device syz7 entered promiscuous mode ================================================================== BUG: KASAN: use-after-free in __tcp_hdrlen include/linux/tcp.h:35 [inline] BUG: KASAN: use-after-free in tcp_hdrlen include/linux/tcp.h:40 [inline] BUG: KASAN: use-after-free in qdisc_pkt_len_init net/core/dev.c:3171 [inline] BUG: KASAN: use-after-free in __dev_queue_xmit+0x297c/0x2b50 net/core/dev.c:3477 Read of size 2 at addr ffff8801d6d05f38 by task syz-executor7/9908 CPU: 0 PID: 9908 Comm: syz-executor7 Not tainted 4.15.0-rc6-mm1+ #52 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_address_description+0x73/0x250 mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report+0x23b/0x360 mm/kasan/report.c:412 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:431 __tcp_hdrlen include/linux/tcp.h:35 [inline] tcp_hdrlen include/linux/tcp.h:40 [inline] qdisc_pkt_len_init net/core/dev.c:3171 [inline] __dev_queue_xmit+0x297c/0x2b50 net/core/dev.c:3477 dev_queue_xmit+0x17/0x20 net/core/dev.c:3566 packet_snd net/packet/af_packet.c:2944 [inline] packet_sendmsg+0x3aed/0x60b0 net/packet/af_packet.c:2969 sock_sendmsg_nosec net/socket.c:628 [inline] sock_sendmsg+0xca/0x110 net/socket.c:638 sock_write_iter+0x31a/0x5d0 net/socket.c:907 call_write_iter include/linux/fs.h:1775 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x684/0x970 fs/read_write.c:482 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 entry_SYSCALL_64_fastpath+0x23/0x9a RIP: 0033:0x452ac9 RSP: 002b:00007f3e6b199c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9 RDX: 000000000000014b RSI: 000000002040c000 RDI: 0000000000000015 RBP: 000000000000005c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006ee940 R13: 00000000ffffffff R14: 00007f3e6b19a6d4 R15: 0000000000000000 Allocated by task 6596: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552 __do_kmalloc_node mm/slab.c:3669 [inline] __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3683 __kmalloc_reserve.isra.39+0x41/0xd0 net/core/skbuff.c:137 __alloc_skb+0x13b/0x780 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:983 [inline] kobject_uevent_net_broadcast lib/kobject_uevent.c:319 [inline] kobject_uevent_env+0x83e/0xd30 lib/kobject_uevent.c:516 kvm_uevent_notify_change.part.39+0x394/0x430 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3890 kvm_uevent_notify_change arch/x86/kvm/../../../virt/kvm/kvm_main.c:3849 [inline] kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:709 [inline] kvm_put_kvm+0x181/0xde0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:750 kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:761 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ad0 kernel/exit.c:869 do_group_exit+0x149/0x400 kernel/exit.c:972 get_signal+0x73f/0x16c0 kernel/signal.c:2337 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809 exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264 entry_SYSCALL_64_fastpath+0x98/0x9a Freed by task 1775: save_stack+0x43/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527 __cache_free mm/slab.c:3485 [inline] kfree+0xd9/0x260 mm/slab.c:3800 skb_free_head+0x74/0xb0 net/core/skbuff.c:550 skb_release_data+0x58c/0x790 net/core/skbuff.c:570 skb_release_all+0x4a/0x60 net/core/skbuff.c:627 __kfree_skb net/core/skbuff.c:641 [inline] consume_skb+0x153/0x490 net/core/skbuff.c:701 skb_free_datagram+0x1a/0xe0 net/core/datagram.c:329 netlink_recvmsg+0x5cf/0x1300 net/netlink/af_netlink.c:1976 sock_recvmsg_nosec net/socket.c:801 [inline] sock_recvmsg+0xc9/0x110 net/socket.c:808 ___sys_recvmsg+0x2a4/0x640 net/socket.c:2177 __sys_recvmsg+0xe2/0x210 net/socket.c:2222 SYSC_recvmsg net/socket.c:2234 [inline] SyS_recvmsg+0x2d/0x50 net/socket.c:2229 entry_SYSCALL_64_fastpath+0x23/0x9a The buggy address belongs to the object at ffff8801d6d05b40 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 1016 bytes inside of 1024-byte region [ffff8801d6d05b40, ffff8801d6d05f40) The buggy address belongs to the page: page:ffffea00075b4100 count:1 mapcount:0 mapping:ffff8801d6d04040 index:0xffff8801d6d05b40 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801d6d04040 ffff8801d6d05b40 0000000100000004 raw: ffff8801dac01838 ffffea0006f24ba0 ffff8801dac00ac0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801d6d05e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801d6d05e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8801d6d05f00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8801d6d05f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8801d6d06000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================