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BUG: KASAN: slab-out-of-bounds in skb_headlen include/linux/skbuff.h:1898 [inline]
BUG: KASAN: slab-out-of-bounds in pskb_may_pull include/linux/skbuff.h:2112 [inline]
BUG: KASAN: slab-out-of-bounds in skb_ensure_writable+0x290/0x2e0 net/core/skbuff.c:5020
Read of size 4 at addr ffff8801c7809af8 by task syz-executor0/27957

CPU: 1 PID: 27957 Comm: syz-executor0 Not tainted 4.14.80+ #4
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x11b lib/dump_stack.c:53
 print_address_description+0x60/0x22b mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report.cold.6+0x11b/0x2dd mm/kasan/report.c:409
 skb_headlen include/linux/skbuff.h:1898 [inline]
 pskb_may_pull include/linux/skbuff.h:2112 [inline]
 skb_ensure_writable+0x290/0x2e0 net/core/skbuff.c:5020
 __bpf_try_make_writable net/core/filter.c:1403 [inline]
 bpf_try_make_writable net/core/filter.c:1409 [inline]
 ____bpf_l4_csum_replace net/core/filter.c:1578 [inline]
 bpf_l4_csum_replace+0x61/0x300 net/core/filter.c:1565
 ___bpf_prog_run+0x248e/0x5c70 kernel/bpf/core.c:1012

Allocated by task 26353:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc.part.1+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+0xe4/0x2b0 mm/slub.c:2736
 skb_clone+0x120/0x300 net/core/skbuff.c:1278
 skb_share_check include/linux/skbuff.h:1522 [inline]
 packet_rcv_spkt+0x3a2/0x4b0 net/packet/af_packet.c:1857
 deliver_skb net/core/dev.c:1881 [inline]
 deliver_ptype_list_skb net/core/dev.c:1896 [inline]
 __netif_receive_skb_core+0xa28/0x2d10 net/core/dev.c:4460
 __netif_receive_skb+0x58/0x1f0 net/core/dev.c:4515
 netif_receive_skb_internal+0xfc/0x5e0 net/core/dev.c:4588
 napi_skb_finish net/core/dev.c:4949 [inline]
 napi_gro_receive+0x20e/0x410 net/core/dev.c:4980
 receive_buf+0xa55/0x42c0 drivers/net/virtio_net.c:847
 virtnet_receive drivers/net/virtio_net.c:1093 [inline]
 virtnet_poll+0x2af/0x910 drivers/net/virtio_net.c:1174
 napi_poll net/core/dev.c:5591 [inline]
 net_rx_action+0x371/0xce0 net/core/dev.c:5657
 __do_softirq+0x20d/0x9bd kernel/softirq.c:288

Freed by task 26353:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xac/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+0x12d/0x350 mm/slub.c:2988
 kfree_skbmem+0x9e/0x100 net/core/skbuff.c:582
 __kfree_skb net/core/skbuff.c:642 [inline]
 kfree_skb+0xd0/0x340 net/core/skbuff.c:659
 packet_rcv_spkt+0xd5/0x4b0 net/packet/af_packet.c:1888
 deliver_skb net/core/dev.c:1881 [inline]
 deliver_ptype_list_skb net/core/dev.c:1896 [inline]
 __netif_receive_skb_core+0xa28/0x2d10 net/core/dev.c:4460
 __netif_receive_skb+0x58/0x1f0 net/core/dev.c:4515
 netif_receive_skb_internal+0xfc/0x5e0 net/core/dev.c:4588
 napi_skb_finish net/core/dev.c:4949 [inline]
 napi_gro_receive+0x20e/0x410 net/core/dev.c:4980
 receive_buf+0xa55/0x42c0 drivers/net/virtio_net.c:847
 virtnet_receive drivers/net/virtio_net.c:1093 [inline]
 virtnet_poll+0x2af/0x910 drivers/net/virtio_net.c:1174
 napi_poll net/core/dev.c:5591 [inline]
 net_rx_action+0x371/0xce0 net/core/dev.c:5657
 __do_softirq+0x20d/0x9bd kernel/softirq.c:288

The buggy address belongs to the object at ffff8801c7809a00
 which belongs to the cache skbuff_head_cache of size 224
The buggy address is located 24 bytes to the right of
 224-byte region [ffff8801c7809a00, ffff8801c7809ae0)
The buggy address belongs to the page:
page:ffffea00071e0240 count:1 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000100(slab)
raw: 4000000000000100 0000000000000000 0000000000000000 00000001800c000c
raw: 0000000000000000 0000000100000001 ffff8801dab70200 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c7809980: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801c7809a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801c7809a80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                                                                ^
 ffff8801c7809b00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
 ffff8801c7809b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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