7936a19e94
strncpy() is deprecated for use on NUL-terminated destination strings
[1] and as such we should prefer more robust and less ambiguous string
interfaces.
This pattern of strncpy(dest, src, strlen(src)) is extremely bug-prone.
This pattern basically never results in NUL-terminated destination
strings unless `dest` was zero-initialized. The current implementation
may be accidentally correct as tw_dev is zero-allocated via:
host = scsi_host_alloc(&driver_template, sizeof(TW_Device_Extension));
...
tw_dev = shost_priv(host);
... wherein scsi_host_alloc() zero-allocates host:
shost = kzalloc(sizeof(struct Scsi_Host) + privsize, GFP_KERNEL);
Also, further suggesting this change is worthwhile is another strscpy()
usage in 3w-9xxx.c:
strscpy(tw_dev->tw_compat_info.driver_version, TW_DRIVER_VERSION,
sizeof(tw_dev->tw_compat_info.driver_version));
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.
Let's not be accidentally correct, let's be definitely correct.
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/20231023-strncpy-drivers-scsi-3w-sas-c-v1-1-4c40a1e99dfc@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.