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 297E71271E7; Mon, 18 Dec 2023 12:47:09 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HouKyTvR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3E2FC433C7; Mon, 18 Dec 2023 12:47:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1702903629; bh=f0ghBydy8x/MWPocuwrQuG8p2pWECMOQwhemDRLW2Ew=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HouKyTvRxj5mgYnsl10h9DvCmDkXg2zPW3xtjrpMAgrd/MNrqU/NE0DgECINXdnvU P65lSZW26aJiVuT0l9xxJge41qYt104V0db967BfwAXPu25LhOK8uDmu/He0rWIAj9 mL9dsyK61GZASKNDKxy3mGa2+vQDukz0JwVjpJpJO2R7ITLa32Eizg3OJS63OuxGlF RypNKpEwLO8+etZ34Zf398+UFepH+HIleLb6V1iZjzjC21Lw+E9myYRVmyr0ZOTWvB o2o6vVzP8ZIZR/O8RL/MElHALdRdPK5eeX6j4GfoQodn6aIqqa3JLGtBmlHazQqNnq P9Eiz+esuQ8uA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Steven Rostedt (Google)" , Mark Rutland , Mathieu Desnoyers , Masami Hiramatsu , Sasha Levin , linux-trace-kernel@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 6/7] tracing: Add size check when printing trace_marker output Date: Mon, 18 Dec 2023 07:46:51 -0500 Message-ID: <20231218124656.1381949-6-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20231218124656.1381949-1-sashal@kernel.org> References: <20231218124656.1381949-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.4.264 Content-Transfer-Encoding: 8bit From: "Steven Rostedt (Google)" [ Upstream commit 60be76eeabb3d83858cc6577fc65c7d0f36ffd42 ] If for some reason the trace_marker write does not have a nul byte for the string, it will overflow the print: trace_seq_printf(s, ": %s", field->buf); The field->buf could be missing the nul byte. To prevent overflow, add the max size that the buf can be by using the event size and the field location. int max = iter->ent_size - offsetof(struct print_entry, buf); trace_seq_printf(s, ": %*.s", max, field->buf); Link: https://lore.kernel.org/linux-trace-kernel/20231212084444.4619b8ce@gandalf.local.home Cc: Mark Rutland Cc: Mathieu Desnoyers Reviewed-by: Masami Hiramatsu (Google) Signed-off-by: Steven Rostedt (Google) Signed-off-by: Sasha Levin --- kernel/trace/trace_output.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index b194dd1c8420f..9ffe54ff3edb2 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1291,11 +1291,12 @@ static enum print_line_t trace_print_print(struct trace_iterator *iter, { struct print_entry *field; struct trace_seq *s = &iter->seq; + int max = iter->ent_size - offsetof(struct print_entry, buf); trace_assign_type(field, iter->ent); seq_print_ip_sym(s, field->ip, flags); - trace_seq_printf(s, ": %s", field->buf); + trace_seq_printf(s, ": %.*s", max, field->buf); return trace_handle_return(s); } @@ -1304,10 +1305,11 @@ static enum print_line_t trace_print_raw(struct trace_iterator *iter, int flags, struct trace_event *event) { struct print_entry *field; + int max = iter->ent_size - offsetof(struct print_entry, buf); trace_assign_type(field, iter->ent); - trace_seq_printf(&iter->seq, "# %lx %s", field->ip, field->buf); + trace_seq_printf(&iter->seq, "# %lx %.*s", field->ip, max, field->buf); return trace_handle_return(&iter->seq); } -- 2.43.0