[PATCH]kexec-tools: Fix possible out-of-bounds access in ifdown

[PATCH]kexec-tools: Fix possible out-of-bounds access in ifdown

[Helge Deller]

Fix a possible out-of-bounds access in function ifdown():

ifdown.c: In function 'ifdown':
ifdown.c:56:4: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation]
   56 |    strncpy(ifr.ifr_name, ifp->if_name, IFNAMSIZ);

Signed-off-by: Helge Deller <deller@gmx.de>

diff --git a/kexec/ifdown.c b/kexec/ifdown.c
index 9679ad7..3ac19c1 100644
--- a/kexec/ifdown.c
+++ b/kexec/ifdown.c
@@ -53,7 +53,8 @@ int ifdown(void)
 			if (strchr(ifp->if_name, ':') != NULL)
 				continue;

-			strncpy(ifr.ifr_name, ifp->if_name, IFNAMSIZ);
+			strncpy(ifr.ifr_name, ifp->if_name, IFNAMSIZ-1);
+			ifr.ifr_name[IFNAMSIZ-1] = 0;
 			if (ioctl(fd, SIOCGIFFLAGS, &ifr) < 0) {
 				fprintf(stderr, "ifdown: shutdown ");
 				perror(ifp->if_name);

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec

Re: [PATCH]kexec-tools: Fix possible out-of-bounds access in ifdown

[Simon Horman]

On Tue, Oct 01, 2019 at 05:06:05PM +0200, Helge Deller wrote:
> Fix a possible out-of-bounds access in function ifdown():
> 
> ifdown.c: In function 'ifdown':
> ifdown.c:56:4: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation]
>    56 |    strncpy(ifr.ifr_name, ifp->if_name, IFNAMSIZ);
> 

Thanks, applied.

_______________________________________________
kexec mailing list
kexec@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/kexec