[PATCH 37/46][dunfell] grub: fix checking for NULL


Marta Rybczynska
 

This patch adds a fix for checking for NULL in grub's loader/bsd.
It is a part of a security series [1].

[1] https://lists.gnu.org/archive/html/grub-devel/2021-03/msg00007.html

Signed-off-by: Marta Rybczynska <marta.rybczynska@...>
---
...ader-bsd-Check-for-NULL-arg-up-front.patch | 47 +++++++++++++++++++
meta/recipes-bsp/grub/grub2.inc | 1 +
2 files changed, 48 insertions(+)
create mode 100644 meta/recipes-bsp/grub/files/0037-loader-bsd-Check-for-NULL-arg-up-front.patch

diff --git a/meta/recipes-bsp/grub/files/0037-loader-bsd-Check-for-NULL-arg-up-front.patch b/meta/recipes-bsp/grub/files/0037-loader-bsd-Check-for-NULL-arg-up-front.patch
new file mode 100644
index 0000000000..34643e10ab
--- /dev/null
+++ b/meta/recipes-bsp/grub/files/0037-loader-bsd-Check-for-NULL-arg-up-front.patch
@@ -0,0 +1,47 @@
+From 7899384c8fdf9ed96566978c49b0c6e40e70703d Mon Sep 17 00:00:00 2001
+From: Darren Kenny <darren.kenny@...>
+Date: Tue, 8 Dec 2020 21:47:13 +0000
+Subject: [PATCH] loader/bsd: Check for NULL arg up-front
+
+The code in the next block suggests that it is possible for .set to be
+true but .arg may still be NULL.
+
+This code assumes that it is never NULL, yet later is testing if it is
+NULL - that is inconsistent.
+
+So we should check first if .arg is not NULL, and remove this check that
+is being flagged by Coverity since it is no longer required.
+
+Fixes: CID 292471
+
+Signed-off-by: Darren Kenny <darren.kenny@...>
+Reviewed-by: Daniel Kiper <daniel.kiper@...>
+
+Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?id=5d5391b0a05abe76e04c1eb68dcc6cbef5326c4a]
+Signed-off-by: Marta Rybczynska <marta.rybczynska@...>
+---
+ grub-core/loader/i386/bsd.c | 4 ++--
+ 1 file changed, 2 insertions(+), 2 deletions(-)
+
+diff --git a/grub-core/loader/i386/bsd.c b/grub-core/loader/i386/bsd.c
+index b92cbe9..8432283 100644
+--- a/grub-core/loader/i386/bsd.c
++++ b/grub-core/loader/i386/bsd.c
+@@ -1605,7 +1605,7 @@ grub_cmd_openbsd (grub_extcmd_context_t ctxt, int argc, char *argv[])
+ kernel_type = KERNEL_TYPE_OPENBSD;
+ bootflags = grub_bsd_parse_flags (ctxt->state, openbsd_flags);
+
+- if (ctxt->state[OPENBSD_ROOT_ARG].set)
++ if (ctxt->state[OPENBSD_ROOT_ARG].set && ctxt->state[OPENBSD_ROOT_ARG].arg != NULL)
+ {
+ const char *arg = ctxt->state[OPENBSD_ROOT_ARG].arg;
+ unsigned type, unit, part;
+@@ -1622,7 +1622,7 @@ grub_cmd_openbsd (grub_extcmd_context_t ctxt, int argc, char *argv[])
+ "unknown disk type name");
+
+ unit = grub_strtoul (arg, (char **) &arg, 10);
+- if (! (arg && *arg >= 'a' && *arg <= 'z'))
++ if (! (*arg >= 'a' && *arg <= 'z'))
+ return grub_error (GRUB_ERR_BAD_ARGUMENT,
+ "only device specifications of form "
+ "<type><number><lowercase letter> are supported");
diff --git a/meta/recipes-bsp/grub/grub2.inc b/meta/recipes-bsp/grub/grub2.inc
index 1a4be33fca..8b55afccbb 100644
--- a/meta/recipes-bsp/grub/grub2.inc
+++ b/meta/recipes-bsp/grub/grub2.inc
@@ -83,6 +83,7 @@ SRC_URI = "${GNU_MIRROR}/grub/grub-${PV}.tar.gz \
file://0034-video-fb-video_fb-Fix-possible-integer-overflow.patch \
file://0035-video-readers-jpeg-Test-for-an-invalid-next-marker-r.patch \
file://0036-gfxmenu-gui_list-Remove-code-that-coverity-is-flaggi.patch \
+ file://0037-loader-bsd-Check-for-NULL-arg-up-front.patch \
"
SRC_URI[md5sum] = "5ce674ca6b2612d8939b9e6abed32934"
SRC_URI[sha256sum] = "f10c85ae3e204dbaec39ae22fa3c5e99f0665417e91c2cb49b7e5031658ba6ea"
--
2.33.0

Join openembedded-core@lists.openembedded.org to automatically receive all group messages.