a9baa16b4f
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 these fields to be NUL-terminated as the property names from
which they are derived are also NUL-terminated.
Moreover, NUL-padding is not required as our destination buffers are
already NUL-allocated and any future NUL-byte assignments are redundant
(like the ones that strncpy() does).
ibmvfc_probe() ->
| struct ibmvfc_host *vhost;
| struct Scsi_Host *shost;
...
| shost = scsi_host_alloc(&driver_template, sizeof(*vhost));
... **side note: is this a bug? Looks like a type to me ^^^^^**
...
| vhost = shost_priv(shost);
... where shost_priv() is:
| static inline void *shost_priv(struct Scsi_Host *shost)
| {
| return (void *)shost->hostdata;
| }
.. and:
scsi_host_alloc() ->
| shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
And for login_info->..., NUL-padding is also not required as it is
explicitly memset to 0:
| memset(login_info, 0, sizeof(*login_info));
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
Cc: <linux-hardening@vger.kernel.org>
Signed-off-by: Justin Stitt <justinstitt@google.com>
Link: https://lore.kernel.org/r/20231030-strncpy-drivers-scsi-ibmvscsi-ibmvfc-c-v1-1-5a4909688435@google.com
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.