================================================================== BUG: KASAN: use-after-free in rawv6_send_hdrinc net/ipv6/raw.c:692 [inline] BUG: KASAN: use-after-free in rawv6_sendmsg+0x4312/0x4630 net/ipv6/raw.c:921 Read of size 8 at addr ffff8801bce2cb70 by task syz-executor3/15657 CPU: 0 PID: 15657 Comm: syz-executor3 Not tainted 4.19.0-rc5-next-20180928+ #84 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d3/0x2c4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 rawv6_send_hdrinc net/ipv6/raw.c:692 [inline] rawv6_sendmsg+0x4312/0x4630 net/ipv6/raw.c:921 inet_sendmsg+0x19c/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 sock_write_iter+0x35e/0x5c0 net/socket.c:901 call_write_iter include/linux/fs.h:1825 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fdccd221c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579 RDX: 0000000000000030 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdccd2226d4 R13: 00000000004c2897 R14: 00000000004d8568 R15: 00000000ffffffff Allocated by task 15657: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554 dst_alloc+0xbb/0x1d0 net/core/dst.c:105 ip6_dst_alloc+0x35/0xa0 net/ipv6/route.c:353 ip6_rt_cache_alloc+0x247/0x7b0 net/ipv6/route.c:1190 ip6_pol_route+0x8f8/0xd90 net/ipv6/route.c:1875 ip6_pol_route_output+0x54/0x70 net/ipv6/route.c:2073 fib6_rule_lookup+0x277/0x860 net/ipv6/fib6_rules.c:122 ip6_route_output_flags+0x2c5/0x350 net/ipv6/route.c:2102 ip6_dst_lookup_tail+0x125c/0x1d60 net/ipv6/ip6_output.c:976 ip6_dst_lookup_flow+0xc8/0x270 net/ipv6/ip6_output.c:1077 rawv6_sendmsg+0x12d9/0x4630 net/ipv6/raw.c:905 inet_sendmsg+0x19c/0x690 net/ipv4/af_inet.c:798 sock_sendmsg_nosec net/socket.c:622 [inline] sock_sendmsg+0xd5/0x120 net/socket.c:632 sock_write_iter+0x35e/0x5c0 net/socket.c:901 call_write_iter include/linux/fs.h:1825 [inline] new_sync_write fs/read_write.c:474 [inline] __vfs_write+0x6b8/0x9f0 fs/read_write.c:487 vfs_write+0x1fc/0x560 fs/read_write.c:549 ksys_write+0x101/0x260 fs/read_write.c:598 __do_sys_write fs/read_write.c:610 [inline] __se_sys_write fs/read_write.c:607 [inline] __x64_sys_write+0x73/0xb0 fs/read_write.c:607 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 15666: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3756 dst_destroy+0x267/0x3c0 net/core/dst.c:141 dst_destroy_rcu+0x16/0x19 net/core/dst.c:154 __rcu_reclaim kernel/rcu/rcu.h:240 [inline] rcu_do_batch kernel/rcu/tree.c:2437 [inline] invoke_rcu_callbacks kernel/rcu/tree.c:2716 [inline] rcu_process_callbacks+0xff9/0x1ad0 kernel/rcu/tree.c:2697 __do_softirq+0x30b/0xb03 kernel/softirq.c:292 The buggy address belongs to the object at ffff8801bce2cac0 which belongs to the cache ip6_dst_cache of size 224 The buggy address is located 176 bytes inside of 224-byte region [ffff8801bce2cac0, ffff8801bce2cba0) The buggy address belongs to the page: page:ffffea0006f38b00 count:1 mapcount:0 mapping:ffff8801caf51780 index:0xffff8801bce2cd40 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea0006fe5848 ffffea0006fbfd88 ffff8801caf51780 raw: ffff8801bce2cd40 ffff8801bce2c0c0 0000000100000007 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801bce2ca00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff8801bce2ca80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb >ffff8801bce2cb00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801bce2cb80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ffff8801bce2cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================