diff options
| author | Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> | 2018-01-08 19:02:28 -0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-03-03 10:24:37 +0100 |
| commit | 413e58ac3d845144f9b70b85b2f4add7d3249948 (patch) | |
| tree | 6f737078488878c6a541d7fc12261bc88c6f6388 /net/sctp | |
| parent | cd659881219d8a39a523d2a42ae04e3fc416d030 (diff) | |
sctp: add a ceiling to optlen in some sockopts
[ Upstream commit 5960cefab9df76600a1a7d4ff592c59e14616e88 ]
Hangbin Liu reported that some sockopt calls could cause the kernel to log
a warning on memory allocation failure if the user supplied a large optlen
value. That is because some of them called memdup_user() without a ceiling
on optlen, allowing it to try to allocate really large buffers.
This patch adds a ceiling by limiting optlen to the maximum allowed that
would still make sense for these sockopt.
Reported-by: Hangbin Liu <haliu@redhat.com>
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/sctp')
| -rw-r--r-- | net/sctp/socket.c | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/net/sctp/socket.c b/net/sctp/socket.c index 3c8b92667866..8d117cb65294 100644 --- a/net/sctp/socket.c +++ b/net/sctp/socket.c @@ -3494,6 +3494,8 @@ static int sctp_setsockopt_hmac_ident(struct sock *sk, if (optlen < sizeof(struct sctp_hmacalgo)) return -EINVAL; + optlen = min_t(unsigned int, optlen, sizeof(struct sctp_hmacalgo) + + SCTP_AUTH_NUM_HMACS * sizeof(u16)); hmacs = memdup_user(optval, optlen); if (IS_ERR(hmacs)) @@ -3532,6 +3534,11 @@ static int sctp_setsockopt_auth_key(struct sock *sk, if (optlen <= sizeof(struct sctp_authkey)) return -EINVAL; + /* authkey->sca_keylength is u16, so optlen can't be bigger than + * this. + */ + optlen = min_t(unsigned int, optlen, USHRT_MAX + + sizeof(struct sctp_authkey)); authkey = memdup_user(optval, optlen); if (IS_ERR(authkey)) @@ -3889,6 +3896,9 @@ static int sctp_setsockopt_reset_streams(struct sock *sk, if (optlen < sizeof(*params)) return -EINVAL; + /* srs_number_streams is u16, so optlen can't be bigger than this. */ + optlen = min_t(unsigned int, optlen, USHRT_MAX + + sizeof(__u16) * sizeof(*params)); params = memdup_user(optval, optlen); if (IS_ERR(params)) |