Messages in this thread | | | Date | Mon, 7 Oct 2019 18:17:25 +0200 | From | Greg Kroah-Hartman <> | Subject | Re: [PATCH] ovl: filter of trusted xattr results in audit |
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On Mon, Oct 07, 2019 at 06:16:16PM +0200, Greg Kroah-Hartman wrote: > On Mon, Oct 07, 2019 at 09:09:16AM -0700, Mark Salyzyn wrote: > > 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 has_capability_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: Greg Kroah-Hartman <gregkh@linuxfoundation.org> > > Cc: stable@vger.kernel.org # v3.18 > > Fixes: upstream a082c6f680da ("ovl: filter trusted xattr for non-admin") > > Fixes: 3.18 4bcc9b4b3a0a ("ovl: filter trusted xattr for non-admin") > > --- > > Replaced ns_capable_noaudit with 3.18.y tree specific > > has_capability_noaudit present in original submission to kernel.org > > commit 5c2e9f346b815841f9bed6029ebcb06415caf640 > > ("ovl: filter of trusted xattr results in audit") > > > > 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 a01ec1836a72..1175efa5e956 100644 > > --- a/fs/overlayfs/inode.c > > +++ b/fs/overlayfs/inode.c > > @@ -265,7 +265,8 @@ 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) && > > + has_capability_noaudit(current, CAP_SYS_ADMIN); > > } > > > > ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size) > > -- > > 2.23.0.581.g78d2f28ef7-goog > > > > Thanks for the backport, this one worked!
I spoke too soon:
ERROR: "has_capability_noaudit" [fs/overlayfs/overlay.ko] undefined!
That function isn't exported for modules :(
greg k-h
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