From: Ruediger Meier <ruediger.meier@ga-group.nl>
Date: Fri, 18 Mar 2016 11:49:17 +0000 (+0100)
Subject: ipcs: make sure to parse whole lines for shm_data
X-Git-Tag: v2.28-rc2~21
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=97fab80eaf210fb23e106a2cd4ec6dd998cd520d;p=thirdparty%2Futil-linux.git

ipcs: make sure to parse whole lines for shm_data

We want to parse 16 columns _per_row_ without mixing them up. The
existing code is unsafe for more or less columns and could even
run into endless loops. This patch assures that we parse row-wise
and really skip lines with columns != 16.

Probably somehow we could have also done this with fscanf() only.
Using fgets() additionally makes the code more easy to read and
to improve later.

Signed-off-by: Ruediger Meier <ruediger.meier@ga-group.nl>
---

diff --git a/sys-utils/ipcutils.c b/sys-utils/ipcutils.c
index 400f00cf66..c763cde696 100644
--- a/sys-utils/ipcutils.c
+++ b/sys-utils/ipcutils.c
@@ -99,6 +99,7 @@ int ipc_shm_get_info(int id, struct shm_data **shmds)
 {
 	FILE *f;
 	int i = 0, maxid;
+	char buf[BUFSIZ];
 	struct shm_data *p;
 	struct shmid_ds dummy;
 
@@ -111,8 +112,8 @@ int ipc_shm_get_info(int id, struct shm_data **shmds)
 
 	while (fgetc(f) != '\n');		/* skip header */
 
-	while (feof(f) == 0) {
-		if (fscanf(f,
+	while (fgets(buf, sizeof(buf), f) != NULL) {
+		if (sscanf(buf,
 			  "%d %d  %o %"SCNu64 " %u %u  "
 			  "%"SCNu64 " %u %u %u %u %"SCNi64 " %"SCNi64 " %"SCNi64
 			  " %"SCNu64 " %"SCNu64 "\n",
@@ -132,7 +133,7 @@ int ipc_shm_get_info(int id, struct shm_data **shmds)
 			   &p->shm_ctim,
 			   &p->shm_rss,
 			   &p->shm_swp) != 16)
-			continue;
+			continue; /* ivalid line, skipped */
 
 		if (id > -1) {
 			/* ID specified */