================================================================== BUG: KASAN: use-after-free in __skb_flow_dissect+0x9bf/0x5920 net/core/flow_dissector.c:1090 Read of size 1 at addr ffff88816f4c000e by task syz-executor323/3630 CPU: 0 PID: 3630 Comm: syz-executor323 Not tainted 6.0.0-rc6-next-20220923-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x15e/0x45d mm/kasan/report.c:395 kasan_report+0xbb/0x1f0 mm/kasan/report.c:495 __skb_flow_dissect+0x9bf/0x5920 net/core/flow_dissector.c:1090 skb_flow_dissect_flow_keys include/linux/skbuff.h:1486 [inline] ___skb_get_hash net/core/flow_dissector.c:1698 [inline] __skb_get_hash+0xb6/0x4b0 net/core/flow_dissector.c:1764 skb_get_hash include/linux/skbuff.h:1528 [inline] ip_tunnel_xmit+0x18f0/0x3170 net/ipv4/ip_tunnel.c:730 ipip_tunnel_xmit+0x413/0x510 net/ipv4/ipip.c:307 __netdev_start_xmit include/linux/netdevice.h:4839 [inline] netdev_start_xmit include/linux/netdevice.h:4853 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x1be/0x990 net/core/dev.c:3606 __dev_queue_xmit+0x2c9a/0x3b60 net/core/dev.c:4256 dev_queue_xmit include/linux/netdevice.h:3008 [inline] neigh_connected_output+0x3c0/0x520 net/core/neighbour.c:1581 neigh_output include/net/neighbour.h:551 [inline] ip_finish_output2+0x782/0x2170 net/ipv4/ip_output.c:228 __ip_finish_output net/ipv4/ip_output.c:306 [inline] __ip_finish_output+0x396/0x650 net/ipv4/ip_output.c:288 ip_finish_output+0x2d/0x280 net/ipv4/ip_output.c:316 NF_HOOK_COND include/linux/netfilter.h:291 [inline] ip_mc_output+0x21b/0x700 net/ipv4/ip_output.c:415 dst_output include/net/dst.h:451 [inline] ip_local_out+0xaf/0x1a0 net/ipv4/ip_output.c:126 iptunnel_xmit+0x67a/0x9e0 net/ipv4/ip_tunnel_core.c:82 ip_tunnel_xmit+0x143f/0x3170 net/ipv4/ip_tunnel.c:813 ipgre_xmit+0x6e0/0x900 net/ipv4/ip_gre.c:661 __netdev_start_xmit include/linux/netdevice.h:4839 [inline] netdev_start_xmit include/linux/netdevice.h:4853 [inline] xmit_one net/core/dev.c:3590 [inline] dev_hard_start_xmit+0x1be/0x990 net/core/dev.c:3606 __dev_queue_xmit+0x2c9a/0x3b60 net/core/dev.c:4256 dev_queue_xmit include/linux/netdevice.h:3008 [inline] __bpf_tx_skb net/core/filter.c:2116 [inline] __bpf_redirect_no_mac net/core/filter.c:2141 [inline] __bpf_redirect+0x666/0xe40 net/core/filter.c:2164 ____bpf_clone_redirect net/core/filter.c:2431 [inline] bpf_clone_redirect+0x2ae/0x420 net/core/filter.c:2403 bpf_prog_801cabf80fc815cd+0x59/0x5e bpf_dispatcher_nop_func include/linux/bpf.h:958 [inline] __bpf_prog_run include/linux/filter.h:600 [inline] bpf_prog_run include/linux/filter.h:607 [inline] bpf_test_run+0x381/0x9d0 net/bpf/test_run.c:402 bpf_prog_test_run_skb+0xbab/0x1e60 net/bpf/test_run.c:1182 bpf_prog_test_run kernel/bpf/syscall.c:3630 [inline] __sys_bpf+0x10a0/0x4cf0 kernel/bpf/syscall.c:4983 __do_sys_bpf kernel/bpf/syscall.c:5069 [inline] __se_sys_bpf kernel/bpf/syscall.c:5067 [inline] __x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:5067 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f4216122e69 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fff879260a8 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f4216122e69 RDX: 0000000000000028 RSI: 0000000020000080 RDI: 000000000000000a RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d R10: 000000000000000d R11: 0000000000000246 R12: 00007fff879260c0 R13: 00000000000f4240 R14: 000000000000a815 R15: 00007fff879260b4 </TASK> The buggy address belongs to the physical page: page:ffffea0005bd3000 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x16f4c0 flags: 0x57ff00000000000(node=1|zone=2|lastcpupid=0x7ff) raw: 057ff00000000000 ffffea0005bd3008 ffffea0005bd3008 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner info is not present (never set?) Memory state around the buggy address: ffff88816f4bff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88816f4bff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88816f4c0000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88816f4c0080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88816f4c0100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ==================================================================