From b00839ca4cca8aa9641c121c848a553d6220ce70 Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Wed, 13 Sep 2023 17:13:04 +0000 Subject: ipmi: refactor deprecated strncpy `strncpy` is deprecated for use on NUL-terminated destination strings [1]. In this case, strncpy is being used specifically for its NUL-padding behavior (and has been commented as such). Moreover, the destination string is not required to be NUL-terminated [2]. We can use a more robust and less ambiguous interface in `memcpy_and_pad` which makes the code more readable and even eliminates the need for that comment. Let's also use `strnlen` instead of `strlen()` with an upper-bounds check as this is intrinsically a part of `strnlen`. Also included in this patch is a simple 1:1 change of `strncpy` to `strscpy` for ipmi_ssif.c. If NUL-padding is wanted here as well then we should opt again for `strscpy_pad`. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://lore.kernel.org/all/ZQEADYBl0uZ1nX60@mail.minyard.net/ [2] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Cc: Kees Cook Signed-off-by: Justin Stitt Message-Id: <20230913-strncpy-drivers-char-ipmi-ipmi-v2-1-e3bc0f6e599f@google.com> Signed-off-by: Corey Minyard --- drivers/char/ipmi/ipmi_msghandler.c | 11 +++-------- drivers/char/ipmi/ipmi_ssif.c | 2 +- 2 files changed, 4 insertions(+), 9 deletions(-) (limited to 'drivers/char') diff --git a/drivers/char/ipmi/ipmi_msghandler.c b/drivers/char/ipmi/ipmi_msghandler.c index 186f1fee7534..d6f14279684d 100644 --- a/drivers/char/ipmi/ipmi_msghandler.c +++ b/drivers/char/ipmi/ipmi_msghandler.c @@ -5377,20 +5377,15 @@ static void send_panic_events(struct ipmi_smi *intf, char *str) j = 0; while (*p) { - int size = strlen(p); + int size = strnlen(p, 11); - if (size > 11) - size = 11; data[0] = 0; data[1] = 0; data[2] = 0xf0; /* OEM event without timestamp. */ data[3] = intf->addrinfo[0].address; data[4] = j++; /* sequence # */ - /* - * Always give 11 bytes, so strncpy will fill - * it with zeroes for me. - */ - strncpy(data+5, p, 11); + + memcpy_and_pad(data+5, 11, p, size, '\0'); p += size; ipmi_panic_request_and_wait(intf, &addr, &msg); diff --git a/drivers/char/ipmi/ipmi_ssif.c b/drivers/char/ipmi/ipmi_ssif.c index df8dd50b4cbe..1f7600c361e6 100644 --- a/drivers/char/ipmi/ipmi_ssif.c +++ b/drivers/char/ipmi/ipmi_ssif.c @@ -1945,7 +1945,7 @@ static int new_ssif_client(int addr, char *adapter_name, } } - strncpy(addr_info->binfo.type, DEVICE_NAME, + strscpy(addr_info->binfo.type, DEVICE_NAME, sizeof(addr_info->binfo.type)); addr_info->binfo.addr = addr; addr_info->binfo.platform_data = addr_info; -- cgit v1.2.3