58 lines
1.9 KiB
Diff
58 lines
1.9 KiB
Diff
From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com>
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Date: Fri, 21 Feb 2020 12:06:56 +0100
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Subject: vhost: Check docket sk_family instead of call getname
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MIME-Version: 1.0
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Content-Type: text/plain; charset=UTF-8
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Content-Transfer-Encoding: 8bit
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Origin: https://git.kernel.org/linus/42d84c8490f9f0931786f1623191fcab397c3d64
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Bug-Debian-Security: https://security-tracker.debian.org/tracker/CVE-2020-10942
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Doing so, we save one call to get data we already have in the struct.
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Also, since there is no guarantee that getname use sockaddr_ll
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parameter beyond its size, we add a little bit of security here.
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It should do not do beyond MAX_ADDR_LEN, but syzbot found that
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ax25_getname writes more (72 bytes, the size of full_sockaddr_ax25,
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versus 20 + 32 bytes of sockaddr_ll + MAX_ADDR_LEN in syzbot repro).
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Fixes: 3a4d5c94e9593 ("vhost_net: a kernel-level virtio server")
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Reported-by: syzbot+f2a62d07a5198c819c7b@syzkaller.appspotmail.com
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Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
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Acked-by: Michael S. Tsirkin <mst@redhat.com>
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Signed-off-by: David S. Miller <davem@davemloft.net>
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---
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drivers/vhost/net.c | 10 +---------
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1 file changed, 1 insertion(+), 9 deletions(-)
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diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c
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index e158159671fa..18e205eeb9af 100644
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--- a/drivers/vhost/net.c
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+++ b/drivers/vhost/net.c
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@@ -1414,10 +1414,6 @@ static int vhost_net_release(struct inode *inode, struct file *f)
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static struct socket *get_raw_socket(int fd)
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{
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- struct {
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- struct sockaddr_ll sa;
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- char buf[MAX_ADDR_LEN];
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- } uaddr;
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int r;
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struct socket *sock = sockfd_lookup(fd, &r);
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@@ -1430,11 +1426,7 @@ static struct socket *get_raw_socket(int fd)
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goto err;
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}
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- r = sock->ops->getname(sock, (struct sockaddr *)&uaddr.sa, 0);
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- if (r < 0)
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- goto err;
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-
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- if (uaddr.sa.sll_family != AF_PACKET) {
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+ if (sock->sk->sk_family != AF_PACKET) {
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r = -EPFNOSUPPORT;
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goto err;
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}
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--
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2.26.2
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