From: Azeem Shaikh <azeemshaikh38@gmail.com>
To: "Martin K. Petersen" <martin.petersen@oracle.com>,
Kees Cook <keescook@chromium.org>
Cc: linux-hardening@vger.kernel.org,
Azeem Shaikh <azeemshaikh38@gmail.com>,
linux-scsi@vger.kernel.org, target-devel@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v3] scsi: target: Replace strlcpy with strscpy
Date: Thu, 31 Aug 2023 14:36:38 +0000 [thread overview]
Message-ID: <20230831143638.232596-1-azeemshaikh38@gmail.com> (raw)
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>
---
v3:
* Address readability comment.
v2:
* Replace all instances of strlcpy in this file instead of just 1.
* https://lore.kernel.org/all/20230830210724.4156575-1-azeemshaikh38@gmail.com/
v1:
* https://lore.kernel.org/all/20230830200717.4129442-1-azeemshaikh38@gmail.com/
drivers/target/target_core_configfs.c | 24 ++++++++++++------------
1 file changed, 12 insertions(+), 12 deletions(-)
diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index 936e5ff1b209..d5860c1c1f46 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -1392,16 +1392,16 @@ 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)) {
+ len = strscpy(buf, page, sizeof(buf));
+ if (len > 0) {
/* Strip any newline added from userspace. */
stripped = strstrip(buf);
len = strlen(stripped);
}
- if (len > INQUIRY_VENDOR_LEN) {
+ if (len < 0 || len > INQUIRY_VENDOR_LEN) {
pr_err("Emulated T10 Vendor Identification exceeds"
" INQUIRY_VENDOR_LEN: " __stringify(INQUIRY_VENDOR_LEN)
"\n");
@@ -1448,16 +1448,16 @@ 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)) {
+ len = strscpy(buf, page, sizeof(buf));
+ if (len > 0) {
/* Strip any newline added from userspace. */
stripped = strstrip(buf);
len = strlen(stripped);
}
- if (len > INQUIRY_MODEL_LEN) {
+ if (len < 0 || len > INQUIRY_MODEL_LEN) {
pr_err("Emulated T10 Vendor exceeds INQUIRY_MODEL_LEN: "
__stringify(INQUIRY_MODEL_LEN)
"\n");
@@ -1504,16 +1504,16 @@ 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)) {
+ len = strscpy(buf, page, sizeof(buf));
+ if (len > 0) {
/* Strip any newline added from userspace. */
stripped = strstrip(buf);
len = strlen(stripped);
}
- if (len > INQUIRY_REVISION_LEN) {
+ if (len < 0 || len > INQUIRY_REVISION_LEN) {
pr_err("Emulated T10 Revision exceeds INQUIRY_REVISION_LEN: "
__stringify(INQUIRY_REVISION_LEN)
"\n");
--
2.42.0.283.g2d96d420d3-goog
next reply other threads:[~2023-08-31 14:36 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-08-31 14:36 Azeem Shaikh [this message]
2023-08-31 18:42 ` [PATCH v3] scsi: target: Replace strlcpy with strscpy Kees Cook
2023-08-31 19:20 ` Azeem Shaikh
2023-08-31 21:02 ` Kees Cook
2023-09-05 9:56 ` Martin K. Petersen
2023-09-14 1:40 ` Martin K. Petersen
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