nasm: fix CVE-2020-21528

A Segmentation Fault issue discovered in in ieee_segment function in outieee.c
in nasm 2.14.03 and 2.15 allows remote attackers to cause a denial of service
via crafted assembly file.

References:
https://nvd.nist.gov/vuln/detail/CVE-2020-21528

Upstream patches:
https://github.com/netwide-assembler/nasm/commit/93c774d482694643cafbc82578ac8b729fb5bc8b

(From OE-Core rev: 87c4ec2d73ac2e52005e16e38a9a12affb8d51bd)

Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

2 files changed, 48 insertions, 0 deletions

diff --git a/meta/recipes-devtools/nasm/nasm/CVE-2020-21528.patch b/meta/recipes-devtools/nasm/nasm/CVE-2020-21528.patch
new file mode 100644
index 0000000000..2303744540
--- /dev/null
+++ b/meta/recipes-devtools/nasm/nasm/CVE-2020-21528.patch
@@ -0,0 +1,47 @@
+From 93c774d482694643cafbc82578ac8b729fb5bc8b Mon Sep 17 00:00:00 2001
+From: Cyrill Gorcunov <gorcunov@gmail.com>
+Date: Wed, 4 Nov 2020 13:08:06 +0300
+Subject: [PATCH] BR3392637: output/outieee: Fix nil dereference
+
+The handling been broken in commit 98578071.
+
+Upstream-Status: Backport [https://github.com/netwide-assembler/nasm/commit/93c774d482694643cafbc82578ac8b729fb5bc8b]
+
+CVE: CVE-2020-21528
+
+Signed-off-by: Cyrill Gorcunov <gorcunov@gmail.com>
+Signed-off-by: Archana Polampalli <archana.polampalli@windriver.com>
+---
+ output/outieee.c | 17 +++++++++++++++++
+ 1 file changed, 17 insertions(+)
+
+diff --git a/output/outieee.c b/output/outieee.c
+index bff2f085..b3ccc5f6 100644
+--- a/output/outieee.c
++++ b/output/outieee.c
+@@ -795,6 +795,23 @@ static int32_t ieee_segment(char *name, int *bits)
+             define_label(name, seg->index + 1, 0L, false);
+         ieee_seg_needs_update = NULL;
+
++        /*
++         * In commit 98578071b9d71ecaa2344dd9c185237c1765041e
++         * we reworked labels significantly which in turn lead
++         * to the case where seg->name = NULL here and we get
++         * nil dereference in next segments definitions.
++         *
++         * Lets placate this case with explicit name setting
++         * if labels engine didn't set it yet.
++         *
++         * FIXME: Need to revisit this moment if such fix doesn't
++         * break anything but since IEEE 695 format is veeery
++         * old I don't expect there are many users left. In worst
++         * case this should only lead to a memory leak.
++         */
++        if (!seg->name)
++            seg->name = nasm_strdup(name);
++
+         if (seg->use32)
+             *bits = 32;
+         else
+--
+2.40.0
diff --git a/meta/recipes-devtools/nasm/nasm_2.15.05.bb b/meta/recipes-devtools/nasm/nasm_2.15.05.bb
index bcb7e071d6..aba061f56f 100644
--- a/meta/recipes-devtools/nasm/nasm_2.15.05.bb
+++ b/meta/recipes-devtools/nasm/nasm_2.15.05.bb
@@ -10,6 +10,7 @@ SRC_URI = "http://www.nasm.us/pub/nasm/releasebuilds/${PV}/nasm-${PV}.tar.bz2 \
            file://0002-Add-debug-prefix-map-option.patch \
            file://CVE-2022-44370.patch \
            file://CVE-2022-46457.patch \
+           file://CVE-2020-21528.patch \
            "
 
 SRC_URI[sha256sum] = "3c4b8339e5ab54b1bcb2316101f8985a5da50a3f9e504d43fa6f35668bee2fd0"