Since kernel symbols are resolvable internally to the kernel, the kernel
itself has a map of the symbols. Continuing the tradition of frustrating
off-the-shelf kernel exploits, make vmlinuz unreadable for non-root, just
like has been done for System.map, etc.

Signed-off-by: Kees Cook <kees.cook@canonical.com>
---
debian/rules.d/2-binary-arch.mk | 4 ++--
debian/scripts/sub-flavour | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/debian/rules.d/2-binary-arch.mk b/debian/rules.d/2-binary-arch.mk
index c31ab14..9765ef7 100644
--- a/debian/rules.d/2-binary-arch.mk
+++ b/debian/rules.d/2-binary-arch.mk
@@ -54,13 +54,13 @@ install-%: $(stampdir)/stamp-build-% checks-%
# compress_file logic required because not all architectures
# generate a zImage automatically out of the box
ifeq ($(compress_file),)
- install -m644 -D $(builddir)/build-$*/$(kernel_file)
+ install -m600 -D $(builddir)/build-$*/$(kernel_file)
$(pkgdir)/boot/$(install_file)-$(abi_release)-$*
else
install -d $(pkgdir)/boot
gzip -c9v $(builddir)/build-$*/$(kernel_file) >
$(pkgdir)/boot/$(install_file)-$(abi_release)-$*
- chmod 644 $(pkgdir)/boot/$(install_file)-$(abi_release)-$*
+ chmod 600 $(pkgdir)/boot/$(install_file)-$(abi_release)-$*
endif

install -m644 $(builddir)/build-$*/.config
diff --git a/debian/scripts/sub-flavour b/debian/scripts/sub-flavour
index 45456bb..0100493 100644
--- a/debian/scripts/sub-flavour
+++ b/debian/scripts/sub-flavour
@@ -11,9 +11,9 @@ from_moddir="debian/$from_pkg/lib/modules/$ABI_RELEASE-$FROM"
to_moddir="debian/$to_pkg/lib/modules/$ABI_RELEASE-$FROM"

install -d "debian/$to_pkg/boot"
-install -m644 debian/$from_pkg/boot/{vmlinuz,config}-$ABI_RELEASE-$FROM
+install -m644 debian/$from_pkg/boot/config-$ABI_RELEASE-$FROM
debian/$to_pkg/boot/
-install -m600 debian/$from_pkg/boot/System.map-$ABI_RELEASE-$FROM
+install -m600 debian/$from_pkg/boot/{vmlinuz,System.map}-$ABI_RELEASE-$FROM
debian/$to_pkg/boot/

#
--
1.7.4.1

--
Kees Cook
Ubuntu Security Team

--
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