ext4: fix possible use after free in ext4_quota_enable (61157b24) · Commits · 戴 / test

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: ("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>

fs/ext4/super.c

+1 −1

Original line number	Original line	Diff line number	Diff line
	@@ -5713,9 +5713,9 @@ static int ext4_quota_enable(struct super_block *sb, int type, int format_id,
	qf_inode->i_flags \|= S_NOQUOTA;		qf_inode->i_flags \|= S_NOQUOTA;
	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_QUOTA);
	err = dquot_enable(qf_inode, type, format_id, flags);		err = dquot_enable(qf_inode, type, format_id, flags);
	iput(qf_inode);
	if (err)		if (err)
	lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);		lockdep_set_quota_inode(qf_inode, I_DATA_SEM_NORMAL);
			iput(qf_inode);

	return err;		return err;
	}		}

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