| Message ID | 20230830150136.3798414-1-azeemshaikh38@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | [v2] kobject: Replace strlcpy with strscpy | expand |
> - 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); Please ignore this patch. There's some weird indentation that I noticed here that I'll fix in v3.
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; }
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(-)