From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit 6a341729fb31b4c5df9f74f24b4b1c98410c9b87 ]
syzkaller reported a warning below [0].
We can reproduce it by sending 0-byte data from the (AF_PACKET, SOCK_PACKET) socket via some devices whose dev->hard_header_len is 0.
struct sockaddr_pkt addr = { .spkt_family = AF_PACKET, .spkt_device = "tun0", }; int fd;
fd = socket(AF_PACKET, SOCK_PACKET, 0); sendto(fd, NULL, 0, 0, (struct sockaddr *)&addr, sizeof(addr));
We have a similar fix for the (AF_PACKET, SOCK_RAW) socket as commit dc633700f00f ("net/af_packet: check len when min_header_len equals to 0").
Let's add the same test for the SOCK_PACKET socket.
[0]: skb_assert_len WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 skb_assert_len include/linux/skbuff.h:2552 [inline] WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 __dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159 Modules linked in: CPU: 1 PID: 19945 Comm: syz-executor.0 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:skb_assert_len include/linux/skbuff.h:2552 [inline] RIP: 0010:__dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159 Code: 89 de e8 1d a2 85 fd 84 db 75 21 e8 64 a9 85 fd 48 c7 c6 80 2a 1f 86 48 c7 c7 c0 06 1f 86 c6 05 23 cf 27 04 01 e8 fa ee 56 fd <0f> 0b e8 43 a9 85 fd 0f b6 1d 0f cf 27 04 31 ff 89 de e8 e3 a1 85 RSP: 0018:ffff8880217af6e0 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90001133000 RDX: 0000000000040000 RSI: ffffffff81186922 RDI: 0000000000000001 RBP: ffff8880217af8b0 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: ffff888030045640 R13: ffff8880300456b0 R14: ffff888030045650 R15: ffff888030045718 FS: 00007fc5864da640(0000) GS:ffff88806cd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020005740 CR3: 000000003f856003 CR4: 0000000000770ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: <TASK> dev_queue_xmit include/linux/netdevice.h:3085 [inline] packet_sendmsg_spkt+0xc4b/0x1230 net/packet/af_packet.c:2066 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0x1b4/0x200 net/socket.c:747 ____sys_sendmsg+0x331/0x970 net/socket.c:2503 ___sys_sendmsg+0x11d/0x1c0 net/socket.c:2557 __sys_sendmmsg+0x18c/0x430 net/socket.c:2643 __do_sys_sendmmsg net/socket.c:2672 [inline] __se_sys_sendmmsg net/socket.c:2669 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3c/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7fc58791de5d Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48 RSP: 002b:00007fc5864d9cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007fc58791de5d RDX: 0000000000000001 RSI: 0000000020005740 RDI: 0000000000000004 RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007fc58797e530 R15: 0000000000000000 </TASK> ---[ end trace 0000000000000000 ]--- skb len=0 headroom=16 headlen=0 tailroom=304 mac=(16,0) net=(16,-1) trans=-1 shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0)) csum(0x0 ip_summed=0 complete_sw=0 valid=0 level=0) hash(0x0 sw=0 l4=0) proto=0x0000 pkttype=0 iif=0 dev name=sit0 feat=0x00000006401d7869 sk family=17 type=10 proto=0
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: Kuniyuki Iwashima kuniyu@amazon.com Reviewed-by: Willem de Bruijn willemb@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/packet/af_packet.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index ac9335d76fb73..2af2ab924d64a 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2035,7 +2035,7 @@ static int packet_sendmsg_spkt(struct socket *sock, struct msghdr *msg, goto retry; }
- if (!dev_validate_header(dev, skb->data, len)) { + if (!dev_validate_header(dev, skb->data, len) || !skb->len) { err = -EINVAL; goto out_unlock; }