From 91c9c9ec54c1e88d9ef59a7b12cf31d6ef5d1e58 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Thu, 8 Feb 2018 17:39:01 +0100 Subject: [PATCH] udf: Fix off-by-one in volume descriptor sequence length MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit We pass one block beyond end of volume descriptor sequence into process_sequence() as 'lastblock' instead of the last block of the sequence. When the sequence is not terminated with TD descriptor, this could lead to false errors due to invalid blocks in volume descriptor sequence and thus unmountable volumes. Acked-by: Pali Rohár Signed-off-by: Jan Kara --- fs/udf/super.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/udf/super.c b/fs/udf/super.c index f73239a9a97d..5c5d5fd513cc 100644 --- a/fs/udf/super.c +++ b/fs/udf/super.c @@ -1658,7 +1658,7 @@ static noinline int udf_process_sequence( next_e = le32_to_cpu( vdp->nextVolDescSeqExt.extLength); next_e = next_e >> sb->s_blocksize_bits; - next_e += next_s; + next_e += next_s - 1; } break; case TAG_IDENT_IUVD: /* ISO 13346 3/10.4 */ @@ -1760,13 +1760,13 @@ static int udf_load_sequence(struct super_block *sb, struct buffer_head *bh, main_s = le32_to_cpu(anchor->mainVolDescSeqExt.extLocation); main_e = le32_to_cpu(anchor->mainVolDescSeqExt.extLength); main_e = main_e >> sb->s_blocksize_bits; - main_e += main_s; + main_e += main_s - 1; /* Locate the reserve sequence */ reserve_s = le32_to_cpu(anchor->reserveVolDescSeqExt.extLocation); reserve_e = le32_to_cpu(anchor->reserveVolDescSeqExt.extLength); reserve_e = reserve_e >> sb->s_blocksize_bits; - reserve_e += reserve_s; + reserve_e += reserve_s - 1; /* Process the main & reserve sequences */ /* responsible for finding the PartitionDesc(s) */ -- 2.30.2