From: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
[ Upstream commit 5808b14a1f52554de612fee85ef517199855e310 ]
Fix a use-after-free bug during filesystem initialisation, where we
access the disc record (which is stored in a buffer) after we have
released the buffer.
Signed-off-by: Russell King <rmk+kernel@xxxxxxxxxxxxxxx>
Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/adfs/super.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index ffb669f9bba7..ce0fbbe002bf 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -360,6 +360,7 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
struct buffer_head *bh;
struct object_info root_obj;
unsigned char *b_data;
+ unsigned int blocksize;
struct adfs_sb_info *asb;
struct inode *root;
int ret = -EINVAL;
@@ -411,8 +412,10 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
goto error_free_bh;
}
+ blocksize = 1 << dr->log2secsize;
brelse(bh);
- if (sb_set_blocksize(sb, 1 << dr->log2secsize)) {
+
+ if (sb_set_blocksize(sb, blocksize)) {
bh = sb_bread(sb, ADFS_DISCRECORD / sb->s_blocksize);
if (!bh) {
adfs_error(sb, "couldn't read superblock on "
--
2.20.1
