==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:345 [inline]
BUG: KASAN: slab-out-of-bounds in skb_copy_from_linear_data include/linux/skbuff.h:3416 [inline]
BUG: KASAN: slab-out-of-bounds in __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395
Read of size 4294967282 at addr ffff8801c40e889c by task syz-executor5/12302

CPU: 0 PID: 12302 Comm: syz-executor5 Not tainted 4.19.0-rc7+ #122
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267
 memcpy+0x23/0x50 mm/kasan/kasan.c:302
 memcpy include/linux/string.h:345 [inline]
 skb_copy_from_linear_data include/linux/skbuff.h:3416 [inline]
 __pskb_copy_fclone+0x2dd/0xeb0 net/core/skbuff.c:1395
 __pskb_copy include/linux/skbuff.h:1053 [inline]
 pskb_copy include/linux/skbuff.h:2899 [inline]
 skb_realloc_headroom+0xe7/0x120 net/core/skbuff.c:1539
 ipip6_tunnel_xmit net/ipv6/sit.c:965 [inline]
 sit_tunnel_xmit+0xe1b/0x30d0 net/ipv6/sit.c:1029
 __netdev_start_xmit include/linux/netdevice.h:4336 [inline]
 netdev_start_xmit include/linux/netdevice.h:4345 [inline]
 xmit_one net/core/dev.c:3252 [inline]
 dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3268
 __dev_queue_xmit+0x2f0d/0x3950 net/core/dev.c:3838
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3871
 __bpf_tx_skb net/core/filter.c:2017 [inline]
 __bpf_redirect_common net/core/filter.c:2055 [inline]
 __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2062
 ____bpf_clone_redirect net/core/filter.c:2095 [inline]
 bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2067
 bpf_prog_41f2bcae09cd4ac3+0x6ea/0x1000

Allocated by task 12302:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc_node mm/slab.c:3682 [inline]
 __kmalloc_node_track_caller+0x47/0x70 mm/slab.c:3696
 __kmalloc_reserve.isra.39+0x41/0xe0 net/core/skbuff.c:137
 pskb_expand_head+0x230/0x10f0 net/core/skbuff.c:1460
 skb_ensure_writable+0x3dd/0x640 net/core/skbuff.c:5070
 __bpf_try_make_writable net/core/filter.c:1638 [inline]
 bpf_try_make_writable net/core/filter.c:1644 [inline]
 bpf_try_make_head_writable net/core/filter.c:1652 [inline]
 ____bpf_clone_redirect net/core/filter.c:2089 [inline]
 bpf_clone_redirect+0x14a/0x490 net/core/filter.c:2067
 bpf_prog_41f2bcae09cd4ac3+0x6ea/0x1000

Freed by task 10580:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3813
 skb_free_head+0x99/0xc0 net/core/skbuff.c:550
 pskb_expand_head+0x3bb/0x10f0 net/core/skbuff.c:1493
 __skb_cow include/linux/skbuff.h:2940 [inline]
 skb_cow_head include/linux/skbuff.h:2974 [inline]
 ipgre_xmit+0x679/0xba0 net/ipv4/ip_gre.c:684
 __netdev_start_xmit include/linux/netdevice.h:4336 [inline]
 netdev_start_xmit include/linux/netdevice.h:4345 [inline]
 xmit_one net/core/dev.c:3252 [inline]
 dev_hard_start_xmit+0x295/0xc90 net/core/dev.c:3268
 __dev_queue_xmit+0x2f0d/0x3950 net/core/dev.c:3838
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3871
 __bpf_tx_skb net/core/filter.c:2017 [inline]
 __bpf_redirect_common net/core/filter.c:2055 [inline]
 __bpf_redirect+0x5cf/0xb20 net/core/filter.c:2062
 ____bpf_clone_redirect net/core/filter.c:2095 [inline]
 bpf_clone_redirect+0x2f6/0x490 net/core/filter.c:2067
 0xffffffffa0020b4c

The buggy address belongs to the object at ffff8801c40e8840
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 92 bytes inside of
 512-byte region [ffff8801c40e8840, ffff8801c40e8a40)
The buggy address belongs to the page:
page:ffffea0007103a00 count:1 mapcount:0 mapping:ffff8801da800940 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffffea000723cd48 ffffea0007604208 ffff8801da800940
raw: 0000000000000000 ffff8801c40e80c0 0000000100000006 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c40e8900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801c40e8980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801c40e8a00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                           ^
 ffff8801c40e8a80: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff8801c40e8b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================