From patchwork Tue Apr 26 18:44:56 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Dapper, CVE-2011-1017, 1/1] fs/partitions/ldm.c: fix oops caused by corrupted partition table, CVE-2011-1017 Date: Tue, 26 Apr 2011 08:44:56 -0000 From: Brad Figg X-Patchwork-Id: 92948 Message-Id: <1303843496-8390-1-git-send-email-brad.figg@canonical.com> To: kernel-team@lists.ubuntu.com From: Timo Warns BugLink: http://bugs.launchpad.net/bugs/771382 CVE-2011-1017 The kernel automatically evaluates partition tables of storage devices. The code for evaluating LDM partitions (in fs/partitions/ldm.c) contains a bug that causes a kernel oops on certain corrupted LDM partitions. A kernel subsystem seems to crash, because, after the oops, the kernel no longer recognizes newly connected storage devices. The patch validates the value of vblk_size. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Timo Warns Cc: Eugene Teo Cc: Harvey Harrison Cc: Richard Russon Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds (backported from commit c340b1d640001c8c9ecff74f68fd90422ae2448a) Signed-off-by: Brad Figg Acked-by: Steve Conklin Acked-by: Stefan Bader --- fs/partitions/ldm.c | 16 ++++++++++++---- 1 files changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/partitions/ldm.c b/fs/partitions/ldm.c index 7ab1c11..c861f52 100644 --- a/fs/partitions/ldm.c +++ b/fs/partitions/ldm.c @@ -1225,6 +1225,11 @@ static BOOL ldm_frag_add (const u8 *data, int size, struct list_head *frags) BUG_ON (!data || !frags); + if (size < 2 * VBLK_SIZE_HEAD) { + ldm_error("Value of size is to small."); + return FALSE; + } + group = BE32 (data + 0x08); rec = BE16 (data + 0x0C); num = BE16 (data + 0x0E); @@ -1232,6 +1237,10 @@ static BOOL ldm_frag_add (const u8 *data, int size, struct list_head *frags) ldm_error ("A VBLK claims to have %d parts.", num); return FALSE; } + if (rec >= num) { + ldm_error("REC value (%d) exceeds NUM value (%d)", rec, num); + return FALSE; + } list_for_each (item, frags) { f = list_entry (item, struct frag, list); @@ -1260,10 +1269,9 @@ found: f->map |= (1 << rec); - if (num > 0) { - data += VBLK_SIZE_HEAD; - size -= VBLK_SIZE_HEAD; - } + data += VBLK_SIZE_HEAD; + size -= VBLK_SIZE_HEAD; + memcpy (f->data+rec*(size-VBLK_SIZE_HEAD)+VBLK_SIZE_HEAD, data, size); return TRUE;