From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792859138; b=3juwrIOfHuJ0lua3EYi/xRtv5emRKHXiebKTqSz+gT+SBkxtkfChx9o5ht5AubGxXljH mK9QUhogBJUND7oqy8Z371aOpvzwIdhFgmONzefx1SK0mQaaqtSnjVhr4iZEWQDhJnCTN vgnp/2m+J7w2rJ1qO9NWEaa0ug6dIzzYozKbjrAScWHLibMcqhmfsGyYvNvHMQzuOt+lq g3mvScKJl6thRypOrsnnmYbbqKvXz++8d1jpfnOq2ev05xH/tQ6R7lnEIqVQb03x20P3S +C6LowvE8rf2C8aeiFvEQfCB0eiuh4k499Dt/9m47tiBVSPPqfFJINmULM7kki5kIAw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792859138; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:MIME-Version:Content-Type: Content-Transfer-Encoding; bh=b1zo6Tke0W4D3cqOhBnOl0B3urwoXtxoWUxyN83ZYO0=; b=VOWDjLIZoSKU/R1SIisVWVpOrMw86mIfdNGqHDDk4eDwQeS3kSjzshMgL2k6zD5tBB+7 O3K69pMiCTAADlKvdo7tvPIC34ZCsssMzaEaaSceIWA3kjPwJ5sDFMpHqUo4GMoZjDahX 7lKwNm8QXAOXPXSlKMG42VaipIeQdeadbc3UGxcD9yCxq0NZfNxv3CAW0z1GTq+UL2W8T ZUR5DAc0pr62bR1rDIBSsmgGHVAKAqSKz1nDpwkdCuW7oVIm11crlz2KWbPm/O2byv02k PKAHIj5g6LOeOkyjnAhTOF68NrzY9tLgQOjy5AUwGFuuacGoDrQu+uj4fk9pYzH4uvw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=NRdtLukb; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AA62C606A323; Sat, 24 Oct 2026 16:25:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=NRdtLukb Received: by smtp.kernel.org (Postfix) with ESMTPSA id 972AF1F031E2; Sat, 24 Oct 2026 16:25:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1792859137; bh=b1zo6Tke0W4D3cqOhBnOl0B3urwoXtxoWUxyN83ZYO0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=NRdtLukbE74jRSaFFbXpgVyZCQJTQ2+mxUmxriDxyKAob9Mrw6AMZMa83iP9/Ny1L Ch0vcxO/Gm7fmnj0FXkuYyISUuVAe6WKh0E3S4/9Jj+BkWBZA2zP1gDO+A7ZeeV9co jb8ttEfFuNWkc5tmivekLHvPJsiqeiT52K3EG/n9bFJ3aOj87EkOFGDCNOLZdmUAkE +5dFD3v5YXvzMqvecTcFSZMVc/zAI+8wy727Zcfg1MQ0Nbnq458i570bjKXFLIF4tx Kng7xSDLSQggYLXPIVB2bNdGjcDNMjNXSQdI6oeUQd/BIFLbf5WSKT+ZXcFxrK1GNm 86CKLrq5GkITg== From: "Masami Hiramatsu (Google)" To: Steven Rostedt , Masami Hiramatsu , Shuah Khan Cc: Mathieu Desnoyers , linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: [PATCH 01/10] tracing/filters: Fix MATCH_END_ONLY regex matching for fixed-size strings Date: Sun, 25 Oct 2026 01:25:33 +0900 Message-ID: <179285913336.466249.16045710288666912574.stgit@devnote2> X-Mailer: git-send-email 2.43.0 In-Reply-To: <179285912318.466249.7425922682086130057.stgit@devnote2> References: <179285912318.466249.7425922682086130057.stgit@devnote2> User-Agent: StGit/0.19 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit From: Masami Hiramatsu (Google) regex_match_end() calculated string length as "len - 1", assuming @len is the string length including trailing '\0'. However, for fixed-size string fields, filter_pred_string() passes field->size as @len, and for "comm", filter_pred_comm() passes TASK_COMM_LEN as @len. Because @len in these cases represents the buffer capacity rather than the actual length of the string, regex_match_end() tests against the tail of the buffer (typically trailing '\0' padding) rather than the end of the string. Furthermore, if @len is 0 (denoting a dynamic string ending with '\0'), "len - 1" underflows to -1 and never matches. Compute the actual string length using strnlen(str, len) when @len is non-zero, and strlen(str) when @len is zero. Fixes: a3291c14ecf0 ("tracing/filters: Fix MATCH_END_ONLY filter matching") Cc: stable@vger.kernel.org Signed-off-by: Masami Hiramatsu (Google) --- kernel/trace/trace_events_filter.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index 5e74d2dae40a..18ce3ec00d34 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -1075,10 +1075,10 @@ static int regex_match_middle(char *str, struct regex *r, int len) static int regex_match_end(char *str, struct regex *r, int len) { - int strlen = len - 1; + int slen = len ? strnlen(str, len) : strlen(str); - if (strlen >= r->len && - memcmp(str + strlen - r->len, r->pattern, r->len) == 0) + if (slen >= r->len && + memcmp(str + slen - r->len, r->pattern, r->len) == 0) return 1; return 0; }