From: Amir Goldstein Date: Sat, 19 Dec 2020 10:05:27 +0000 (+0200) Subject: selinux: fix inconsistency between inode_getxattr and inode_listsecurity X-Git-Tag: v5.10.25~633 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=2fe92153013c490f739e6862c08848126501f172;p=platform%2Fkernel%2Flinux-rpi.git selinux: fix inconsistency between inode_getxattr and inode_listsecurity commit a9ffe682c58aaff643764547f5420e978b6e0830 upstream. When inode has no listxattr op of its own (e.g. squashfs) vfs_listxattr calls the LSM inode_listsecurity hooks to list the xattrs that LSMs will intercept in inode_getxattr hooks. When selinux LSM is installed but not initialized, it will list the security.selinux xattr in inode_listsecurity, but will not intercept it in inode_getxattr. This results in -ENODATA for a getxattr call for an xattr returned by listxattr. This situation was manifested as overlayfs failure to copy up lower files from squashfs when selinux is built-in but not initialized, because ovl_copy_xattr() iterates the lower inode xattrs by vfs_listxattr() and vfs_getxattr(). Match the logic of inode_listsecurity to that of inode_getxattr and do not list the security.selinux xattr if selinux is not initialized. Reported-by: Michael Labriola Tested-by: Michael Labriola Link: https://lore.kernel.org/linux-unionfs/2nv9d47zt7.fsf@aldarion.sourceruckus.org/ Fixes: c8e222616c7e ("selinux: allow reading labels before policy is loaded") Cc: stable@vger.kernel.org#v5.9+ Signed-off-by: Amir Goldstein Reviewed-by: Ondrej Mosnacek Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman --- diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index c463127..227eb89 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -3414,6 +3414,10 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name, static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size) { const int len = sizeof(XATTR_NAME_SELINUX); + + if (!selinux_initialized(&selinux_state)) + return 0; + if (buffer && len <= buffer_size) memcpy(buffer, XATTR_NAME_SELINUX, len); return len;