On 03/07/2018 09:09 AM, Steve Dickson wrote:
> Commit 2936f109590e add free()s on memory that
> was allocated from the stack (via alloca()).
> That type memory is automatically freed so
> those added free()s was causing a double frees.
>
> It was suggested allocating memory from the
> stack can be a bit troublesome. So this patch
> changes the memory allocation from the stack
> to the heap which also eliminates the double frees.
>
> Fixes: 2936f109590e ("clnt_dg_call: Fix a buffer overflow (CVE-2016-4429)")
> BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1552163
>
> Signed-off-by: Steve Dickson <steved@xxxxxxxxxx>
Committed...
steved.
> ---
> src/clnt_dg.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/src/clnt_dg.c b/src/clnt_dg.c
> index 884a2db..04a2aba 100644
> --- a/src/clnt_dg.c
> +++ b/src/clnt_dg.c
> @@ -430,7 +430,7 @@ get_reply:
> struct sockaddr_in err_addr;
> struct sockaddr_in *sin = (struct sockaddr_in *)&cu->cu_raddr;
> struct iovec iov;
> - char *cbuf = (char *) alloca (outlen + 256);
> + char *cbuf = (char *) mem_alloc((outlen + 256));
> int ret;
>
> if (cbuf == NULL)
> @@ -462,13 +462,13 @@ get_reply:
> cmsg = CMSG_NXTHDR (&msg, cmsg))
> if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
> {
> - free(cbuf);
> + mem_free(cbuf, (outlen + 256));
> e = (struct sock_extended_err *) CMSG_DATA(cmsg);
> cu->cu_error.re_errno = e->ee_errno;
> release_fd_lock(cu->cu_fd, mask);
> return (cu->cu_error.re_status = RPC_CANTRECV);
> }
> - free(cbuf);
> + mem_free(cbuf, (outlen + 256));
> }
> #endif
>
>
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