From 8b76bc6bcdb6b3d4847d4c6298b53759acc0849a Mon Sep 17 00:00:00 2001 From: Romain Perier Date: Mon, 22 Feb 2021 16:12:25 +0100 Subject: [PATCH] target: Manual replacement of the deprecated strlcpy() with return values The strlcpy() reads the entire source buffer first, it is dangerous if the source buffer lenght is unbounded or possibility non NULL-terminated. It can lead to linear read overflows, crashes, etc... As recommended in the deprecated interfaces [1], it should be replaced by strscpy. This commit replaces all calls to strlcpy that handle the return values by the corresponding strscpy calls with new handling of the return values (as it is quite different between the two functions). [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy Signed-off-by: Romain Perier --- drivers/target/target_core_configfs.c | 33 ++++++++------------------- 1 file changed, 9 insertions(+), 24 deletions(-) diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c index f0435228515505..676215cd8847ef 100644 --- a/drivers/target/target_core_configfs.c +++ b/drivers/target/target_core_configfs.c @@ -1325,16 +1325,11 @@ static ssize_t target_wwn_vendor_id_store(struct config_item *item, /* +2 to allow for a trailing (stripped) '\n' and null-terminator */ unsigned char buf[INQUIRY_VENDOR_LEN + 2]; char *stripped = NULL; - size_t len; + ssize_t len; ssize_t ret; - len = strlcpy(buf, page, sizeof(buf)); - if (len < sizeof(buf)) { - /* Strip any newline added from userspace. */ - stripped = strstrip(buf); - len = strlen(stripped); - } - if (len > INQUIRY_VENDOR_LEN) { + len = strscpy(buf, page, sizeof(buf)); + if (len == -E2BIG) { pr_err("Emulated T10 Vendor Identification exceeds" " INQUIRY_VENDOR_LEN: " __stringify(INQUIRY_VENDOR_LEN) "\n"); @@ -1381,16 +1376,11 @@ static ssize_t target_wwn_product_id_store(struct config_item *item, /* +2 to allow for a trailing (stripped) '\n' and null-terminator */ unsigned char buf[INQUIRY_MODEL_LEN + 2]; char *stripped = NULL; - size_t len; + ssize_t len; ssize_t ret; - len = strlcpy(buf, page, sizeof(buf)); - if (len < sizeof(buf)) { - /* Strip any newline added from userspace. */ - stripped = strstrip(buf); - len = strlen(stripped); - } - if (len > INQUIRY_MODEL_LEN) { + len = strscpy(buf, page, sizeof(buf)); + if (len == -E2BIG) { pr_err("Emulated T10 Vendor exceeds INQUIRY_MODEL_LEN: " __stringify(INQUIRY_MODEL_LEN) "\n"); @@ -1437,16 +1427,11 @@ static ssize_t target_wwn_revision_store(struct config_item *item, /* +2 to allow for a trailing (stripped) '\n' and null-terminator */ unsigned char buf[INQUIRY_REVISION_LEN + 2]; char *stripped = NULL; - size_t len; + ssize_t len; ssize_t ret; - len = strlcpy(buf, page, sizeof(buf)); - if (len < sizeof(buf)) { - /* Strip any newline added from userspace. */ - stripped = strstrip(buf); - len = strlen(stripped); - } - if (len > INQUIRY_REVISION_LEN) { + len = strscpy(buf, page, sizeof(buf)); + if (len == -E2BIG) { pr_err("Emulated T10 Revision exceeds INQUIRY_REVISION_LEN: " __stringify(INQUIRY_REVISION_LEN) "\n");