From abdc0eb06964fe1d2fea6dd1391b734d0590365d Mon Sep 17 00:00:00 2001
From: Jan Kara <jack@suse.cz>
Date: Mon, 16 Oct 2017 11:38:11 +0200
Subject: [PATCH] udf: Avoid overflow when session starts at large offset
Git-commit: abdc0eb06964fe1d2fea6dd1391b734d0590365d
Patch-mainline: v4.15-rc1
References: bsc#1052766
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>
Acked-by: Jan Kara <jack@suse.cz>
---
fs/udf/super.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
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),
--
2.13.6