From 4e9cca830222266bc4d456d0ce7f13a376088e56 Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Thu, 26 Jul 2012 14:47:11 -0700 Subject: [PATCH] smack: off by one error commit 3b9fc37280c521b086943f9aedda767f5bf3b2d3 upstream. Consider the input case of a rule that consists entirely of non space symbols followed by a \0. Say 64 + \0 In this case strlen(data) = 64 kzalloc of subject and object are 64 byte objects sscanfdata, "%s %s %s", subject, ...) will put 65 bytes into subject. Signed-off-by: Alan Cox Acked-by: Casey Schaufler Signed-off-by: James Morris Signed-off-by: Greg Kroah-Hartman --- security/smack/smackfs.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 1810c9a4ed48..cb6d904e3f96 100644 --- a/security/smack/smackfs.c +++ b/security/smack/smackfs.c @@ -325,11 +325,11 @@ static int smk_parse_long_rule(const char *data, struct smack_rule *rule, int datalen; int rc = -1; - /* - * This is probably inefficient, but safe. - */ + /* This is inefficient */ datalen = strlen(data); - subject = kzalloc(datalen, GFP_KERNEL); + + /* Our first element can be 64 + \0 with no spaces */ + subject = kzalloc(datalen + 1, GFP_KERNEL); if (subject == NULL) return -1; object = kzalloc(datalen, GFP_KERNEL); -- 2.39.5