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 2F2984F7CCA; Tue, 13 Oct 2026 12:25:14 +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=1791894316; cv=none; b=OtRppotE2pPq38uI10BPalUJtAivl7WAEqAQnKercexDhjDR957ZCWLa5/7nj3Cnk2iD8EOZr0SdFAMg/IF3HJl2IH1LSkUNyai88yV/b78DrT74dvvdlO53c5a3K2ZmRCXCuiCzvBMctZhiOjC80gxMVKQ16xUvZmUZgRrLi4c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1791894316; c=relaxed/simple; bh=L9p0gEkSCUI0v81lx/cL3+zs/eihxOPu7g5BWIA8DhI=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=GqTbn8k1xjBHz6HZUa2lVMaE+T64c/AC7VHxywl9dWUJQ3exrEak1tLQDBvIGRF2SmPQAD72Ulbjzcx2wE6JhOVJ3WfmK6YUA3cyTXrTSAPnobLaVA+SFD1XRusDziG61KA3c4qXsN9KPaaX4g00tpOAcCuqCLdLczEv+mgQASo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qEOg2kDv; 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="qEOg2kDv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 365921F000FF; Tue, 13 Oct 2026 12:25:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1791894314; bh=g1EwsYlawYRmNZ/dMQ/XGB1Ruey4+3OPeYHEASwbK4M=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=qEOg2kDvA5f64nkKKj9fYADeRIInXJQmktNsiiEFtQ8vH+MbtU2QtzxeIHLWpH2Va GP+BeYkV/7VqzhplRMETUBQ4bzB7plYgHDWWNK80xvsIQs4RYeoqHRza6AiPxt/eS4 Gb2jQ5uGJHZq/vLJkO9QdTI52aSuNaVOK3sCo40A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, sashiko-bot@kernel.org, Vincent Donnefort , Steven Rostedt , Sasha Levin Subject: [PATCH 6.18 518/621] ring-buffer: Add checking nr_subbufs to persistent ring buffer validation Date: Tue, 13 Oct 2026 13:38:33 +0200 Message-ID: <20261013112933.116376153@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261013112920.855194808@linuxfoundation.org> References: <20261013112920.855194808@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-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Steven Rostedt [ Upstream commit 6c001a62c34f13fe1c6a24304c289b387d9e697d ] Sashiko reported that the code was using meta->nr_subbufs without making sure that it matched the nr_pages + 1 on data that was assuming the two were the same. Add a check to the persistent ring buffer validation code to make sure that the saved nr_subbufs matches what we expect. Link: https://patch.msgid.link/20260903132728.7fb27d34@gandalf.local.home Fixes: f5b95f1fa2ef3 ("ring-buffer: Validate the persistent meta data subbuf array") Reported-by: sashiko-bot@kernel.org Closes: https://lore.kernel.org/all/20260901164836.D962D1F000E9@smtp.kernel.org/ Reviewed-by: Vincent Donnefort Signed-off-by: Steven Rostedt Signed-off-by: Sasha Levin --- kernel/trace/ring_buffer.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c index eed5c45b86ae6..c6d3730eb6f3a 100644 --- a/kernel/trace/ring_buffer.c +++ b/kernel/trace/ring_buffer.c @@ -1854,6 +1854,11 @@ static bool rb_cpu_meta_valid(struct ring_buffer_cpu_meta *meta, int cpu, return false; } + if (meta->nr_subbufs != nr_pages + 1) { + pr_info("Ring buffer boot meta [%d] invalid nr_subbufs\n", cpu); + return false; + } + buffers_start = meta->first_buffer; buffers_end = meta->first_buffer + (subbuf_size * meta->nr_subbufs); -- 2.53.0