From 19d1c64b7741d588af56dc70aa21e028737cd73f Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Mon, 23 Oct 2023 19:35:07 +0000 Subject: s390/ctcm: replace deprecated strncpy with strscpy strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. We expect chid to be NUL-terminated based on its use with format strings: CTCM_DBF_TEXT_(SETUP, CTC_DBF_INFO, "%s(%s) %s", CTCM_FUNTAIL, chid, ok ? "OK" : "failed"); Moreover, NUL-padding is not required as it is _only_ used in this one instance with a format string. Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. We can also drop the +1 from chid's declaration as we no longer need to be cautious about leaving a spot for a NUL-byte. Let's use the more idiomatic strscpy usage of (dest, src, sizeof(dest)) as this more closely ties the destination buffer to the length. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Signed-off-by: Justin Stitt Reviewed-by: Thorsten Winkler Tested-by: Thorsten Winkler Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20231023-strncpy-drivers-s390-net-ctcm_main-c-v1-1-265db6e78165@google.com Signed-off-by: Jakub Kicinski --- drivers/s390/net/ctcm_main.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'drivers/s390') diff --git a/drivers/s390/net/ctcm_main.c b/drivers/s390/net/ctcm_main.c index 6faf27136024..ac15d7c2b200 100644 --- a/drivers/s390/net/ctcm_main.c +++ b/drivers/s390/net/ctcm_main.c @@ -200,13 +200,13 @@ static void channel_free(struct channel *ch) static void channel_remove(struct channel *ch) { struct channel **c = &channels; - char chid[CTCM_ID_SIZE+1]; + char chid[CTCM_ID_SIZE]; int ok = 0; if (ch == NULL) return; else - strncpy(chid, ch->id, CTCM_ID_SIZE); + strscpy(chid, ch->id, sizeof(chid)); channel_free(ch); while (*c) { -- cgit v1.2.3 From e43e6d9582e0dcd20532310dbb9f47dfe7a74ace Mon Sep 17 00:00:00 2001 From: Justin Stitt Date: Mon, 23 Oct 2023 19:39:39 +0000 Subject: s390/qeth: replace deprecated strncpy with strscpy strncpy() is deprecated for use on NUL-terminated destination strings [1] and as such we should prefer more robust and less ambiguous string interfaces. We expect new_entry->dbf_name to be NUL-terminated based on its use with strcmp(): | if (strcmp(entry->dbf_name, name) == 0) { Moreover, NUL-padding is not required as new_entry is kzalloc'd just before this assignment: | new_entry = kzalloc(sizeof(struct qeth_dbf_entry), GFP_KERNEL); ... rendering any future NUL-byte assignments (like the ones strncpy() does) redundant. Considering the above, a suitable replacement is `strscpy` [2] due to the fact that it guarantees NUL-termination on the destination buffer without unnecessarily NUL-padding. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://manpages.debian.org/testing/linux-manual-4.8/strscpy.9.en.html [2] Link: https://github.com/KSPP/linux/issues/90 Signed-off-by: Justin Stitt Reviewed-by: Thorsten Winkler Tested-by: Thorsten Winkler Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20231023-strncpy-drivers-s390-net-qeth_core_main-c-v1-1-e7ce65454446@google.com Signed-off-by: Jakub Kicinski --- drivers/s390/net/qeth_core_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/s390') diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index cd783290bde5..6af2511e070c 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -6226,7 +6226,7 @@ static int qeth_add_dbf_entry(struct qeth_card *card, char *name) new_entry = kzalloc(sizeof(struct qeth_dbf_entry), GFP_KERNEL); if (!new_entry) goto err_dbg; - strncpy(new_entry->dbf_name, name, DBF_NAME_LEN); + strscpy(new_entry->dbf_name, name, sizeof(new_entry->dbf_name)); new_entry->dbf_info = card->debug; mutex_lock(&qeth_dbf_list_mutex); list_add(&new_entry->dbf_list, &qeth_dbf_list); -- cgit v1.2.3