Messages in this thread Patch in this message | | | From | Azeem Shaikh <> | Subject | [PATCH v4] kobject: Replace strlcpy with strscpy | Date | Thu, 31 Aug 2023 14:01:04 +0000 |
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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> --- v4: * Fixes errors reported by checkpatch.pl
v3: * Fixed weird indentation. * https://lore.kernel.org/all/20230830202021.4134348-1-azeemshaikh38@gmail.com/
v2: * Updated error message to remove @len which is errno now. * https://lore.kernel.org/all/20230830150136.3798414-1-azeemshaikh38@gmail.com/
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..fb9a2f06dd1e 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("%s: insufficient buffer space (%u left) for %s\n", + __func__, buffer_size, subsystem); return -ENOMEM; }
-- 2.42.0.283.g2d96d420d3-goog
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