================================================================== BUG: KASAN: use-after-free in eth_header_parse_protocol+0xad/0xd0 net/ethernet/eth.c:282 Read of size 2 at addr ffff8881e88f000b by task syz-executor293/338 CPU: 0 PID: 338 Comm: syz-executor293 Not tainted 5.4.106-syzkaller-00698-g3941336d0e38 #0 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+0x1d8/0x24e lib/dump_stack.c:118 print_address_description+0x9b/0x650 mm/kasan/report.c:384 __kasan_report+0x182/0x260 mm/kasan/report.c:516 kasan_report+0x30/0x60 mm/kasan/common.c:641 eth_header_parse_protocol+0xad/0xd0 net/ethernet/eth.c:282 dev_parse_header_protocol include/linux/netdevice.h:2984 [inline] virtio_net_hdr_to_skb+0x6de/0xd70 include/linux/virtio_net.h:83 packet_snd net/packet/af_packet.c:2976 [inline] packet_sendmsg+0x483a/0x6780 net/packet/af_packet.c:3013 sock_sendmsg_nosec net/socket.c:638 [inline] sock_sendmsg net/socket.c:658 [inline] sock_write_iter+0x330/0x450 net/socket.c:990 call_write_iter include/linux/fs.h:1971 [inline] new_sync_write fs/read_write.c:483 [inline] __vfs_write+0x5ec/0x780 fs/read_write.c:496 vfs_write+0x212/0x4e0 fs/read_write.c:558 ksys_write+0x186/0x2b0 fs/read_write.c:611 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x43ef39 Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd4a23ee78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000400488 RCX: 000000000043ef39 RDX: 000000000000fdef RSI: 0000000020000000 RDI: 0000000000000003 RBP: 0000000000402f20 R08: 0000000000400488 R09: 0000000000400488 R10: 0000000000400488 R11: 0000000000000246 R12: 0000000000402fb0 R13: 0000000000000000 R14: 00000000004ac018 R15: 0000000000400488 Allocated by task 338: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] __kasan_kmalloc+0x137/0x1e0 mm/kasan/common.c:517 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slub.c:2821 [inline] slab_alloc mm/slub.c:2829 [inline] kmem_cache_alloc+0x115/0x290 mm/slub.c:2834 getname_flags+0xba/0x640 fs/namei.c:141 user_path_at_empty+0x28/0x50 fs/namei.c:2683 user_path_at include/linux/namei.h:49 [inline] do_faccessat+0x323/0x7a0 fs/open.c:398 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Freed by task 338: save_stack mm/kasan/common.c:70 [inline] set_track mm/kasan/common.c:78 [inline] kasan_set_free_info mm/kasan/common.c:333 [inline] __kasan_slab_free+0x18a/0x240 mm/kasan/common.c:475 slab_free_hook mm/slub.c:1454 [inline] slab_free_freelist_hook+0x7b/0x150 mm/slub.c:1492 slab_free mm/slub.c:3072 [inline] kmem_cache_free+0xb8/0x5f0 mm/slub.c:3088 putname fs/namei.c:262 [inline] filename_lookup+0x4bb/0x6a0 fs/namei.c:2432 user_path_at include/linux/namei.h:49 [inline] do_faccessat+0x323/0x7a0 fs/open.c:398 do_syscall_64+0xcb/0x1e0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 The buggy address belongs to the object at ffff8881e88f0000 which belongs to the cache names_cache of size 4096 The buggy address is located 11 bytes inside of 4096-byte region [ffff8881e88f0000, ffff8881e88f1000) The buggy address belongs to the page: page:ffffea0007a23c00 refcount:1 mapcount:0 mapping:ffff8881f5cfb680 index:0x0 compound_mapcount: 0 flags: 0x8000000000010200(slab|head) raw: 8000000000010200 dead000000000100 dead000000000122 ffff8881f5cfb680 raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881e88eff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8881e88eff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8881e88f0000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881e88f0080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881e88f0100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb