From cae13fe4cc3f24820ffb990c09110626837e85d4 Mon Sep 17 00:00:00 2001
From: Timo Warns <Warns@pre-sense.de>
Date: Thu, 19 May 2011 09:24:17 +0200
Subject: [PATCH] Fix for buffer overflow in ldm_frag_add not sufficient
As Ben Hutchings discovered [1], the patch for CVE-2011-1017 (buffer
overflow in ldm_frag_add) is not sufficient. The original patch in
commit c340b1d64000 ("fs/partitions/ldm.c: fix oops caused by corrupted
partition table") does not consider that, for subsequent fragments,
previously allocated memory is used.
[1] http://lkml.org/lkml/2011/5/6/407
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Timo Warns <warns@pre-sense.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
fs/partitions/ldm.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/fs/partitions/ldm.c b/fs/partitions/ldm.c
index ce4f62440425..a29d5ccf3d54 100644
--- a/fs/partitions/ldm.c
+++ b/fs/partitions/ldm.c
@@ -1335,6 +1335,11 @@ static bool ldm_frag_add (const u8 *data, int size, struct list_head *frags)
list_add_tail (&f->list, frags);
found:
+ if (rec >= f->num) {
+ ldm_error("REC value (%d) exceeds NUM value (%d)", rec, f->num);
+ return false;
+ }
+
if (f->map & (1 << rec)) {
ldm_error ("Duplicate VBLK, part %d.", rec);
f->map &= 0x7F; /* Mark the group as broken */
--
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