gfs2: Get rid of potential double-freeing in gfs2_create_inode

In gfs2_create_inode, after setting and releasing the acl / default_acl, the
acl / default_acl pointers are not set to NULL as they should be.  In that
state, when the function reaches label fail_free_acls, gfs2_create_inode will
try to release the same acls again.

Fix that by setting the pointers to NULL after releasing the acls.  Slightly
simplify the logic.  Also, posix_acl_release checks for NULL already, so
there is no need to duplicate those checks here.

Fixes: e01580bf9e ("gfs2: use generic posix ACL infrastructure")
Reported-by: Pan Bian <bianpan2016@163.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # v4.9+
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
This commit is contained in:
Andreas Gruenbacher 2018-11-26 18:45:35 +01:00
parent cbbe76c8bb
commit 6ff9b09e00

View File

@ -744,17 +744,19 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
the gfs2 structures. */ the gfs2 structures. */
if (default_acl) { if (default_acl) {
error = __gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT); error = __gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
if (error)
goto fail_gunlock3;
posix_acl_release(default_acl); posix_acl_release(default_acl);
default_acl = NULL;
} }
if (acl) { if (acl) {
if (!error) error = __gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS);
error = __gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS); if (error)
goto fail_gunlock3;
posix_acl_release(acl); posix_acl_release(acl);
acl = NULL;
} }
if (error)
goto fail_gunlock3;
error = security_inode_init_security(&ip->i_inode, &dip->i_inode, name, error = security_inode_init_security(&ip->i_inode, &dip->i_inode, name,
&gfs2_initxattrs, NULL); &gfs2_initxattrs, NULL);
if (error) if (error)
@ -789,10 +791,8 @@ fail_free_inode:
} }
gfs2_rsqa_delete(ip, NULL); gfs2_rsqa_delete(ip, NULL);
fail_free_acls: fail_free_acls:
if (default_acl) posix_acl_release(default_acl);
posix_acl_release(default_acl); posix_acl_release(acl);
if (acl)
posix_acl_release(acl);
fail_gunlock: fail_gunlock:
gfs2_dir_no_add(&da); gfs2_dir_no_add(&da);
gfs2_glock_dq_uninit(ghs); gfs2_glock_dq_uninit(ghs);