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 79DEB3AC0D0 for ; Mon, 5 Oct 2026 22:12:45 +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=1791238366; cv=none; b=QpnRlWELjFGX94cR8w4hnRGL+N3HO13k5554o5W1byzf/+1bs+Kd0zrAlpae2DlXJdvPEP02qkOSJ5ETgi5omegv+rnrGZPifjxsqzibhGReUabGjrrNt8V3UvGxhSn4afHE3bbbZSdDzn2LjjEv7rgj5qk91qZJ8MiaPrkAJFs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791238366; c=relaxed/simple; bh=XA9vyd8rXaRSJvtR0v1YPTxnDPOs6LqLzEQ1Css16uQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YQiBFMHcI3yr5GeFRbBm1L/ybCM84ArIguPWAiCaMX8zjuSLnhRR5P7U1prNpdsTBxag+uSQ6UWoNXK7/FYSDG3M9litvxrcDjaI/Iv8/7SKtjrw+4UCpJIQcnr7EqD586RBwdMvgMZYcRY916ZEjq4I8aMjxXCu41EmBKiadO0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=gUxwl0t/; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="gUxwl0t/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DEBCE1F00893; Mon, 5 Oct 2026 22:12:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791238365; bh=w+4RjG0cBsTb8izqz6gdZED/hHJYvgzxLdDjDIXKwZM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gUxwl0t/pRwy2qJDfYOSjl5kxPXgSYkhK/JJ3YFRPyHoDCFhi3zf4u1YYzGg9PkjT 96IpZZ0wNhajk9Vri4Jw6UhmeeXzL+kgs9H6yYO4OJGIXtuOLI/9YmKxETQLjyyfCY /fcMZoA5UOf/F0Q5dkv1btxP0Rm5Uy72dq5xe9xcOpLRr1UM3RDuIkbuFgUhFgzLNW yvCN43G7hazRwHsNfh2H04LCzTe0nJpUNyzRXdVa5bWkv97xsC4H+V5zZ3uMdWK6LS s1LfjR7FnamMp5KH1PuPAfRSNcCfTdC7K1uN7/+y1ZexVuJygBcsf02ViAUfFNZBcC D1ORkPqA+BvGQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Dapeng Mi , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 6.12.y 2/3] perf/core: Check kernel access when kernel callchains are requested Date: Mon, 5 Oct 2026 18:12:38 -0400 Message-ID: <20261005221222.3426405-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261005221222.3426405-1-sashal@kernel.org> References: <2026100517-flask-antiviral-2fbf@gregkh> <20261005221222.3426405-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Dapeng Mi [ Upstream commit a4573a3838ae4fc73b70019cfa1dac9aaea7cc2f ] perf_event_open() currently gates perf_allow_kernel() only on !attr.exclude_kernel. However, users can still request kernel callchain collection with attr.exclude_callchain_kernel == 0 even when attr.exclude_kernel == 1. That still requires kernel profiling privilege, but the existing check does not enforce it. Update the permission check to call perf_allow_kernel() when either kernel sampling is requested or kernel callchains are requested. This keeps permission checks aligned with requested data and prevents unprivileged use of kernel callchain capture. Signed-off-by: Dapeng Mi Signed-off-by: Peter Zijlstra (Intel) Link: https://patch.msgid.link/20260616044654.3468742-9-dapeng1.mi@linux.intel.com Stable-dep-of: 357e8a77a501 ("perf: Require kernel access for text poke events") Signed-off-by: Sasha Levin --- kernel/events/core.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index ddabdc16e3880..3791c84ffe2cf 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -12893,7 +12893,9 @@ SYSCALL_DEFINE5(perf_event_open, if (err) return err; - if (!attr.exclude_kernel) { + if (!attr.exclude_kernel || + ((attr.sample_type & PERF_SAMPLE_CALLCHAIN) && + !attr.exclude_callchain_kernel)) { err = perf_allow_kernel(); if (err) return err; -- 2.53.0