From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 4C9A326B973; Thu, 28 May 2026 20:01:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779998494; cv=none; b=harQ95rYDYQ9IO7asy9znDszc7CBm42/B/EOwUP6ZJxB/vrEsRAIgI4fubGTjKHU7fjVdflPQyYfEvNYKouPYLCJQC5vNaljrk5jS5vHcXQhIbLi69hCU2tjN8uU06xheofCvXxd2zqDU8JRbR/VzyavxbbUs2wqE9wJvK5iAsU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779998494; c=relaxed/simple; bh=gvdg7NThHvXcUJt8T/sZ0HDcMWnUeh1Atj/a057K4eM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jaoiVxFRiZLe03NW42yv2ZeZ8cQLvsIEQe9EcblRQa5A2hkgGVpD1h9cEUr4xnq/reYcRV1+XawvZsI7DpOeQe4SxRpZefw0IwARSd/TxI3HWokdiUBwpm00VCaBZqRoAF89bWEy+K2yo8lILx/NFl5UzK93CmalTNrm3XIotmE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BbakMQhr; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="BbakMQhr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id AA9061F000E9; Thu, 28 May 2026 20:01:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779998493; bh=z0Ncv8Pv93EjVrG4FJCWOVWHPjEDEXJvp4QOKtSzJBo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BbakMQhrrHDqOpKiQQDqvjcHmhRVoFWr5kKlPa/tYx2mjZj6EReu1N3+JoskgAGt+ 3RiVvaocYEhpYKCIdVYxplYs1KfqUF9xPUtH1FxTqQ+eTrRM6xqXfpfyA8lkYQmN1J ew3uvgJrZ+9Uh7Ws4ZGDbV0WsfLuB0+wQQMr1ty4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Michael Neuling , Paul Walmsley , Sasha Levin Subject: [PATCH 7.0 192/461] riscv: Fix register corruption from uninitialized cregs on error Date: Thu, 28 May 2026 21:45:21 +0200 Message-ID: <20260528194652.637904738@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260528194646.819809818@linuxfoundation.org> References: <20260528194646.819809818@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 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Michael Neuling [ Upstream commit 6ebcbb53fc9bc30843054ed99fd60b8e542628f4 ] compat_riscv_gpr_set() calls cregs_to_regs() unconditionally, even when user_regset_copyin() fails. Since cregs is an uninitialized stack variable, a copyin failure causes uninitialized stack data to be written into the target task's pt_regs, corrupting its register state and potentially leaking kernel stack contents. compat_restore_sigcontext() has the same issue: it calls cregs_to_regs() even when __copy_from_user() fails, leading to the same corruption of the signal-returning task's register state on error. Only call cregs_to_regs() when the user copy succeeds. Fixes: 4608c159594f ("riscv: compat: ptrace: Add compat_arch_ptrace implement") Fixes: 7383ee05314b ("riscv: compat: signal: Add rt_frame implementation") Signed-off-by: Michael Neuling Assisted-by: Cursor:claude-4.6-opus-high-thinking Link: https://patch.msgid.link/20260501062320.2339562-1-mikey@neuling.org Signed-off-by: Paul Walmsley Signed-off-by: Sasha Levin --- arch/riscv/kernel/compat_signal.c | 2 ++ arch/riscv/kernel/ptrace.c | 4 ++-- 2 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/riscv/kernel/compat_signal.c b/arch/riscv/kernel/compat_signal.c index 6ec4e34255a9a..cf3eb33a11e46 100644 --- a/arch/riscv/kernel/compat_signal.c +++ b/arch/riscv/kernel/compat_signal.c @@ -107,6 +107,8 @@ static long compat_restore_sigcontext(struct pt_regs *regs, /* sc_regs is structured the same as the start of pt_regs */ err = __copy_from_user(&cregs, &sc->sc_regs, sizeof(sc->sc_regs)); + if (unlikely(err)) + return err; cregs_to_regs(&cregs, regs); diff --git a/arch/riscv/kernel/ptrace.c b/arch/riscv/kernel/ptrace.c index 93de2e7a30747..793bcee461828 100644 --- a/arch/riscv/kernel/ptrace.c +++ b/arch/riscv/kernel/ptrace.c @@ -577,8 +577,8 @@ static int compat_riscv_gpr_set(struct task_struct *target, struct compat_user_regs_struct cregs; ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &cregs, 0, -1); - - cregs_to_regs(&cregs, task_pt_regs(target)); + if (!ret) + cregs_to_regs(&cregs, task_pt_regs(target)); return ret; } -- 2.53.0