| From 61157b24e60fb3cd1f85f2c76a7b1d628f970144 Mon Sep 17 00:00:00 2001 |
| From: Pan Bian <bianpan2016@163.com> |
| Date: Mon, 3 Dec 2018 23:28:02 -0500 |
| Subject: ext4: fix possible use after free in ext4_quota_enable |
| |
| From: Pan Bian <bianpan2016@163.com> |
| |
| commit 61157b24e60fb3cd1f85f2c76a7b1d628f970144 upstream. |
| |
| The function frees qf_inode via iput but then pass qf_inode to |
| lockdep_set_quota_inode on the failure path. This may result in a |
| use-after-free bug. The patch frees df_inode only when it is never used. |
| |
| Fixes: daf647d2dd5 ("ext4: add lockdep annotations for i_data_sem") |
| Cc: stable@kernel.org # 4.6 |
| Reviewed-by: Jan Kara <jack@suse.cz> |
| Signed-off-by: Pan Bian <bianpan2016@163.com> |
| Signed-off-by: Theodore Ts'o <tytso@mit.edu> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/ext4/super.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/fs/ext4/super.c |
| +++ b/fs/ext4/super.c |
| @@ -5425,9 +5425,9 @@ static int ext4_quota_enable(struct supe |
| qf_inode->i_flags |= S_NOQUOTA; |
| lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA); |
| err = dquot_enable(qf_inode, type, format_id, flags); |
| - iput(qf_inode); |
| if (err) |
| lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL); |
| + iput(qf_inode); |
| |
| return err; |
| } |
