From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 18DFD2D8364; Mon, 13 Apr 2026 16:34:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776098079; cv=none; b=B2bDUq4q/uYcV7FNp5aAF1u47PZ4juuJWs9SdiZ5FbzvhsA5r3u9BiA8QZgOc+AeemZh16gO/5BahNydvLEI+96WjvK6/inge9XcvIA7DHEH8hXk0iWJx4B4E81qzSnqFBLpKJGw3MrYhzyoqYgeG6TvoVKpryQEZUOZawB1f4U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776098079; c=relaxed/simple; bh=U7c8GqFHG0LmeyeTYJNLyab8arGPSVOpVL1tfkSHbu0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=sb7Vr7vaxHQcdhJEwW5AmoNYUm7ITCbGwMvcBXnlvwWRVyK7IDsOfbb5fflFMffBHvSwutks7FVIWtZQPek+5ogtGX06DABP+E4IeZCzh2HMw/fbFwWcuMGq70FrwgATmkR4veF7VDEf0arobf666NjzueuGm4UCtSGF6D9VKio= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=AItejgzX; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="AItejgzX" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A3EFFC2BCAF; Mon, 13 Apr 2026 16:34:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1776098079; bh=U7c8GqFHG0LmeyeTYJNLyab8arGPSVOpVL1tfkSHbu0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AItejgzXaNKSR6K5V7PZskqVdsQ4Vr9UlLwmc9ZQoYzbX2MQgW/oEj9Qi0gNJ5UNo rBmsYUAWVXEuMpDekWJ/Xkw5SXidhH5nXQGUfHah8qf1vB8/yruW4dUBQCUy8UteTp fswovk+s3f/Bdgw7qx/i3DWCZTe81dyR3KiQhY1U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Arnd Bergmann , stable@kernel.org Subject: [PATCH 5.15 368/570] s390/syscalls: Add spectre boundary for syscall dispatch table Date: Mon, 13 Apr 2026 17:58:19 +0200 Message-ID: <20260413155844.265862356@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260413155830.386096114@linuxfoundation.org> References: <20260413155830.386096114@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Greg Kroah-Hartman commit 48b8814e25d073dd84daf990a879a820bad2bcbd upstream. The s390 syscall number is directly controlled by userspace, but does not have an array_index_nospec() boundary to prevent access past the syscall function pointer tables. Cc: Heiko Carstens Cc: Vasily Gorbik Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Sven Schnelle Cc: Arnd Bergmann Fixes: 56e62a737028 ("s390: convert to generic entry") Cc: stable@kernel.org Assisted-by: gkh_clanker_2000 Signed-off-by: Greg Kroah-Hartman Reviewed-by: Vasily Gorbik Link: https://lore.kernel.org/r/2026032404-sterling-swoosh-43e6@gregkh Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/syscall.c | 2 ++ 1 file changed, 2 insertions(+) --- a/arch/s390/kernel/syscall.c +++ b/arch/s390/kernel/syscall.c @@ -13,6 +13,7 @@ */ #include +#include #include #include #include @@ -141,6 +142,7 @@ static void do_syscall(struct pt_regs *r if (likely(nr >= NR_syscalls)) goto out; do { + nr = array_index_nospec(nr, NR_syscalls); regs->gprs[2] = current->thread.sys_call_table[nr](regs); } while (test_and_clear_pt_regs_flag(regs, PIF_EXECVE_PGSTE_RESTART)); out: