4.18-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andreas Gruenbacher agruenba@redhat.com
commit ffc4c92227db5699493e43eb140b4cb5904c30ff upstream.
Commit 786534b92f3c introduced a regression that caused listxattr to return the POSIX ACL attribute names even though sysfs doesn't support POSIX ACLs. This happens because simple_xattr_list checks for NULL i_acl / i_default_acl, but inode_init_always initializes those fields to ACL_NOT_CACHED ((void *)-1). For example: $ getfattr -m- -d /sys /sys: system.posix_acl_access: Operation not supported /sys: system.posix_acl_default: Operation not supported Fix this in simple_xattr_list by checking if the filesystem supports POSIX ACLs.
Fixes: 786534b92f3c ("tmpfs: listxattr should include POSIX ACL xattrs") Reported-by: Marc Aurèle La France tsi@tuyoix.net Tested-by: Marc Aurèle La France tsi@tuyoix.net Signed-off-by: Andreas Gruenbacher agruenba@redhat.com Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Al Viro viro@zeniv.linux.org.uk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/xattr.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)
--- a/fs/xattr.c +++ b/fs/xattr.c @@ -949,17 +949,19 @@ ssize_t simple_xattr_list(struct inode * int err = 0;
#ifdef CONFIG_FS_POSIX_ACL - if (inode->i_acl) { - err = xattr_list_one(&buffer, &remaining_size, - XATTR_NAME_POSIX_ACL_ACCESS); - if (err) - return err; - } - if (inode->i_default_acl) { - err = xattr_list_one(&buffer, &remaining_size, - XATTR_NAME_POSIX_ACL_DEFAULT); - if (err) - return err; + if (IS_POSIXACL(inode)) { + if (inode->i_acl) { + err = xattr_list_one(&buffer, &remaining_size, + XATTR_NAME_POSIX_ACL_ACCESS); + if (err) + return err; + } + if (inode->i_default_acl) { + err = xattr_list_one(&buffer, &remaining_size, + XATTR_NAME_POSIX_ACL_DEFAULT); + if (err) + return err; + } } #endif