From: Andreas Gruenbacher Date: Tue, 18 Sep 2018 04:36:36 +0000 (-0400) Subject: sysfs: Do not return POSIX ACL xattrs via listxattr X-Git-Tag: v4.9.132~9 X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=8e9817c6ee3fb22061cd5864e844c4b3b7c8545c;p=linux sysfs: Do not return POSIX ACL xattrs via listxattr 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 Tested-by: Marc Aurèle La France Signed-off-by: Andreas Gruenbacher Cc: stable@vger.kernel.org # v4.5+ Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman --- diff --git a/fs/xattr.c b/fs/xattr.c index 093998872329..2f6423182301 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -953,17 +953,19 @@ 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