audit: type=1400 audit(1514760184.557:7): avc: denied { map } for pid=3492 comm="syzkaller233465" path="/root/syzkaller233465124" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 device syz0 entered promiscuous mode ================================================================== BUG: KASAN: slab-out-of-bounds in __tcp_hdrlen include/linux/tcp.h:35 [inline] BUG: KASAN: slab-out-of-bounds in tcp_hdrlen include/linux/tcp.h:40 [inline] BUG: KASAN: slab-out-of-bounds in qdisc_pkt_len_init net/core/dev.c:3143 [inline] BUG: KASAN: slab-out-of-bounds in __dev_queue_xmit+0x27c8/0x2920 net/core/dev.c:3432 Read of size 2 at addr ffff8801c00a8920 by task syzkaller233465/3492 CPU: 1 PID: 3492 Comm: syzkaller233465 Not tainted 4.15.0-rc5+ #244 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:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report+0x25b/0x340 mm/kasan/report.c:409 __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:428 __tcp_hdrlen include/linux/tcp.h:35 [inline] tcp_hdrlen include/linux/tcp.h:40 [inline] qdisc_pkt_len_init net/core/dev.c:3143 [inline] __dev_queue_xmit+0x27c8/0x2920 net/core/dev.c:3432 dev_queue_xmit+0x17/0x20 net/core/dev.c:3521 packet_snd net/packet/af_packet.c:2943 [inline] packet_sendmsg+0x3aed/0x60b0 net/packet/af_packet.c:2968 sock_sendmsg_nosec net/socket.c:636 [inline] sock_sendmsg+0xca/0x110 net/socket.c:646 sock_write_iter+0x31a/0x5d0 net/socket.c:915 call_write_iter include/linux/fs.h:1772 [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: 0033:0x444449 RSP: 002b:00007fffd57dd798 EFLAGS: 00000297 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444449 RDX: 00000000000000ce RSI: 0000000020fecf2b RDI: 0000000000000005 RBP: 00000000006cf018 R08: 0000000000402130 R09: 0000000000402130 R10: 0000000000402130 R11: 0000000000000297 R12: 0000000000402130 R13: 00000000004021c0 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 3492: 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:551 __do_kmalloc_node mm/slab.c:3672 [inline] __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3686 __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] alloc_skb_with_frags+0x10d/0x750 net/core/skbuff.c:5147 sock_alloc_send_pskb+0x787/0x9b0 net/core/sock.c:2078 packet_alloc_skb net/packet/af_packet.c:2802 [inline] packet_snd net/packet/af_packet.c:2893 [inline] packet_sendmsg+0x1ece/0x60b0 net/packet/af_packet.c:2968 sock_sendmsg_nosec net/socket.c:636 [inline] sock_sendmsg+0xca/0x110 net/socket.c:646 sock_write_iter+0x31a/0x5d0 net/socket.c:915 call_write_iter include/linux/fs.h:1772 [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 Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8801c00a84c0 which belongs to the cache kmalloc-1024 of size 1024 The buggy address is located 96 bytes to the right of 1024-byte region [ffff8801c00a84c0, ffff8801c00a88c0) The buggy address belongs to the page: page:00000000f9d8af66 count:1 mapcount:0 mapping:00000000603a6de8 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000008100(slab|head) raw: 02fffc0000008100 ffff8801c00a8040 0000000000000000 0000000100000007 raw: ffffea0007019d20 ffff8801dac01848 ffff8801dac00ac0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c00a8800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801c00a8880: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff8801c00a8900: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00 ^ ffff8801c00a8980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8801c00a8a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================