kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556 kvfree_call_rcu+0x90/0x3c0 mm/slab_common.c:1970 ops_exit_rtnl_list net/core/net_namespace.c:181 [inline] ops_undo_list+0x319/0x8d0 net/core/net_namespace.c:248 cleanup_net+0x575/0x810 net/core/net_namespace.c:702 process_one_work+0x93a/0x12b0 kernel/workqueue.c:3326 process_scheduled_works kernel/workqueue.c:3409 [inline] worker_thread+0xb05/0x10d0 kernel/workqueue.c:3490 kthread+0x388/0x470 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 ffff8880299c6300 which belongs to the cache kmalloc-192 of size 192 The buggy address is located 128 bytes inside of freed 192-byte region [ffff8880299c6300, ffff8880299c63c0) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x299c6 flags: 0x80000000000000(node=0|zone=1) page_type: f5(slab) raw: 0080000000000000 ffff88813fe1f3c0 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 5801, tgid 5801 (syz-executor), ts 67748432664, free_ts 67747881414 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0x2639/0x26b0 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5304 alloc_slab_page mm/slub.c:3292 [inline] allocate_slab+0x79/0x5e0 mm/slub.c:3406 new_slab mm/slub.c:3452 [inline] refill_objects+0x2d8/0x350 mm/slub.c:7336 refill_sheaf mm/slub.c:2830 [inline] __pcs_replace_empty_main+0x330/0x690 mm/slub.c:4701 alloc_from_pcs mm/slub.c:4799 [inline] slab_alloc_node mm/slub.c:4931 [inline] __do_kmalloc_node mm/slub.c:5359 [inline] __kmalloc_flags_noprof+0x653/0x830 mm/slub.c:5552 _kmalloc_flags_noprof mm/slab.h:38 [inline] alloc_slab_obj_exts+0xb7/0x230 mm/slub.c:2179 __memcg_slab_post_alloc_hook+0x602/0xf60 mm/memcontrol.c:3587 memcg_slab_post_alloc_hook mm/slub.c:2473 [inline] slab_post_alloc_hook mm/slub.c:4629 [inline] slab_alloc_node mm/slub.c:4943 [inline] kmem_cache_alloc_lru_noprof+0x410/0x650 mm/slub.c:4976 __d_alloc+0x37/0x6f0 fs/dcache.c:1902 d_alloc_parallel+0xde/0x16c0 fs/dcache.c:2761 lookup_open fs/namei.c:4423 [inline] open_last_lookups fs/namei.c:4608 [inline] path_openat+0xbf0/0x3850 fs/namei.c:4856 do_file_open+0x23e/0x4a0 fs/namei.c:4888 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 page last free pid 5801 tgid 5801 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0x10de/0x11c0 mm/page_alloc.c:2950 __slab_free+0x252/0x2a0 mm/slub.c:5765 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4610 [inline] slab_alloc_node mm/slub.c:4943 [inline] __do_kmalloc_node mm/slub.c:5359 [inline] __kmalloc_noprof+0x3b6/0x780 mm/slub.c:5385 _kmalloc_noprof include/linux/slab.h:973 [inline] _kzalloc_noprof include/linux/slab.h:1290 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x2ad/0x570 security/tomoyo/realpath.c:80 tomoyo_path_perm+0x318/0x560 security/tomoyo/file.c:836 tomoyo_path_symlink+0xab/0xf0 security/tomoyo/tomoyo.c:212 security_path_symlink+0x16f/0x360 security/security.c:1502 filename_symlinkat+0x134/0x420 fs/namei.c:5679 __do_sys_symlinkat fs/namei.c:5701 [inline] __se_sys_symlinkat+0x4e/0x2b0 fs/namei.c:5696 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 Memory state around the buggy address: ffff8880299c6280: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff8880299c6300: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880299c6380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8880299c6400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880299c6480: 00 00 00 00 00 00 00 05 fc fc fc fc fc fc fc fc 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