From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754628Ab2GIOlk (ORCPT ); Mon, 9 Jul 2012 10:41:40 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:38275 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754381Ab2GIOiW (ORCPT ); Mon, 9 Jul 2012 10:38:22 -0400 Message-Id: <20120709143120.604970315@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Mon, 09 Jul 2012 15:31:43 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Jan Kara Subject: [ 27/48] udf: Fortify loading of sparing table In-Reply-To: <20120709143116.348975190@decadent.org.uk> X-SA-Exim-Connect-IP: 2001:470:1f08:1539:21c:bfff:fe03:f805 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jan Kara commit 1df2ae31c724e57be9d7ac00d78db8a5dabdd050 upstream. Add sanity checks when loading sparing table from disk to avoid accessing unallocated memory or writing to it. Signed-off-by: Jan Kara Signed-off-by: Ben Hutchings --- fs/udf/super.c | 86 ++++++++++++++++++++++++++++++++++---------------------- 1 file changed, 53 insertions(+), 33 deletions(-) diff --git a/fs/udf/super.c b/fs/udf/super.c index ce911f5..8d86a87 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -56,6 +56,7 @@ #include #include #include +#include #include #include "udf_sb.h" @@ -1215,11 +1216,59 @@ out_bh: return ret; } +static int udf_load_sparable_map(struct super_block *sb, + struct udf_part_map *map, + struct sparablePartitionMap *spm) +{ + uint32_t loc; + uint16_t ident; + struct sparingTable *st; + struct udf_sparing_data *sdata = &map->s_type_specific.s_sparing; + int i; + struct buffer_head *bh; + + map->s_partition_type = UDF_SPARABLE_MAP15; + sdata->s_packet_len = le16_to_cpu(spm->packetLength); + if (!is_power_of_2(sdata->s_packet_len)) { + udf_err(sb, "error loading logical volume descriptor: " + "Invalid packet length %u\n", + (unsigned)sdata->s_packet_len); + return -EIO; + } + if (spm->numSparingTables > 4) { + udf_err(sb, "error loading logical volume descriptor: " + "Too many sparing tables (%d)\n", + (int)spm->numSparingTables); + return -EIO; + } + + for (i = 0; i < spm->numSparingTables; i++) { + loc = le32_to_cpu(spm->locSparingTable[i]); + bh = udf_read_tagged(sb, loc, loc, &ident); + if (!bh) + continue; + + st = (struct sparingTable *)bh->b_data; + if (ident != 0 || + strncmp(st->sparingIdent.ident, UDF_ID_SPARING, + strlen(UDF_ID_SPARING)) || + sizeof(*st) + le16_to_cpu(st->reallocationTableLen) > + sb->s_blocksize) { + brelse(bh); + continue; + } + + sdata->s_spar_map[i] = bh; + } + map->s_partition_func = udf_get_pblock_spar15; + return 0; +} + static int udf_load_logicalvol(struct super_block *sb, sector_t block, struct kernel_lb_addr *fileset) { struct logicalVolDesc *lvd; - int i, j, offset; + int i, offset; uint8_t type; struct udf_sb_info *sbi = UDF_SB(sb); struct genericPartitionMap *gpm; @@ -1281,38 +1330,9 @@ static int udf_load_logicalvol(struct super_block *sb, sector_t block, } else if (!strncmp(upm2->partIdent.ident, UDF_ID_SPARABLE, strlen(UDF_ID_SPARABLE))) { - uint32_t loc; - struct sparingTable *st; - struct sparablePartitionMap *spm = - (struct sparablePartitionMap *)gpm; - - map->s_partition_type = UDF_SPARABLE_MAP15; - map->s_type_specific.s_sparing.s_packet_len = - le16_to_cpu(spm->packetLength); - for (j = 0; j < spm->numSparingTables; j++) { - struct buffer_head *bh2; - - loc = le32_to_cpu( - spm->locSparingTable[j]); - bh2 = udf_read_tagged(sb, loc, loc, - &ident); - map->s_type_specific.s_sparing. - s_spar_map[j] = bh2; - - if (bh2 == NULL) - continue; - - st = (struct sparingTable *)bh2->b_data; - if (ident != 0 || strncmp( - st->sparingIdent.ident, - UDF_ID_SPARING, - strlen(UDF_ID_SPARING))) { - brelse(bh2); - map->s_type_specific.s_sparing. - s_spar_map[j] = NULL; - } - } - map->s_partition_func = udf_get_pblock_spar15; + if (udf_load_sparable_map(sb, map, + (struct sparablePartitionMap *)gpm) < 0) + goto out_bh; } else if (!strncmp(upm2->partIdent.ident, UDF_ID_METADATA, strlen(UDF_ID_METADATA))) {