linux-kernel - [PATCH 3.4 097/214] md/raid10: fix "enough" function for detecting if array is failed.

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 for Android: free password hash cracker in your pocket

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

Message-Id: <20140605041652.726311171@linuxfoundation.org>
Date:	Wed,  4 Jun 2014 21:17:40 -0700
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org,
	Jakub Husák <jakub@...seman.cz>,
	NeilBrown <neilb@...e.de>, Ben Hutchings <ben@...adent.org.uk>,
	Rui Xiang <rui.xiang@...wei.com>
Subject: [PATCH 3.4 097/214] md/raid10: fix "enough" function for detecting if array is failed.

3.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: NeilBrown <neilb@...e.de>

commit 80b4812407c6b1f66a4f2430e69747a13f010839 upstream.

The 'enough' function is written to work with 'near' arrays only
in that is implicitly assumes that the offset from one 'group' of
devices to the next is the same as the number of copies.
In reality it is the number of 'near' copies.

So change it to make this number explicit.

This bug makes it possible to run arrays without enough drives
present, which is dangerous.
It is appropriate for an -stable kernel, but will almost certainly
need to be modified for some of them.

Reported-by: Jakub Husák <jakub@...seman.cz>
Signed-off-by: NeilBrown <neilb@...e.de>
[bwh: Backported to 3.2: s/geo->/conf->/]
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
Cc: Rui Xiang <rui.xiang@...wei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/md/raid10.c |    8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1419,14 +1419,16 @@ static int enough(struct r10conf *conf,
 	do {
 		int n = conf->copies;
 		int cnt = 0;
+		int this = first;
 		while (n--) {
-			if (conf->mirrors[first].rdev &&
-			    first != ignore)
+			if (conf->mirrors[this].rdev &&
+			    this != ignore)
 				cnt++;
-			first = (first+1) % conf->raid_disks;
+			this = (this+1) % conf->raid_disks;
 		}
 		if (cnt == 0)
 			return 0;
+		first = (first + conf->near_copies) % conf->raid_disks;
 	} while (first != 0);
 	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/