From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Kees Cook <keescook@chromium.org>,
Eric Biggers <ebiggers@kernel.org>
Cc: linux-hardening@vger.kernel.org,
Azeem Shaikh <azeemshaikh38@gmail.com>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: [PATCH v2] tracing/boot: Replace strlcpy with strscpy
Date: Thu, 15 Jun 2023 18:04:20 +0000 [thread overview]
Message-ID: <20230615180420.400769-1-azeemshaikh38@gmail.com> (raw)
strlcpy() reads the entire source buffer first.
This read may exceed the destination size limit.
This is both inefficient and can lead to linear read
overflows if a source string is not NUL-terminated [1].
In an effort to remove strlcpy() completely [2], replace
strlcpy() here with strscpy().
Direct replacement is safe here since return value of -errno
is used to check for truncation instead of sizeof(dest).
[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy
[2] https://github.com/KSPP/linux/issues/89
Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com>
---
v2:
* Use "< 0" instead of -E2BIG.
v1:
* https://lore.kernel.org/all/20230613004125.3539934-1-azeemshaikh38@gmail.com/
kernel/trace/trace_boot.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c
index 778200dd8ede..7ccc7a8e155b 100644
--- a/kernel/trace/trace_boot.c
+++ b/kernel/trace/trace_boot.c
@@ -31,7 +31,7 @@ trace_boot_set_instance_options(struct trace_array *tr, struct xbc_node *node)
/* Common ftrace options */
xbc_node_for_each_array_value(node, "options", anode, p) {
- if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+ if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0) {
pr_err("String is too long: %s\n", p);
continue;
}
@@ -87,7 +87,7 @@ trace_boot_enable_events(struct trace_array *tr, struct xbc_node *node)
const char *p;
xbc_node_for_each_array_value(node, "events", anode, p) {
- if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf)) {
+ if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0) {
pr_err("String is too long: %s\n", p);
continue;
}
@@ -486,7 +486,7 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
p = xbc_node_find_value(enode, "filter", NULL);
if (p && *p != '\0') {
- if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+ if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0)
pr_err("filter string is too long: %s\n", p);
else if (apply_event_filter(file, buf) < 0)
pr_err("Failed to apply filter: %s\n", buf);
@@ -494,7 +494,7 @@ trace_boot_init_one_event(struct trace_array *tr, struct xbc_node *gnode,
if (IS_ENABLED(CONFIG_HIST_TRIGGERS)) {
xbc_node_for_each_array_value(enode, "actions", anode, p) {
- if (strlcpy(buf, p, ARRAY_SIZE(buf)) >= ARRAY_SIZE(buf))
+ if (strscpy(buf, p, ARRAY_SIZE(buf)) < 0)
pr_err("action string is too long: %s\n", p);
else if (trigger_process_regex(file, buf) < 0)
pr_err("Failed to apply an action: %s\n", p);
--
2.41.0.162.gfafddb0af9-goog
next reply other threads:[~2023-06-15 18:04 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-15 18:04 Azeem Shaikh [this message]
2023-06-18 22:30 ` [PATCH v2] tracing/boot: Replace strlcpy with strscpy Masami Hiramatsu
2023-06-20 20:28 ` Kees Cook
2023-06-20 20:33 ` Steven Rostedt
2023-06-20 20:35 ` Kees Cook
2023-07-04 13:42 ` Steven Rostedt
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