Attachment 90138 Details for Bug 72253 – The patch to fix the problem.

The patch to fix the problem.

0001-Test-the-value-of-msg_controllen-for-platforms-whose.patch (text/plain), 1.66 KB, created by PHO on 2013-12-03 04:03:02 UTC

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Creator: PHO

Created: 2013-12-03 04:03:02 UTC

Size: 1.66 KB

patch

obsolete

>From 2ef339009976dda85ff702b92de1f98625602b0a Mon Sep 17 00:00:00 2001
>From: PHO <pho@cielonegro.org>
>Date: Tue, 3 Dec 2013 12:43:04 +0900
>Subject: [PATCH] Test the value of msg_controllen for platforms whose
> CMSG_FIRSTHDR() does not test it for us.
>
>As RFC 2292 points out, some platforms (e.g. Darwin 9.8.0) provide CMSG_FIRSTHDR(msg) which just returns msg.msg_control without first checking if msg.msg_controllen is non-zero. We need a workaround for such platforms not to let _xcb_in_read() segfault.
>---
> src/xcb_in.c | 12 +++++++-----
> 1 file changed, 7 insertions(+), 5 deletions(-)
>
>diff --git a/src/xcb_in.c b/src/xcb_in.c
>index fd6c2ef..95087be 100644
>--- a/src/xcb_in.c
>+++ b/src/xcb_in.c
>@@ -918,11 +918,13 @@ int _xcb_in_read(xcb_connection_t *c)
> #if HAVE_SENDMSG
>         struct cmsghdr *hdr;
> 
>-        for (hdr = CMSG_FIRSTHDR(&msg); hdr; hdr = CMSG_NXTHDR(&msg, hdr)) {
>-            if (hdr->cmsg_level == SOL_SOCKET && hdr->cmsg_type == SCM_RIGHTS) {
>-                int nfd = (hdr->cmsg_len - CMSG_LEN(0)) / sizeof (int);
>-                memcpy(&c->in.in_fd.fd[c->in.in_fd.nfd], CMSG_DATA(hdr), nfd * sizeof (int));
>-                c->in.in_fd.nfd += nfd;
>+        if (msg.msg_controllen >= sizeof (struct cmsghdr)) {
>+            for (hdr = CMSG_FIRSTHDR(&msg); hdr; hdr = CMSG_NXTHDR(&msg, hdr)) {
>+                if (hdr->cmsg_level == SOL_SOCKET && hdr->cmsg_type == SCM_RIGHTS) {
>+                    int nfd = (hdr->cmsg_len - CMSG_LEN(0)) / sizeof (int);
>+                    memcpy(&c->in.in_fd.fd[c->in.in_fd.nfd], CMSG_DATA(hdr), nfd * sizeof (int));
>+                    c->in.in_fd.nfd += nfd;
>+                }
>             }
>         }
> #endif
>-- 
>1.8.4.3
>

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