| Message ID | 20230830200717.4129442-1-azeemshaikh38@gmail.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | scsi: target: Replace strlcpy with strscpy | expand |
Please ignore this patch. There are more strlcpy()->strscpy() replacement in the same file that did not get included here. Will send out a v2 with all the changes to make it easier for reviewers. On Wed, Aug 30, 2023 at 4:07 PM Azeem Shaikh <azeemshaikh38@gmail.com> wrote: > > 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> > --- > drivers/target/target_core_configfs.c | 9 ++++----- > 1 file changed, 4 insertions(+), 5 deletions(-) > > diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c > index 936e5ff1b209..b3d2c14e2ea9 100644 > --- a/drivers/target/target_core_configfs.c > +++ b/drivers/target/target_core_configfs.c > @@ -1392,16 +1392,15 @@ 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 || strlen(stripped) > INQUIRY_VENDOR_LEN) { > pr_err("Emulated T10 Vendor Identification exceeds" > " INQUIRY_VENDOR_LEN: " __stringify(INQUIRY_VENDOR_LEN) > "\n"); > -- > 2.42.0.283.g2d96d420d3-goog > >
diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c index 936e5ff1b209..b3d2c14e2ea9 100644 --- a/drivers/target/target_core_configfs.c +++ b/drivers/target/target_core_configfs.c @@ -1392,16 +1392,15 @@ 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 || strlen(stripped) > INQUIRY_VENDOR_LEN) { pr_err("Emulated T10 Vendor Identification exceeds" " INQUIRY_VENDOR_LEN: " __stringify(INQUIRY_VENDOR_LEN) "\n");
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> --- drivers/target/target_core_configfs.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) -- 2.42.0.283.g2d96d420d3-goog