linux-kernel - [PATCH] fix integer overflow in groups

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <4C7FC0B4.3040005@redhat.com>
Date:	Thu, 02 Sep 2010 17:20:20 +0200
From:	Jerome Marchand <jmarchan@...hat.com>
To:	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: [PATCH] fix integer overflow in groups_search


gid_t is a unsigned int. If group_info contains a gid greater than
MAX_INT, groups_search() function may look on the wrong side of the 
search tree.
This solves some unfair "permission denied" problems.

Signed-off-by: Jerome Marchand <jmarchan@...hat.com>
---
diff --git a/kernel/groups.c b/kernel/groups.c
index 53b1916..253dc0f 100644
--- a/kernel/groups.c
+++ b/kernel/groups.c
@@ -143,10 +143,9 @@ int groups_search(const struct group_info *group_info, gid_t grp)
 	right = group_info->ngroups;
 	while (left < right) {
 		unsigned int mid = (left+right)/2;
-		int cmp = grp - GROUP_AT(group_info, mid);
-		if (cmp > 0)
+		if (grp > GROUP_AT(group_info, mid))
 			left = mid + 1;
-		else if (cmp < 0)
+		else if (grp < GROUP_AT(group_info, mid))
 			right = mid;
 		else
 			return 1;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/