4.9-stable review patch. If anyone has any objections, please let me know.
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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; }