mit-krb5: Workaround for MSAN not handling getrandom
MSAN does not track memory writes by getrandom. Thus, anything that uses
the random numbers causes Use-of-uninitialized-value errors. This is a
false positive. As a workaround, set buffer to 0 before calling
getrandom.
I've verified that the random bytes are indeed written, just in case.
BUG=chromium:988025
TEST=config_validator_fuzzer doesn't report bug anymore
Change-Id: Id3048848e82bbab31d55e92aaa228ce8e4c2ead1
Reviewed-on: https://chromium-review.googlesource.com/1757923
Tested-by: Lutz Justen <ljusten@chromium.org>
Commit-Ready: Lutz Justen <ljusten@chromium.org>
Legacy-Commit-Queue: Commit Bot <commit-bot@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Reviewed-by: Lutz Justen <ljusten@chromium.org>
diff --git a/app-crypt/mit-krb5/files/mit-krb5-1.16_uninitialized_memory_workaround.patch b/app-crypt/mit-krb5/files/mit-krb5-1.16_uninitialized_memory_workaround.patch
new file mode 100644
index 0000000..0191d01
--- /dev/null
+++ b/app-crypt/mit-krb5/files/mit-krb5-1.16_uninitialized_memory_workaround.patch
@@ -0,0 +1,16 @@
+Workaround for https://crbug.com/988025.
+
+--- src/lib/crypto/krb/prng.c
++++ src/lib/crypto/krb/prng.c
+@@ -102,6 +102,11 @@ k5_get_os_entropy(unsigned char *buf, size_t len, int strong)
+ #if defined(__linux__) && defined(SYS_getrandom)
+ int r;
+
++ // https://crbug.com/988025: Workaround for uninitialized memory errors
++ // under MSAN. Memory sanitizer does not track memory writes by
++ // SYS_getrandom calls.
++ memset(buf, 0, len);
++
+ while (len > 0) {
+ /*
+ * Pull from the /dev/urandom pool, but require it to have been seeded.
diff --git a/app-crypt/mit-krb5/mit-krb5-1.16.1-r1.ebuild b/app-crypt/mit-krb5/mit-krb5-1.16.1-r2.ebuild
similarity index 100%
rename from app-crypt/mit-krb5/mit-krb5-1.16.1-r1.ebuild
rename to app-crypt/mit-krb5/mit-krb5-1.16.1-r2.ebuild
diff --git a/app-crypt/mit-krb5/mit-krb5-1.16.1.ebuild b/app-crypt/mit-krb5/mit-krb5-1.16.1.ebuild
index 1708713..b146913 100644
--- a/app-crypt/mit-krb5/mit-krb5-1.16.1.ebuild
+++ b/app-crypt/mit-krb5/mit-krb5-1.16.1.ebuild
@@ -59,6 +59,7 @@
eapply -p2 "${FILESDIR}/${PN}-config_LDFLAGS.patch"
eapply "${FILESDIR}/${PN}-libressl-version-check.patch"
eapply "${FILESDIR}/${PN}-1.16_quoted_string_buffer_overflow.patch"
+ eapply "${FILESDIR}/${PN}-1.16_uninitialized_memory_workaround.patch"
# Make sure we always use the system copies.
rm -rf util/{et,ss,verto}
