Re: [PATCH] e2fsprogs: fix potential null ptr deref in check_for_modules()
From: Eric Sandeen <hidden>
Date: 2009-02-26 22:20:40
Eric Sandeen wrote:
The coverity scanner found this one.
If a line in modules.dep has a ":" but no "/" then:
if ((cp = strchr(buf, ':')) != NULL)
*cp = 0;
else
continue;
if ((cp = strrchr(buf, '/')) != NULL)
cp++;
/* XXX else cp is still null */
i = strlen(cp);
... we will deref a null pointer (cp). This can be
demonstrated by putting a line like:
foo.ko:
into modules.dep. The below change just says that if no "/" is
found, treat the whole string as the module name.FWIW; this resolves RH bugzilla: [Bug 486997] rawhide's init/nash segfaults in libblkid and also is an extension of the patch Jim sent a couple days ago. The issue is that for fedora initrds, anyway, modules dep is something like: crc16.ko: ext4.ko: jbd2.ko crc16.ko ... so it hits exactly this case. -Eric
quoted hunk ↗ jump to hunk
Signed-off-by: Eric Sandeen <redacted> --- Index: e2fsprogs/e2fsck/util.c ===================================================================--- e2fsprogs.orig/e2fsck/util.c +++ e2fsprogs/e2fsck/util.c@@ -663,6 +663,8 @@ int check_for_modules(const char *fs_nam continue; if ((cp = strrchr(buf, '/')) != NULL) cp++; + else + cp = buf; i = strlen(cp); if (i > 3) { t = cp + i - 3;Index: e2fsprogs/lib/blkid/probe.c ===================================================================--- e2fsprogs.orig/lib/blkid/probe.c +++ e2fsprogs/lib/blkid/probe.c@@ -227,6 +227,8 @@ static int check_for_modules(const char continue; if ((cp = strrchr(buf, '/')) != NULL) cp++; + else + cp = buf; i = strlen(cp); if (i > 3) { t = cp + i - 3; --To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html