Messages in this thread Patch in this message | | | From | Sasha Levin <> | Subject | [PATCH AUTOSEL 4.9 09/30] fs/adfs: super: fix use-after-free bug | Date | Fri, 26 Jul 2019 09:44:11 -0400 |
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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 c9fdfb112933..e42c30001509 100644 --- a/fs/adfs/super.c +++ b/fs/adfs/super.c @@ -368,6 +368,7 @@ 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; @@ -419,8 +420,10 @@ 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
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