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| author | Peilin Ye <yepeilin.cs@gmail.com> | 2020-07-22 19:05:12 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-07-31 19:47:14 +0300 |
| commit | f7b38459759ea5ee971c8d09328c7e5d82cae69c (patch) | |
| tree | a7bbe0e1da0ea2027071d59d9c9014a7ff8ba639 | |
| parent | 350cffdc4131014aed64fdfcb5526e21ccfe9811 (diff) | |
| download | linux-f7b38459759ea5ee971c8d09328c7e5d82cae69c.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>
| -rw-r--r-- | net/ax25/af_ax25.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ax25/af_ax25.c b/net/ax25/af_ax25.c index ef5bf116157a..0862fe49d434 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; } |