================================================================== BUG: KASAN: slab-out-of-bounds in _decode_session6+0x124c/0x1370 net/ipv6/xfrm6_policy.c:159 Read of size 1 at addr ffff8801c774f387 by task syz-executor4/16732 CPU: 0 PID: 16732 Comm: syz-executor4 Not tainted 4.14.73+ #15 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x11b lib/dump_stack.c:53 print_address_description+0x60/0x22b mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report.cold.6+0x11b/0x2dd mm/kasan/report.c:409 _decode_session6+0x124c/0x1370 net/ipv6/xfrm6_policy.c:159 __xfrm_decode_session+0x64/0x100 net/xfrm/xfrm_policy.c:2426 xfrm_decode_session include/net/xfrm.h:1201 [inline] vti6_tnl_xmit+0x31b/0x1580 net/ipv6/ip6_vti.c:550 __netdev_start_xmit include/linux/netdevice.h:4023 [inline] netdev_start_xmit include/linux/netdevice.h:4032 [inline] xmit_one net/core/dev.c:2987 [inline] dev_hard_start_xmit+0x191/0x890 net/core/dev.c:3003 __dev_queue_xmit+0x13d9/0x1f40 net/core/dev.c:3503 __bpf_tx_skb net/core/filter.c:1708 [inline] __bpf_redirect_common net/core/filter.c:1746 [inline] __bpf_redirect+0x5b0/0x990 net/core/filter.c:1753 ____bpf_clone_redirect net/core/filter.c:1786 [inline] bpf_clone_redirect+0x1d4/0x2b0 net/core/filter.c:1758 ___bpf_prog_run+0x248e/0x5c70 kernel/bpf/core.c:1012 Allocated by task 16732: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.1+0x4f/0xd0 mm/kasan/kasan.c:551 slab_post_alloc_hook mm/slab.h:442 [inline] slab_alloc_node mm/slub.c:2723 [inline] slab_alloc mm/slub.c:2731 [inline] __kmalloc_track_caller+0x104/0x300 mm/slub.c:4288 __kmalloc_reserve.isra.8+0x2f/0xc0 net/core/skbuff.c:137 pskb_expand_head+0x117/0xb30 net/core/skbuff.c:1458 skb_ensure_writable+0x237/0x2e0 net/core/skbuff.c:5025 __bpf_try_make_writable net/core/filter.c:1403 [inline] bpf_try_make_writable net/core/filter.c:1409 [inline] bpf_try_make_head_writable net/core/filter.c:1417 [inline] ____bpf_clone_redirect net/core/filter.c:1780 [inline] bpf_clone_redirect+0x119/0x2b0 net/core/filter.c:1758 ___bpf_prog_run+0x248e/0x5c70 kernel/bpf/core.c:1012 Freed by task 15022: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:524 slab_free_hook mm/slub.c:1389 [inline] slab_free_freelist_hook mm/slub.c:1410 [inline] slab_free mm/slub.c:2966 [inline] kfree+0xf5/0x310 mm/slub.c:3897 load_elf_binary+0x1c56/0x4530 fs/binfmt_elf.c:1097 search_binary_handler+0x13f/0x6c0 fs/exec.c:1638 exec_binprm fs/exec.c:1680 [inline] do_execveat_common.isra.14+0x1109/0x1d60 fs/exec.c:1802 do_execve+0x2c/0x40 fs/exec.c:1847 call_usermodehelper_exec_async+0x289/0x4b0 kernel/umh.c:100 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:402 The buggy address belongs to the object at ffff8801c774f180 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 7 bytes to the right of 512-byte region [ffff8801c774f180, ffff8801c774f380) The buggy address belongs to the page: page:ffffea00071dd380 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000008100(slab|head) raw: 4000000000008100 0000000000000000 0000000000000000 00000001800c000c raw: ffffea00075a3a80 0000000c00000003 ffff8801da802c00 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c774f280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801c774f300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8801c774f380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8801c774f400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801c774f480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================