From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 F199B38837C; Wed, 29 Apr 2026 20:14:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777493692; cv=none; b=gBY3m48FA8xYvL/0qjUuvA4C2r5q6TL6Zw8PaDq9wOfYIp710LAn1FqQFY8IHZ2efMlln/kvZyO5ks+Gb50PHn7h3f1y1csnT2R8//BHq/tml3rvtbsmMs8uoY2DtLkhyiKgw2mCjcuN6xtF9uesRQu10PiD7vIyOlNv/qWRwS8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777493692; c=relaxed/simple; bh=T0lhqDY2oFOIHQJjCyF6NbTeUGPfvrf6TV86DHkLx8w=; h=Message-ID:Date:From:To:Cc:Subject:References:MIME-Version: Content-Type; b=X+08LmvBrAMH0L1kpPzXXmGlk9NHRn58ASb7nqBq0JIZYo1Uh79ebwvBE85h6pc1DtA55WsLuphznBbW336OQuMAsVPcLU+m+0AjF41sW5P0KGeYCCgfJGELsLuzA2TtqSYcT6PSMEhkq7NHZeVJGlMtPWUuLyoWH9gTVzzn2qI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QHjvP4AO; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QHjvP4AO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D3F36C2BCC7; Wed, 29 Apr 2026 20:14:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777493691; bh=T0lhqDY2oFOIHQJjCyF6NbTeUGPfvrf6TV86DHkLx8w=; h=Date:From:To:Cc:Subject:References:From; b=QHjvP4AOH4ini0PNhWx+AzvlcKer6GmdK2gf8GtUCXOWAP8S0ROO/8tJm+OmpIfUF Qh7zj4HBddw6DjzuZyYk5VfQMQ/KL1NMIyXMad4rJo1m0uc+gfvf/hzH/rShj0ZjJP gnwWATZuS7N5Wo+kD3rqly39rXBadjly+8Gtrx61QNNIwxq5JiFbNWFMk3O0qk29/2 IN/CRQeZ1dv4U4s9LLSul9dvxncMpbWlAuItp9+Nd7ejyVsDluE1Ww53REvH1pZcJm UCWfAfFRkbC3AyR8QPC5Hkvu5TMRvTu7b0jU8O/azvj0Dw+ohtucTf7FmRDSqiga1U R109KRMyeMMdw== Received: from rostedt by gandalf with local (Exim 4.99.1) (envelope-from ) id 1wIBJN-00000003m6I-2kQN; Wed, 29 Apr 2026 16:15:09 -0400 Message-ID: <20260429201509.513685251@kernel.org> User-Agent: quilt/0.69 Date: Wed, 29 Apr 2026 16:14:56 -0400 From: Steven Rostedt To: linux-kernel@vger.kernel.org Cc: Masami Hiramatsu , Mark Rutland , Mathieu Desnoyers , Andrew Morton , stable@vger.kernel.org Subject: [for-linus][PATCH 3/3] tracing/probes: Limit size of event probe to 3K References: <20260429201453.449214720@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 From: Steven Rostedt There currently isn't a max limit an event probe can be. One could make an event greater than PAGE_SIZE, which makes the event useless because if it's bigger than the max event that can be recorded into the ring buffer, then it will never be recorded. A event probe should never need to be greater than 3K, so make that the max size. As long as the max is less than the max that can be recorded onto the ring buffer, it should be fine. Cc: stable@vger.kernel.org Cc: Mathieu Desnoyers Acked-by: Masami Hiramatsu (Google) Fixes: 93ccae7a22274 ("tracing/kprobes: Support basic types on dynamic events") Link: https://patch.msgid.link/20260428122302.706610ba@gandalf.local.home Signed-off-by: Steven Rostedt --- kernel/trace/trace_probe.c | 6 ++++++ kernel/trace/trace_probe.h | 4 +++- 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_probe.c b/kernel/trace/trace_probe.c index e1c73065dae5..e0d3a0da26af 100644 --- a/kernel/trace/trace_probe.c +++ b/kernel/trace/trace_probe.c @@ -1523,6 +1523,12 @@ static int traceprobe_parse_probe_arg_body(const char *argv, ssize_t *size, parg->offset = *size; *size += parg->type->size * (parg->count ?: 1); + if (*size > MAX_PROBE_EVENT_SIZE) { + ret = -E2BIG; + trace_probe_log_err(ctx->offset, EVENT_TOO_BIG); + goto fail; + } + if (parg->count) { len = strlen(parg->type->fmttype) + 6; parg->fmt = kmalloc(len, GFP_KERNEL); diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 9fc56c937130..262d8707a3df 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -38,6 +38,7 @@ #define MAX_BTF_ARGS_LEN 128 #define MAX_DENTRY_ARGS_LEN 256 #define MAX_STRING_SIZE PATH_MAX +#define MAX_PROBE_EVENT_SIZE 3072 /* Reserved field names */ #define FIELD_STRING_IP "__probe_ip" @@ -561,7 +562,8 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call, C(BAD_TYPE4STR, "This type does not fit for string."),\ C(NEED_STRING_TYPE, "$comm and immediate-string only accepts string type"),\ C(TOO_MANY_ARGS, "Too many arguments are specified"), \ - C(TOO_MANY_EARGS, "Too many entry arguments specified"), + C(TOO_MANY_EARGS, "Too many entry arguments specified"), \ + C(EVENT_TOO_BIG, "Event too big (too many fields?)"), #undef C #define C(a, b) TP_ERR_##a -- 2.53.0