================================================================== BUG: KASAN: use-after-free in rose_get_neigh+0x17e/0x550 net/rose/rose_route.c:692 Read of size 1 at addr ffff888056122430 by task syz.2.1227/8942 CPU: 0 PID: 8942 Comm: syz.2.1227 Not tainted 6.1.136-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Call Trace: dump_stack_lvl+0x168/0x22e lib/dump_stack.c:106 print_address_description mm/kasan/report.c:316 [inline] print_report+0xa8/0x220 mm/kasan/report.c:427 kasan_report+0x10b/0x140 mm/kasan/report.c:531 rose_get_neigh+0x17e/0x550 net/rose/rose_route.c:692 rose_connect+0x412/0x1380 net/rose/af_rose.c:816 __sys_connect_file net/socket.c:2011 [inline] __sys_connect+0x389/0x410 net/socket.c:2028 __do_sys_connect net/socket.c:2038 [inline] __se_sys_connect net/socket.c:2035 [inline] __x64_sys_connect+0x76/0x80 net/socket.c:2035 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7ff81698e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ff81774e038 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffffda RBX: 00007ff816bb5fa0 RCX: 00007ff81698e969 RDX: 000000000000001c RSI: 0000200000000240 RDI: 0000000000000008 RBP: 00007ff816a10ab1 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007ff816bb5fa0 R15: 00007ffffd063d38 Allocated by task 8114: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0x8e/0xa0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:563 [inline] rose_add_node+0x227/0xdb0 net/rose/rose_route.c:85 rose_rt_ioctl+0xa4c/0xe90 net/rose/rose_route.c:747 rose_ioctl+0x27a/0x790 net/rose/af_rose.c:1380 sock_do_ioctl+0xd3/0x2f0 net/socket.c:1204 sock_ioctl+0x4ed/0x6e0 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 8942: kasan_save_stack mm/kasan/common.c:45 [inline] kasan_set_track+0x4b/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3674 rose_rt_device_down+0x3e5/0x430 net/rose/rose_route.c:522 rose_device_event+0x600/0x690 net/rose/af_rose.c:248 notifier_call_chain kernel/notifier.c:87 [inline] raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:455 call_netdevice_notifiers_extack net/core/dev.c:2039 [inline] call_netdevice_notifiers net/core/dev.c:2053 [inline] __dev_notify_flags+0x178/0x2d0 net/core/dev.c:-1 dev_change_flags+0xe3/0x1a0 net/core/dev.c:8702 dev_ifsioc+0x159/0xe90 net/core/dev_ioctl.c:327 dev_ioctl+0x578/0xea0 net/core/dev_ioctl.c:588 sock_do_ioctl+0x222/0x2f0 net/socket.c:1218 sock_ioctl+0x4ed/0x6e0 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 The buggy address belongs to the object at ffff888056122400 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 48 bytes inside of 512-byte region [ffff888056122400, ffff888056122600) The buggy address belongs to the physical page: page:ffffea0001584800 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888056120c00 pfn:0x56120 head:ffffea0001584800 order:2 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffffea0001630808 ffffea00015b8408 ffff888017441c80 raw: ffff888056120c00 0000000000100004 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 4260, tgid 4260 (syz-executor), ts 76743452833, free_ts 76741354295 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5606 alloc_slab_page+0x5d/0x160 mm/slub.c:1794 allocate_slab mm/slub.c:1939 [inline] new_slab+0x87/0x2c0 mm/slub.c:1992 ___slab_alloc+0xbc6/0x1220 mm/slub.c:3180 __slab_alloc mm/slub.c:3279 [inline] slab_alloc_node mm/slub.c:3364 [inline] __kmem_cache_alloc_node+0x1a0/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa0/0x240 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] kzalloc include/linux/slab.h:699 [inline] fib6_info_alloc+0x2e/0xe0 net/ipv6/ip6_fib.c:156 ip6_route_info_create+0x44f/0x1210 net/ipv6/route.c:3794 ip6_route_add+0x24/0x130 net/ipv6/route.c:3890 addrconf_prefix_route+0x20d/0x2b0 net/ipv6/addrconf.c:2443 inet6_addr_add+0x4fe/0x9b0 net/ipv6/addrconf.c:3017 inet6_rtm_newaddr+0x617/0x870 net/ipv6/addrconf.c:4976 rtnetlink_rcv_msg+0x79b/0xed0 net/core/rtnetlink.c:6153 netlink_rcv_skb+0x1de/0x420 net/netlink/af_netlink.c:2493 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3384 free_unref_page+0x2e/0x3f0 mm/page_alloc.c:3479 __stack_depot_save+0x435/0x460 lib/stackdepot.c:506 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x60/0x70 mm/kasan/common.c:52 kasan_save_free_info+0x2d/0x50 mm/kasan/generic.c:516 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236 kasan_slab_free include/linux/kasan.h:177 [inline] slab_free_hook mm/slub.c:1724 [inline] slab_free_freelist_hook+0x131/0x1a0 mm/slub.c:1750 slab_free mm/slub.c:3661 [inline] __kmem_cache_free+0xb6/0x1f0 mm/slub.c:3674 skb_free_head net/core/skbuff.c:762 [inline] skb_release_data+0x5db/0x7c0 net/core/skbuff.c:791 skb_release_all net/core/skbuff.c:856 [inline] __kfree_skb net/core/skbuff.c:870 [inline] kfree_skb_reason+0x163/0x370 net/core/skbuff.c:893 kfree_skb include/linux/skbuff.h:1220 [inline] xfrmi_xmit+0xc00/0x1680 net/xfrm/xfrm_interface_core.c:574 __netdev_start_xmit include/linux/netdevice.h:4896 [inline] netdev_start_xmit include/linux/netdevice.h:4910 [inline] xmit_one net/core/dev.c:3658 [inline] dev_hard_start_xmit+0x262/0x870 net/core/dev.c:3674 __dev_queue_xmit+0x1bf1/0x3760 net/core/dev.c:4334 neigh_output include/net/neighbour.h:544 [inline] ip6_finish_output2+0xda2/0x1590 net/ipv6/ip6_output.c:138 __ip6_finish_output net/ipv6/ip6_output.c:205 [inline] ip6_finish_output+0x5d3/0xa60 net/ipv6/ip6_output.c:216 dst_output include/net/dst.h:453 [inline] NF_HOOK include/linux/netfilter.h:302 [inline] ndisc_send_skb+0xbfb/0x1510 net/ipv6/ndisc.c:513 Memory state around the buggy address: ffff888056122300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888056122380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888056122400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888056122480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888056122500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb 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