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authorToshiaki Makita2018-04-17 18:46:14 +0900
committerDavid S. Miller2018-04-17 13:59:28 -0400
commit7ce2367254e84753bceb07327aaf5c953cfce117 (patch)
tree1d95ba3fc84c3328a5616275ddae6e8a4f0e3ccc /net/core
parent77ac725e0c5b27c925e514b999cd46d01eedafd1 (diff)
vlan: Fix reading memory beyond skb->tail in skb_vlan_tagged_multi
Syzkaller spotted an old bug which leads to reading skb beyond tail by 4 bytes on vlan tagged packets. This is caused because skb_vlan_tagged_multi() did not check skb_headlen. BUG: KMSAN: uninit-value in eth_type_vlan include/linux/if_vlan.h:283 [inline] BUG: KMSAN: uninit-value in skb_vlan_tagged_multi include/linux/if_vlan.h:656 [inline] BUG: KMSAN: uninit-value in vlan_features_check include/linux/if_vlan.h:672 [inline] BUG: KMSAN: uninit-value in dflt_features_check net/core/dev.c:2949 [inline] BUG: KMSAN: uninit-value in netif_skb_features+0xd1b/0xdc0 net/core/dev.c:3009 CPU: 1 PID: 3582 Comm: syzkaller435149 Not tainted 4.16.0+ #82 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 __msan_warning_32+0x6c/0xb0 mm/kmsan/kmsan_instr.c:676 eth_type_vlan include/linux/if_vlan.h:283 [inline] skb_vlan_tagged_multi include/linux/if_vlan.h:656 [inline] vlan_features_check include/linux/if_vlan.h:672 [inline] dflt_features_check net/core/dev.c:2949 [inline] netif_skb_features+0xd1b/0xdc0 net/core/dev.c:3009 validate_xmit_skb+0x89/0x1320 net/core/dev.c:3084 __dev_queue_xmit+0x1cb2/0x2b60 net/core/dev.c:3549 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3590 packet_snd net/packet/af_packet.c:2944 [inline] packet_sendmsg+0x7c57/0x8a10 net/packet/af_packet.c:2969 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] sock_write_iter+0x3b9/0x470 net/socket.c:909 do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776 do_iter_write+0x30d/0xd40 fs/read_write.c:932 vfs_writev fs/read_write.c:977 [inline] do_writev+0x3c9/0x830 fs/read_write.c:1012 SYSC_writev+0x9b/0xb0 fs/read_write.c:1085 SyS_writev+0x56/0x80 fs/read_write.c:1082 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x43ffa9 RSP: 002b:00007fff2cff3948 EFLAGS: 00000217 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 000000000043ffa9 RDX: 0000000000000001 RSI: 0000000020000080 RDI: 0000000000000003 RBP: 00000000006cb018 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000217 R12: 00000000004018d0 R13: 0000000000401960 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:278 [inline] kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:188 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:314 kmsan_slab_alloc+0x11/0x20 mm/kmsan/kmsan.c:321 slab_post_alloc_hook mm/slab.h:445 [inline] slab_alloc_node mm/slub.c:2737 [inline] __kmalloc_node_track_caller+0xaed/0x11c0 mm/slub.c:4369 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x2cf/0x9f0 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:984 [inline] alloc_skb_with_frags+0x1d4/0xb20 net/core/skbuff.c:5234 sock_alloc_send_pskb+0xb56/0x1190 net/core/sock.c:2085 packet_alloc_skb net/packet/af_packet.c:2803 [inline] packet_snd net/packet/af_packet.c:2894 [inline] packet_sendmsg+0x6444/0x8a10 net/packet/af_packet.c:2969 sock_sendmsg_nosec net/socket.c:630 [inline] sock_sendmsg net/socket.c:640 [inline] sock_write_iter+0x3b9/0x470 net/socket.c:909 do_iter_readv_writev+0x7bb/0x970 include/linux/fs.h:1776 do_iter_write+0x30d/0xd40 fs/read_write.c:932 vfs_writev fs/read_write.c:977 [inline] do_writev+0x3c9/0x830 fs/read_write.c:1012 SYSC_writev+0x9b/0xb0 fs/read_write.c:1085 SyS_writev+0x56/0x80 fs/read_write.c:1082 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Fixes: 58e998c6d239 ("offloading: Force software GSO for multiple vlan tags.") Reported-and-tested-by: syzbot+0bbe42c764feafa82c5a@syzkaller.appspotmail.com Signed-off-by: Toshiaki Makita <makita.toshiaki@lab.ntt.co.jp> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r--net/core/dev.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/core/dev.c b/net/core/dev.c
index 969462ebb296..af0558b00c6c 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -2969,7 +2969,7 @@ netdev_features_t passthru_features_check(struct sk_buff *skb,
}
EXPORT_SYMBOL(passthru_features_check);
-static netdev_features_t dflt_features_check(const struct sk_buff *skb,
+static netdev_features_t dflt_features_check(struct sk_buff *skb,
struct net_device *dev,
netdev_features_t features)
{