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 113591C5799; Sat, 12 Sep 2026 18:57:51 +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=1789239472; cv=none; b=WTp7XSKxLQFne7I1GzRmBaavNnFVFEJbcaCssbejonfYnNDgyCIdhf+rcgRFXrNLJ4WoNNKh3ePsVCi/Q67OmjEq5ZWfQqdJgbvk+8PtV4tMWTMo+eC3lGdHwIf15vJdaZc+A0oZM61+3thnNIbDNb4jAL74rFwpbFaVfIwz304= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789239472; c=relaxed/simple; bh=V42hUA7Djq23040evskazARU/CdIdOoDTAi569vXHVY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=qCKCbQvegknzf5sb78qTrnPqKCJvSrU1fjW5Y15uUfo5PCFVDdYDk9/h+b5E1Cx5JfNA2OQJgDqKzcyQO4+iB3eI1QWzv6AOPFcjvxWW2FfYC8ecyxF0a4CXSxaaxz9Awrih/n/6px9Xk8k9diyLAxDCz5xGIeIgyQw5cYRrvgc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Zva1DrPQ; 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="Zva1DrPQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 185691F000FF; Sat, 12 Sep 2026 18:57:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789239471; bh=SOpqHn/ehi6EFME+TBJbYIS0aQckXTid3LYGeomQoZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Zva1DrPQf/DsP2DFGP+I1UUG5aoelCloT9b6GjWZKRsVx5yZTL4CB9kGcWLc8i3tB VuUtLVFahac4JUI6FsP34vc+MDZY3+RRrtYt9kAyNX5/DrOnu6RWBYOlEcq/H39PBg UEGDtYz9x1G/8yMGOj61ihKAIx2clN15ancTi/I4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Philippe=20Mathieu-Daud=C3=A9?= , Thomas Bogendoerfer , Sasha Levin Subject: [PATCH 5.15 669/935] MIPS: ptrace: Fix syscall skipping via PTRACE_SYSCALL Date: Sat, 12 Sep 2026 09:01:39 +0200 Message-ID: <20260912065542.186757406@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@linuxfoundation.org> User-Agent: quilt/0.69 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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Thomas Bogendoerfer [ Upstream commit 5475c03fa25f31cfd5f8c7e552f8d10347bbaad9 ] If tracer wanted to skip a syscall return value was always overwritten with -ENOSYS. Fix this by checking against original syscall number and only return -ENOSYS, if it is negative. Fixes: b6318a903d06 ("MIPS/ptrace: Pick up ptrace/seccomp changed syscalls") Reviewed-by: Philippe Mathieu-Daudé Signed-off-by: Thomas Bogendoerfer Signed-off-by: Sasha Levin --- arch/mips/kernel/ptrace.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/arch/mips/kernel/ptrace.c b/arch/mips/kernel/ptrace.c index dd454b429ff73..d051d351e5a01 100644 --- a/arch/mips/kernel/ptrace.c +++ b/arch/mips/kernel/ptrace.c @@ -1312,8 +1312,12 @@ long arch_ptrace(struct task_struct *child, long request, */ asmlinkage long syscall_trace_enter(struct pt_regs *regs) { + long syscall; + user_exit(); + syscall = current_thread_info()->syscall; + if (test_thread_flag(TIF_SYSCALL_TRACE)) { if (tracehook_report_syscall_entry(regs)) return -1; @@ -1349,7 +1353,7 @@ asmlinkage long syscall_trace_enter(struct pt_regs *regs) * Negative syscall numbers are mistaken for rejected syscalls, but * won't have had the return value set appropriately, so we do so now. */ - if (current_thread_info()->syscall < 0) + if (syscall < 0) syscall_set_return_value(current, regs, -ENOSYS, 0); return current_thread_info()->syscall; } -- 2.53.0