From c340b1d640001c8c9ecff74f68fd90422ae2448a Mon Sep 17 00:00:00 2001 From: Timo Warns Date: Thu, 14 Apr 2011 15:21:56 -0700 Subject: [PATCH] fs/partitions/ldm.c: fix oops caused by corrupted partition table 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 --- fs/partitions/ldm.c | 16 ++++++++++++---- 1 file changed, 12 insertions(+), 4 deletions(-) diff --git a/fs/partitions/ldm.c b/fs/partitions/ldm.c index b10e3540d5b7..ce4f62440425 100644 --- a/fs/partitions/ldm.c +++ b/fs/partitions/ldm.c @@ -1299,6 +1299,11 @@ 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 = get_unaligned_be32(data + 0x08); rec = get_unaligned_be16(data + 0x0C); num = get_unaligned_be16(data + 0x0E); @@ -1306,6 +1311,10 @@ 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); @@ -1334,10 +1343,9 @@ 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; -- 2.34.1