lkml.org 
[lkml]   [2023]   [Aug]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v2] kobject: Replace strlcpy with strscpy
Date
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:
* Updated error message to remove @len which is errno now.

v1:
* https://lore.kernel.org/all/20230703180528.3709258-1-azeemshaikh38@gmail.com/

lib/kobject_uevent.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index 7c44b7ae4c5c..323127e444d4 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -254,10 +254,10 @@ static int init_uevent_argv(struct kobj_uevent_env *env, const char *subsystem)
int buffer_size = sizeof(env->buf) - env->buflen;
int len;

- len = strlcpy(&env->buf[env->buflen], subsystem, buffer_size);
- if (len >= buffer_size) {
- pr_warn("init_uevent_argv: buffer size of %d too small, needed %d\n",
- buffer_size, len);
+ len = strscpy(&env->buf[env->buflen], subsystem, buffer_size);
+ if (len < 0) {
+ pr_warn("init_uevent_argv: insufficient buffer space "
+ "(%u left) for %s\n", buffer_size, subsystem);
return -ENOMEM;
}

--
2.42.0.rc2.253.gd59a3bf2b4-goog

\
 
 \ /
  Last update: 2023-08-30 21:23    [W:0.191 / U:0.264 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site