From: Peilin Ye yepeilin.cs@gmail.com
[ 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 --- net/ax25/af_ax25.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/ax25/af_ax25.c +++ b/net/ax25/af_ax25.c @@ -1512,7 +1512,8 @@ static int ax25_sendmsg(struct socket *s 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; }