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 547A73DFC6D for ; Mon, 5 Oct 2026 21:24:01 +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=1791235442; cv=none; b=SRTxDwXZwR4dDv4wDtLEG+Z5oNRJ/TAdx2BD5IIO0Z5Z6F6+vR+rmmfA+v9UcqQRMck+Es3/Vq6k877Vm9tT2YXqcq/iuJnmrySGg8mNNvmCVq7RpiB2GAOFVVE2k6r8YHQtePjNJ5N9v7zvz8t13qloEauGUkymGIOlP+5veCo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791235442; c=relaxed/simple; bh=60sOS/L6aP0bQbCdUHYjg21bVXdU+MHMtKhGa4axjEw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Lqrfbi2U8t975AuLE/RUesoPqlevd97SXA+oqBZxyAMhjXL9Q80IYQ3DO/t6AfzkN1DnrT+2Yin2y5Cp+fHMMM6S+mbQZgZYFCtwOogmhxpBUUChIPlzL3V0gh/17CWnPPYJqbmXs++LPWTuNNo1NItYEBefNE3bewHKMW1sx38= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=OqJkC/74; 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="OqJkC/74" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C01691F000FF; Mon, 5 Oct 2026 21:23:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1791235440; bh=6igb6aNqYjvedIw0OhYNtHac/CDMGH3QWeYMCRKe1n4=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=OqJkC/74+ItMQb/7FgS4eLAgFcvQJgTxFVT/hl0D/+ZrWKjhyOn1TYoQ4LPGgofST c6e7j78b5Pffb//zub1I04ugJbyX8NNp7B2AQWpTLioBNbfwekYUmzgXrVx18Nz2Bp BYo98LTBgXx+k/2mDZVwU4OZYqA2GSRA5l/n9qXDaHulfwQpBkE8KLYUh7mdxHpxm8 SnJc+aOOA8oP4ZZWOWKPCSiuhKRVsGGldetf4SVOYKuB/9cty9iDuoJlrUZcFpgcbW Bl6lfXwBJwBIxsFTfx4Jr6bjZg2Jf/zWFTTxkoL5nPc/2YW9j8+TlM/v9+fE1i+LS5 17aBnWPC+LstQ== From: Sasha Levin To: stable@vger.kernel.org Cc: Dapeng Mi , "Peter Zijlstra (Intel)" , Sasha Levin Subject: [PATCH 7.2.y 1/2] perf/core: Check kernel access when kernel callchains are requested Date: Mon, 5 Oct 2026 17:23:56 -0400 Message-ID: <20261005212346.3373480-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026100516-douche-preview-30a6@gregkh> References: <2026100516-douche-preview-30a6@gregkh> 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 8a7fcb902a9f7..3c3166d50ec7b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -13882,7 +13882,9 @@ 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