Commit 5c2e9f34 authored Aug 29, 2019 by Mark Salyzyn Committed by Miklos Szeredi Sep 11, 2019

ovl: filter of trusted xattr results in audit



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@android.com>
Cc: linux-security-module@vger.kernel.org
Cc: kernel-team@android.com
Cc: stable@vger.kernel.org # v3.18+
Fixes: a082c6f6 ("ovl: filter trusted xattr for non-admin")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>

parent 97f024b9

fs/overlayfs/inode.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -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)

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