From: Russell King rmk+kernel@armlinux.org.uk
[ 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@armlinux.org.uk Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Sasha Levin sashal@kernel.org --- 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 "