================================================================== BUG: KASAN: use-after-free in eth_header_parse_protocol+0xdc/0xe0 net/ethernet/eth.c:283 Read of size 2 at addr ffff888022a1600b by task syz-executor.2/25785 CPU: 1 PID: 25785 Comm: syz-executor.2 Not tainted 5.12.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 eth_header_parse_protocol+0xdc/0xe0 net/ethernet/eth.c:283 dev_parse_header_protocol include/linux/netdevice.h:3264 [inline] virtio_net_hdr_to_skb.constprop.0+0x99d/0xcd0 include/linux/virtio_net.h:83 packet_snd net/packet/af_packet.c:2994 [inline] packet_sendmsg+0x233c/0x5300 net/packet/af_packet.c:3031 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:674 sock_write_iter+0x289/0x3c0 net/socket.c:1001 call_write_iter include/linux/fs.h:1977 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x796/0xa30 fs/read_write.c:605 ksys_write+0x1ee/0x250 fs/read_write.c:658 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x466459 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0105695188 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000056bf60 RCX: 0000000000466459 RDX: 000000000000004c RSI: 0000000020000100 RDI: 0000000000000003 RBP: 00000000004bf9fb R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf60 R13: 00007fff56b43d0f R14: 00007f0105695300 R15: 0000000000022000 Allocated by task 4834: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:427 [inline] ____kasan_kmalloc mm/kasan/common.c:506 [inline] ____kasan_kmalloc mm/kasan/common.c:465 [inline] __kasan_kmalloc+0x99/0xc0 mm/kasan/common.c:515 kmalloc include/linux/slab.h:554 [inline] kzalloc include/linux/slab.h:684 [inline] kernfs_iop_get_link fs/kernfs/symlink.c:135 [inline] kernfs_iop_get_link+0x61/0x6e0 fs/kernfs/symlink.c:126 vfs_readlink+0x1d7/0x390 fs/namei.c:4806 do_readlinkat+0x27e/0x2f0 fs/stat.c:429 __do_sys_readlinkat fs/stat.c:444 [inline] __se_sys_readlinkat fs/stat.c:441 [inline] __x64_sys_readlinkat+0x93/0xf0 fs/stat.c:441 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 4834: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 ____kasan_slab_free mm/kasan/common.c:360 [inline] ____kasan_slab_free mm/kasan/common.c:325 [inline] __kasan_slab_free+0xf5/0x130 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:199 [inline] slab_free_hook mm/slub.c:1562 [inline] slab_free_freelist_hook+0x92/0x210 mm/slub.c:1600 slab_free mm/slub.c:3161 [inline] kfree+0xe5/0x7f0 mm/slub.c:4213 do_delayed_call include/linux/delayed_call.h:28 [inline] vfs_readlink+0x142/0x390 fs/namei.c:4811 do_readlinkat+0x27e/0x2f0 fs/stat.c:429 __do_sys_readlinkat fs/stat.c:444 [inline] __se_sys_readlinkat fs/stat.c:441 [inline] __x64_sys_readlinkat+0x93/0xf0 fs/stat.c:441 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Last potentially related work creation: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_record_aux_stack+0xe5/0x110 mm/kasan/generic.c:345 kvfree_call_rcu+0x10e/0x7d0 kernel/rcu/tree.c:3577 sctp_association_destroy net/sctp/associola.c:419 [inline] sctp_association_put+0x233/0x340 net/sctp/associola.c:866 sctp_transport_destroy net/sctp/transport.c:165 [inline] sctp_transport_put+0x105/0x180 net/sctp/transport.c:326 sctp_backlog_rcv+0x2a0/0x5c0 net/sctp/input.c:351 sk_backlog_rcv include/net/sock.h:1016 [inline] __release_sock+0x134/0x3b0 net/core/sock.c:2556 release_sock+0x54/0x1b0 net/core/sock.c:3080 sctp_sendmsg+0x105e/0x1d30 net/sctp/socket.c:2018 inet_sendmsg+0x99/0xe0 net/ipv4/af_inet.c:821 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:674 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2350 ___sys_sendmsg+0xf3/0x170 net/socket.c:2404 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2433 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888022a16000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 11 bytes inside of 4096-byte region [ffff888022a16000, ffff888022a17000) The buggy address belongs to the page: page:ffffea00008a8400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x22a10 head:ffffea00008a8400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0xfff00000010200(slab|head) raw: 00fff00000010200 0000000000000000 0000000100000001 ffff888010842140 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888022a15f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888022a15f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888022a16000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888022a16080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888022a16100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================