| Date | Sun, 05 Feb 2012 23:10:02 +0100 | From | Willy Tarreau <> | Subject | [PATCH 13/91] fs/partitions/ldm.c: fix oops caused by corrupted partition table |
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2.6.27-longterm review patch. If anyone has any objections, please let us know.
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commit c340b1d640001c8c9ecff74f68fd90422ae2448a upstream.
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 <warns@pre-sense.de> Cc: Eugene Teo <eugeneteo@kernel.sg> Cc: Harvey Harrison <harvey.harrison@gmail.com> Cc: Richard Russon <rich@flatcap.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> --- fs/partitions/ldm.c | 16 ++++++++++++---- 1 files changed, 12 insertions(+), 4 deletions(-)
Index: longterm-2.6.27/fs/partitions/ldm.c =================================================================== --- longterm-2.6.27.orig/fs/partitions/ldm.c 2012-02-05 22:34:34.635914935 +0100 +++ longterm-2.6.27/fs/partitions/ldm.c 2012-02-05 22:34:36.759915873 +0100 @@ -1299,6 +1299,11 @@ 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 @@ 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 @@ 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;
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