From: Jan Kara <jack@suse.cz>
Date: Mon, 16 Oct 2017 09:38:11 +0000 (+0200)
Subject: udf: Avoid overflow when session starts at large offset
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d9490e7ca55bafac97fa65a3d34244386469eb50;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git

udf: Avoid overflow when session starts at large offset


[ Upstream commit abdc0eb06964fe1d2fea6dd1391b734d0590365d ]

When session starts beyond offset 2^31 the arithmetics in
udf_check_vsd() would overflow. Make sure the computation is done in
large enough type.

Reported-by: Cezary Sliwa <sliwa@ifpan.edu.pl>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 99cb81d0077f..08bf097507f6 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -703,7 +703,7 @@ static loff_t udf_check_vsd(struct super_block *sb)
 	else
 		sectorsize = sb->s_blocksize;
 
-	sector += (sbi->s_session << sb->s_blocksize_bits);
+	sector += (((loff_t)sbi->s_session) << sb->s_blocksize_bits);
 
 	udf_debug("Starting at sector %u (%ld byte sectors)\n",
 		  (unsigned int)(sector >> sb->s_blocksize_bits),