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Justin Stitt ab7e8bb6e0 nvdimm/btt: replace deprecated strncpy with strscpy
Found with grep.

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 super->signature to be NUL-terminated based on its usage with
memcmp against a NUL-term'd buffer:
btt_devs.c:
253 | if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
btt.h:
13  | #define BTT_SIG "BTT_ARENA_INFO\0"

NUL-padding is not required as `super` is already zero-allocated:
btt.c:
985 | super = kzalloc(sizeof(struct btt_sb), GFP_NOIO);
... rendering any additional NUL-padding superfluous.

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 also use the more idiomatic strscpy usage of (dest, src,
sizeof(dest)) instead of (dest, src, XYZ_LEN) for buffers that the
compiler can determine the size of. This more tightly correlates the
destination buffer to the amount of bytes copied.

Side note, this pattern of memcmp() on two NUL-terminated strings should
really be changed to just a strncmp(), if i'm not mistaken? I see
multiple instances of this pattern in this system:

|       if (memcmp(super->signature, BTT_SIG, BTT_SIG_LEN) != 0)
|               return false;

where BIT_SIG is defined (weirdly) as a double NUL-terminated string:

|       #define BTT_SIG "BTT_ARENA_INFO\0"

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>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20231019-strncpy-drivers-nvdimm-btt-c-v2-1-366993878cf0@google.com
Signed-off-by: Kees Cook <keescook@chromium.org>
History 2023-12-01 09:51:43 -08:00
arch - Ignore invalid x2APIC entries in order to not waste per-CPU data 2023-11-19 13:46:17 -08:00
block blk-mq: make sure active queue usage is held for bio_integrity_prep() 2023-11-13 08:52:52 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto This push fixes a regression in ahash and hides the Kconfig sub-options for the jitter RNG. 2023-11-09 17:04:58 -08:00
Documentation - Ignore invalid x2APIC entries in order to not waste per-CPU data 2023-11-19 13:46:17 -08:00
drivers nvdimm/btt: replace deprecated strncpy with strscpy 2023-12-01 09:51:43 -08:00
fs afs: Add __counted_by for struct afs_acl and use struct_size() 2023-12-01 09:51:43 -08:00
include i40e: Annotate struct i40e_qvlist_info with __counted_by 2023-11-30 13:39:20 -08:00
init As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
io_uring io_uring/fdinfo: remove need for sqpoll lock for thread/pid retrieval 2023-11-15 06:35:46 -07:00
ipc Many singleton patches against the MM code. The patch series which are 2023-11-02 19:38:47 -10:00
kernel - Do the push of pending hrtimers away from a CPU which is being 2023-11-19 13:35:07 -08:00
lib Zstd fixes for v6.7 2023-11-14 23:35:31 -05:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm mm: more ptep_get() conversion 2023-11-15 15:30:09 -08:00
net SUNRPC: Replace strlcpy() with strscpy() 2023-11-30 12:18:36 -08:00
rust Kbuild updates for v6.7 2023-11-04 08:07:19 -10:00
samples samples: Replace strlcpy() with strscpy() 2023-11-30 12:20:53 -08:00
scripts Kbuild fixes for v6.7 2023-11-19 13:54:28 -08:00
security + Features 2023-11-03 09:48:17 -10:00
sound sound fixes for 6.7-rc2 2023-11-17 09:05:31 -05:00
tools turbostat-2023.11.07 2023-11-18 09:09:17 -08:00
usr arch: Remove Itanium (IA-64) architecture 2023-09-11 08:13:17 +00:00
virt ARM: 2023-09-07 13:52:20 -07:00
.clang-format iommu: Add for_each_group_device() 2023-05-23 08:15:51 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore kbuild: rpm-pkg: generate kernel.spec in rpmbuild/SPECS/ 2023-10-03 20:49:09 +09:00
.mailmap As usual, lots of singleton and doubleton patches all over the tree and 2023-11-02 20:53:31 -10:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS USB: Remove Wireless USB and UWB documentation 2023-08-09 14:17:32 +02:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS - Ignore invalid x2APIC entries in order to not waste per-CPU data 2023-11-19 13:46:17 -08:00
Makefile Linux 6.7-rc2 2023-11-19 15:02:14 -08:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

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.