From 1af424b15401d2be789c4dc2279889514e7c5c94 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Tue, 21 Oct 2025 20:34:05 -0700 Subject: [PATCH] lib/crypto: poly1305: Restore dependency of arch code on !KMSAN Restore the dependency of the architecture-optimized Poly1305 code on !KMSAN. It was dropped by commit b646b782e522 ("lib/crypto: poly1305: Consolidate into single module"). Unlike the other hash algorithms in lib/crypto/ (e.g., SHA-512), the way the architecture-optimized Poly1305 code is integrated results in assembly code initializing memory, for several different architectures. Thus, it generates false positive KMSAN warnings. These could be suppressed with kmsan_unpoison_memory(), but it would be needed in quite a few places. For now let's just restore the dependency on !KMSAN. Note: this should have been caught by running poly1305_kunit with CONFIG_KMSAN=y, which I did. However, due to an unrelated KMSAN bug (https://lore.kernel.org/r/20251022030213.GA35717@sol/), KMSAN currently isn't working reliably. Thus, the warning wasn't noticed until later. Fixes: b646b782e522 ("lib/crypto: poly1305: Consolidate into single module") Reported-by: syzbot+01fcd39a0d90cdb0e3df@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/68f6a48f.050a0220.91a22.0452.GAE@google.com/ Reported-by: Pei Xiao Closes: https://lore.kernel.org/r/751b3d80293a6f599bb07770afcef24f623c7da0.1761026343.git.xiaopei01@kylinos.cn/ Reviewed-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20251022033405.64761-1-ebiggers@kernel.org Signed-off-by: Eric Biggers --- lib/crypto/Kconfig | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/crypto/Kconfig b/lib/crypto/Kconfig index eea17e36a22b..8886055e938f 100644 --- a/lib/crypto/Kconfig +++ b/lib/crypto/Kconfig @@ -97,7 +97,7 @@ config CRYPTO_LIB_POLY1305 config CRYPTO_LIB_POLY1305_ARCH bool - depends on CRYPTO_LIB_POLY1305 && !UML + depends on CRYPTO_LIB_POLY1305 && !UML && !KMSAN default y if ARM default y if ARM64 && KERNEL_MODE_NEON default y if MIPS