When filtering xattr list for reading, presence of trusted xattr results in a security audit log. However, if there is other content no errno will be set, and if there isn't, the errno will be -ENODATA and not -EPERM as is usually associated with a lack of capability. The check does not block the request to list the xattrs present. Switch to ns_capable_noaudit to reflect a more appropriate check. Signed-off-by: Mark Salyzyn <salyzyn@xxxxxxxxxxx> Cc: linux-kernel@xxxxxxxxxxxxxxxx Cc: linux-security-module@xxxxxxxxxxxxxxx Cc: kernel-team@xxxxxxxxxxx Cc: stable@xxxxxxxxxxxxxxx # 4.4, 4.9, 4.14 & 4.19 --- fs/overlayfs/inode.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 7663aeb85fa3..bc14781886bf 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -383,7 +383,8 @@ static bool ovl_can_list(const char *s) return true; /* Never list trusted.overlay, list other trusted for superuser only */ - return !ovl_is_private_xattr(s) && capable(CAP_SYS_ADMIN); + return !ovl_is_private_xattr(s) && + ns_capable_noaudit(&init_user_ns, CAP_SYS_ADMIN); } ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) -- 2.23.0.187.g17f5b7556c-goog
