lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-07-28 00:21:52 +03:00
Code Activity

CVE-2016-4429: sunrpc: Do not use alloca in clntudp_call [BZ #20112]

Browse Source 
The call is technically in a loop, and under certain circumstances
(which are quite difficult to reproduce in a test case), alloca
can be invoked repeatedly during a single call to clntudp_call.
As a result, the available stack space can be exhausted (even
though individual alloca sizes are bounded implicitly by what
can fit into a UDP packet, as a side effect of the earlier
successful send operation).
This commit is contained in:
Florian Weimer
2016-05-23 20:18:34 +02:00
parent 3375cfafa7
commit bc779a1a5b
3 changed files with 20 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
sunrpc/clnt_udp.c
View File

@ -388,9 +388,15 @@ send_again:
struct sock_extended_err *e;
struct sockaddr_in err_addr;
struct iovec iov;
char *cbuf = (char *) alloca (outlen + 256);
char *cbuf = malloc (outlen + 256);
int ret;
if (cbuf == NULL)
{
cu->cu_error.re_errno = errno;
return (cu->cu_error.re_status = RPC_CANTRECV);
}
iov.iov_base = cbuf + 256;
iov.iov_len = outlen;
msg.msg_name = (void *) &err_addr;
@ -415,10 +421,12 @@ send_again:
cmsg = CMSG_NXTHDR (&msg, cmsg))
if (cmsg->cmsg_level == SOL_IP && cmsg->cmsg_type == IP_RECVERR)
{
free (cbuf);
e = (struct sock_extended_err *) CMSG_DATA(cmsg);
cu->cu_error.re_errno = e->ee_errno;
return (cu->cu_error.re_status = RPC_CANTRECV);
}
free (cbuf);
}
#endif
do