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 A023E280012; Tue, 27 May 2025 17:26:26 +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=1748366786; cv=none; b=dFk84TWBLMVXmgrOnQl4lK1E2ldiGGhzjpWjhqTtU/qoYNhUUtYBJMvUPQ8caxcLu7NQEuOVbB0r5KAyFjIFa8ZommpAKVjmNsx+Zz7PGZHAlCmKIMmTCu3Zp3QF8bAPH9xSGjW9ZqN7wbWK7x2hpGZOZ7cyTKDJaRC65/jiibU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748366786; c=relaxed/simple; bh=iYfKhxp3QvZCX9cVfvdwsWHSgKY1M89GU4X9w2jrrJs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hVBv2/NLsf4TeQAZ7QPIx68XqtdwHrzzWt7Hr5sEsFz70z2oNSn1UbRHevgoXSl98vkwoMIihJTNlKQRrE2SxhMArTvprd5A8zQiB0+antih84l29k72FImHkg1k3yj1PQE+B4K0Qiupb1qOE0VaCqRCGlib3vpIfGW/4fP7xGU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=cqlvgPdJ; 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="cqlvgPdJ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 26C8DC4CEE9; Tue, 27 May 2025 17:26:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1748366786; bh=iYfKhxp3QvZCX9cVfvdwsWHSgKY1M89GU4X9w2jrrJs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cqlvgPdJ1N27SiYBwlvfe4NqyikealggRNipwf9TftCcDJMAmu9CiWf1iNQ4UZKAm 2OkYCt69cRKEMz7L/3+F15LLnlwSeRmkwDUYmxO+HdGRDsNq6f9R1gP3jik4xyNAr5 OpiCjpSvKWpa9ZClNhVgudqg93yAHH6E35FOFn1U= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Benjamin Berg , Johannes Berg , Sasha Levin Subject: [PATCH 6.14 150/783] um: Store full CSGSFS and SS register from mcontext Date: Tue, 27 May 2025 18:19:07 +0200 Message-ID: <20250527162519.269631487@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250527162513.035720581@linuxfoundation.org> References: <20250527162513.035720581@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Benjamin Berg [ Upstream commit cef721e0d53d2b64f2ba177c63a0dfdd7c0daf17 ] Doing this allows using registers as retrieved from an mcontext to be pushed to a process using PTRACE_SETREGS. It is not entirely clear to me why CSGSFS was masked. Doing so creates issues when using the mcontext as process state in seccomp and simply copying the register appears to work perfectly fine for ptrace. Signed-off-by: Benjamin Berg Link: https://patch.msgid.link/20250224181827.647129-2-benjamin@sipsolutions.net Signed-off-by: Johannes Berg Signed-off-by: Sasha Levin --- arch/x86/um/os-Linux/mcontext.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/arch/x86/um/os-Linux/mcontext.c b/arch/x86/um/os-Linux/mcontext.c index e80ab7d281177..1b0d95328b2c7 100644 --- a/arch/x86/um/os-Linux/mcontext.c +++ b/arch/x86/um/os-Linux/mcontext.c @@ -27,7 +27,6 @@ void get_regs_from_mc(struct uml_pt_regs *regs, mcontext_t *mc) COPY(RIP); COPY2(EFLAGS, EFL); COPY2(CS, CSGSFS); - regs->gp[CS / sizeof(unsigned long)] &= 0xffff; - regs->gp[CS / sizeof(unsigned long)] |= 3; + regs->gp[SS / sizeof(unsigned long)] = mc->gregs[REG_CSGSFS] >> 48; #endif } -- 2.39.5