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 Aurele La France tsi@tuyoix.net Tested-by: Marc Aurèle La France tsi@tuyoix.net Signed-off-by: Andreas Gruenbacher agruenba@redhat.com CC: Stable stable@vger.kernel.org # v4.5+ --- fs/xattr.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-)
diff --git a/fs/xattr.c b/fs/xattr.c index daa732550088..0d6a6a4af861 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -948,17 +948,19 @@ ssize_t simple_xattr_list(struct inode *inode, struct simple_xattrs *xattrs, 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