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 7C5DD3F99EA; Tue, 31 Mar 2026 16:27:52 +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=1774974472; cv=none; b=hXjQQ2anvX9mISQFR9QrJy6wafPnKmsdSmbpkZ5vf5TleeMjh8k5PoZhLxhizIz0+6f/VKu45fRKpLyZrEmLlsyeflzLnFAnzxwOQ9cGT8BJNsYXpAeqwIidHvdinhCsDzr4KPcTD8v5Tt7XtUUytU2tl0ZEyXrc2Y0ILfF1PLk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774974472; c=relaxed/simple; bh=d+frPPbXz08G46PbZQ0jL447GQK1gr6EXjAEHW7IzW4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=JGEyCjFs9a9yfZOfbUXsXyO5GWKgpz0hurN4NyOyU022fqbA/VMi6fap+c2fXKYry3RzsFvJzlBNWlfmmn4/z8yyXfCObcqwxG4FTZhYjKn/Be7G+pPGscOK/1RuXQuGy1oPWOSJxM9DEhbMGI8gjqjyIxZySdBJnbUWoaQQlW4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YnBHCK/X; 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="YnBHCK/X" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 13DE5C19423; Tue, 31 Mar 2026 16:27:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774974472; bh=d+frPPbXz08G46PbZQ0jL447GQK1gr6EXjAEHW7IzW4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YnBHCK/X38SA/bnbib92U9gEp/Bm9zogqlqGJbzNQbRqAK1bGMcOLjAg9CWTjYNNP 3fphd+g8vQ4bGIrQYhQGSjBv1VV5Yftut3Bf8hSSJHI3wdRq5rHKhEuZ47ONz4hKR6 SPiBftqiVpKff36Yv+pz9gHaxqecAlfUIVw0TMZw= 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 6.6 098/175] s390/syscalls: Add spectre boundary for syscall dispatch table Date: Tue, 31 Mar 2026 18:21:22 +0200 Message-ID: <20260331161733.380369913@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161729.779738837@linuxfoundation.org> References: <20260331161729.779738837@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 6.6-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: