tracing/uprobe: Replace strlcpy() with strscpy()

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].
Additionally, it returns the size of the source string, not the
resulting size of the destination string. In an effort to remove strlcpy()
completely[2], replace strlcpy() here with strscpy().

The negative return value is already handled by this code so no new
handling is needed here.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1]
Link: https://github.com/KSPP/linux/issues/89 [2]
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: linux-trace-kernel@vger.kernel.org
Acked-by: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Link: https://lore.kernel.org/r/20231130205607.work.463-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
This commit is contained in:
Kees Cook 2023-11-30 12:56:08 -08:00
parent b5e3f86a47
commit 8a3750ecf8

View File

@ -151,7 +151,7 @@ fetch_store_string(unsigned long addr, void *dest, void *base)
return -ENOMEM;
if (addr == FETCH_TOKEN_COMM)
ret = strlcpy(dst, current->comm, maxlen);
ret = strscpy(dst, current->comm, maxlen);
else
ret = strncpy_from_user(dst, src, maxlen);
if (ret >= 0) {