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authorPeilin Ye <yepeilin.cs@gmail.com>2020-07-22 19:05:12 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-07-31 19:39:29 +0300
commit52aeeec1a6359a9bb885a3bd9a1ad740873bf0bf (patch)
tree65f3170d2fc062c28e0ba2ae53b524302f12491b /net
parent2f1624faf647dfc96bf20b7fd94bdd46902d82fd (diff)
downloadlinux-52aeeec1a6359a9bb885a3bd9a1ad740873bf0bf.tar.xz
AX.25: Prevent out-of-bounds read in ax25_sendmsg()
[ Upstream commit 8885bb0621f01a6c82be60a91e5fc0f6e2f71186 ] Checks on `addr_len` and `usax->sax25_ndigis` are insufficient. ax25_sendmsg() can go out of bounds when `usax->sax25_ndigis` equals to 7 or 8. Fix it. It is safe to remove `usax->sax25_ndigis > AX25_MAX_DIGIS`, since `addr_len` is guaranteed to be less than or equal to `sizeof(struct full_sockaddr_ax25)` Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net')
-rw-r--r--net/ax25/af_ax25.c3
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c
index 085a6631eb22..dbe7ef2c7e75 100644
--- a/net/ax25/af_ax25.c
+++ b/net/ax25/af_ax25.c
@@ -1509,7 +1509,8 @@ static int ax25_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
struct full_sockaddr_ax25 *fsa = (struct full_sockaddr_ax25 *)usax;
/* Valid number of digipeaters ? */
- if (usax->sax25_ndigis < 1 || usax->sax25_ndigis > AX25_MAX_DIGIS) {
+ if (usax->sax25_ndigis < 1 || addr_len < sizeof(struct sockaddr_ax25) +
+ sizeof(ax25_address) * usax->sax25_ndigis) {
err = -EINVAL;
goto out;
}