kauditd_printk_skb: 147 callbacks suppressed audit: type=1400 audit(1549459623.590:4155): avc: denied { map } for pid=15953 comm="blkid" path="/lib/x86_64-linux-gnu/libblkid.so.1.1.0" dev="sda1" ino=2825 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 audit: type=1400 audit(1549459623.640:4156): avc: denied { map } for pid=15953 comm="blkid" path="/lib/x86_64-linux-gnu/libc-2.13.so" dev="sda1" ino=2784 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 ================================================================== BUG: KASAN: use-after-free in skb_clear_hash include/linux/skbuff.h:1128 [inline] BUG: KASAN: use-after-free in ip_check_defrag net/ipv4/ip_fragment.c:747 [inline] BUG: KASAN: use-after-free in ip_check_defrag+0x4f5/0x523 net/ipv4/ip_fragment.c:712 Write of size 4 at addr ffff8881ca564d1c by task syz-executor0/15944 CPU: 0 PID: 15944 Comm: syz-executor0 Not tainted 4.14.97+ #4 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xb9/0x10e lib/dump_stack.c:53 print_address_description+0x60/0x226 mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0x88/0x2a5 mm/kasan/report.c:393 audit: type=1400 audit(1549459623.640:4157): avc: denied { map } for pid=15953 comm="blkid" path="/lib/x86_64-linux-gnu/libc-2.13.so" dev="sda1" ino=2784 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Allocated by task 15944: audit: type=1400 audit(1549459623.720:4158): avc: denied { map } for pid=15957 comm="modprobe" path="/bin/kmod" dev="sda1" ino=1440 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.0+0x4f/0xd0 mm/kasan/kasan.c:551 slab_post_alloc_hook mm/slab.h:442 [inline] slab_alloc_node mm/slub.c:2723 [inline] slab_alloc mm/slub.c:2731 [inline] kmem_cache_alloc+0xd2/0x2d0 mm/slub.c:2736 skb_clone+0x126/0x310 net/core/skbuff.c:1278 skb_share_check include/linux/skbuff.h:1538 [inline] ip_check_defrag net/ipv4/ip_fragment.c:734 [inline] ip_check_defrag+0x2bc/0x523 net/ipv4/ip_fragment.c:712 packet_rcv_fanout+0x4d1/0x5e0 net/packet/af_packet.c:1463 deliver_skb net/core/dev.c:1881 [inline] dev_queue_xmit_nit+0x21a/0x960 net/core/dev.c:1937 Freed by task 15944: save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0xb0/0x190 mm/kasan/kasan.c:524 slab_free_hook mm/slub.c:1389 [inline] slab_free_freelist_hook mm/slub.c:1410 [inline] slab_free mm/slub.c:2966 [inline] kmem_cache_free+0xc4/0x330 mm/slub.c:2988 kfree_skbmem net/core/skbuff.c:582 [inline] kfree_skbmem+0xa0/0x100 net/core/skbuff.c:576 __kfree_skb net/core/skbuff.c:642 [inline] kfree_skb+0xcd/0x350 net/core/skbuff.c:659 ip_frag_queue net/ipv4/ip_fragment.c:507 [inline] ip_defrag+0x5f4/0x3b50 net/ipv4/ip_fragment.c:699 ip_check_defrag net/ipv4/ip_fragment.c:745 [inline] ip_check_defrag+0x39b/0x523 net/ipv4/ip_fragment.c:712 packet_rcv_fanout+0x4d1/0x5e0 net/packet/af_packet.c:1463 deliver_skb net/core/dev.c:1881 [inline] dev_queue_xmit_nit+0x21a/0x960 net/core/dev.c:1937 The buggy address belongs to the object at ffff8881ca564c80 which belongs to the cache skbuff_head_cache of size 224 The buggy address is located 156 bytes inside of 224-byte region [ffff8881ca564c80, ffff8881ca564d60) The buggy address belongs to the page: page:ffffea0007295900 count:1 mapcount:0 mapping: (null) index:0x0 flags: 0x4000000000000100(slab) raw: 4000000000000100 0000000000000000 0000000000000000 00000001800c000c raw: ffffea00075cfb80 0000000400000004 ffff8881dab58200 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881ca564c00: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ffff8881ca564c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb audit: type=1400 audit(1549459623.740:4159): avc: denied { create } for pid=15937 comm="syz-executor0" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=1 >ffff8881ca564d00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8881ca564d80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8881ca564e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================