================================================================== BUG: KASAN: use-after-free in rawv6_send_hdrinc net/ipv6/raw.c:683 [inline] BUG: KASAN: use-after-free in rawv6_sendmsg+0x2691/0x2820 net/ipv6/raw.c:916 Read of size 8 at addr ffff8801c5e37f18 by task syz-executor7/6310 CPU: 0 PID: 6310 Comm: syz-executor7 Not tainted 4.9.124-g09eb2ba #31 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801a02e76e0 ffffffff81eb95e9 ffffea0007178d80 ffff8801c5e37f18 0000000000000000 ffff8801c5e37f18 ffff8801c5e37f18 ffff8801a02e7718 ffffffff8156c35e ffff8801c5e37f18 0000000000000008 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] rawv6_send_hdrinc net/ipv6/raw.c:683 [inline] [] rawv6_sendmsg+0x2691/0x2820 net/ipv6/raw.c:916 [] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770 [] sock_sendmsg_nosec net/socket.c:648 [inline] [] sock_sendmsg+0xcc/0x110 net/socket.c:658 [] sock_write_iter+0x223/0x3b0 net/socket.c:856 [] new_sync_write fs/read_write.c:496 [inline] [] __vfs_write+0x3e0/0x580 fs/read_write.c:509 [] vfs_write+0x187/0x530 fs/read_write.c:557 [] SYSC_write fs/read_write.c:604 [inline] [] SyS_write+0xd9/0x1c0 fs/read_write.c:596 [] do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Allocated by task 6310: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:609 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547 slab_post_alloc_hook mm/slab.h:417 [inline] slab_alloc_node mm/slub.c:2715 [inline] slab_alloc mm/slub.c:2723 [inline] kmem_cache_alloc+0xbe/0x290 mm/slub.c:2728 dst_alloc+0xb5/0x1a0 net/core/dst.c:210 __ip6_dst_alloc+0x31/0x130 net/ipv6/route.c:334 ip6_rt_cache_alloc.isra.49+0xe0/0x440 net/ipv6/route.c:956 ip6_pol_route+0x126d/0x1d30 net/ipv6/route.c:1109 ip6_pol_route_output+0x4c/0x60 net/ipv6/route.c:1193 fib6_rule_action+0x23f/0x6b0 net/ipv6/fib6_rules.c:89 fib_rules_lookup+0x2aa/0x8b0 net/core/fib_rules.c:265 fib6_rule_lookup+0xe8/0x1a0 net/ipv6/fib6_rules.c:43 ip6_route_output_flags+0x24b/0x2b0 net/ipv6/route.c:1221 ip6_dst_lookup_tail+0x3df/0x16c0 net/ipv6/ip6_output.c:991 ip6_dst_lookup_flow+0xaa/0x210 net/ipv6/ip6_output.c:1092 rawv6_sendmsg+0x9b5/0x2820 net/ipv6/raw.c:900 inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:770 sock_sendmsg_nosec net/socket.c:648 [inline] sock_sendmsg+0xcc/0x110 net/socket.c:658 sock_write_iter+0x223/0x3b0 net/socket.c:856 new_sync_write fs/read_write.c:496 [inline] __vfs_write+0x3e0/0x580 fs/read_write.c:509 vfs_write+0x187/0x530 fs/read_write.c:557 SYSC_write fs/read_write.c:604 [inline] SyS_write+0xd9/0x1c0 fs/read_write.c:596 do_syscall_64+0x1a6/0x490 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb Freed by task 3: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack+0x43/0xd0 mm/kasan/kasan.c:505 set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:582 slab_free_hook mm/slub.c:1355 [inline] slab_free_freelist_hook mm/slub.c:1377 [inline] slab_free mm/slub.c:2958 [inline] kmem_cache_free+0xbe/0x310 mm/slub.c:2980 dst_destroy+0x200/0x360 net/core/dst.c:270 dst_destroy_rcu+0x15/0x40 net/core/dst.c:295 __rcu_reclaim kernel/rcu/rcu.h:118 [inline] rcu_do_batch kernel/rcu/tree.c:2789 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:3053 [inline] __rcu_process_callbacks kernel/rcu/tree.c:3020 [inline] rcu_process_callbacks+0x8ae/0x12b0 kernel/rcu/tree.c:3037 __do_softirq+0x210/0x940 kernel/softirq.c:288 The buggy address belongs to the object at ffff8801c5e37dc0 which belongs to the cache ip6_dst_cache of size 384 The buggy address is located 344 bytes inside of 384-byte region [ffff8801c5e37dc0, ffff8801c5e37f40) The buggy address belongs to the page: page:ffffea0007178d80 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x8000000000004080(slab|head) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c5e37e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c5e37e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801c5e37f00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8801c5e37f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801c5e38000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================