mirror_zfs/lib
Richard Yao 7584fbe846
Cleanup: Switch to strlcpy from strncpy
Coverity found a bug in `zfs_secpolicy_create_clone()` where it is
possible for us to pass an unterminated string when `zfs_get_parent()`
returns an error. Upon inspection, it is clear that using `strlcpy()`
would have avoided this issue.

Looking at the codebase, there are a number of other uses of `strncpy()`
that are unsafe and even when it is used safely, switching to
`strlcpy()` would make the code more readable. Therefore, we switch all
instances where we use `strncpy()` to use `strlcpy()`.

Unfortunately, we do not portably have access to `strlcpy()` in
tests/zfs-tests/cmd/zfs_diff-socket.c because it does not link to
libspl. Modifying the appropriate Makefile.am to try to link to it
resulted in an error from the naming choice used in the file. Trying to
disable the check on the file did not work on FreeBSD because Clang
ignores `#undef` when a definition is provided by `-Dstrncpy(...)=...`.
We workaround that by explictly including the C file from libspl into
the test. This makes things build correctly everywhere.

We add a deprecation warning to `config/Rules.am` and suppress it on the
remaining `strncpy()` usage. `strlcpy()` is not portably avaliable in
tests/zfs-tests/cmd/zfs_diff-socket.c, so we use `snprintf()` there as a
substitute.

This patch does not tackle the related problem of `strcpy()`, which is
even less safe. Thankfully, a quick inspection found that it is used far
more correctly than strncpy() was used. A quick inspection did not find
any problems with `strcpy()` usage outside of zhack, but it should be
said that I only checked around 90% of them.

Lastly, some of the fields in kstat_t varied in size by 1 depending on
whether they were in userspace or in the kernel. The origin of this
discrepancy appears to be 04a479f706 where
it was made for no apparent reason. It conflicts with the comment on
KSTAT_STRLEN, so we shrink the kernel field sizes to match the userspace
field sizes.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Ryan Moeller <ryan@iXsystems.com>
Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu>
Closes #13876
2022-09-27 16:35:29 -07:00
..
libavl cppcheck: explicitly exclude kernel code from userspace checks 2022-05-10 10:20:55 -07:00
libefi Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
libicp Introduce BLAKE3 checksums as an OpenZFS feature 2022-06-08 15:55:57 -07:00
libnvpair Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
libshare Fix unable to export zpool without nfs-utils 2022-09-16 13:43:26 -07:00
libspl Fix double declaration of getauxval() for FreeBSD PPC 2022-09-26 10:32:22 -07:00
libtpool Replace dead opensolaris.org license link 2022-07-11 14:16:13 -07:00
libunicode cppcheck: explicitly exclude kernel code from userspace checks 2022-05-10 10:20:55 -07:00
libuutil Cleanup: Remove unused uu_pname code 2022-09-19 17:33:52 -07:00
libzfs Cleanup: Switch to strlcpy from strncpy 2022-09-27 16:35:29 -07:00
libzfs_core Implement a new type of zfs receive: corrective receive (-c) 2022-07-28 15:52:46 -07:00
libzfsbootenv Fix unchecked return values and unused return values 2022-09-23 16:52:03 -07:00
libzpool Cleanup: Switch to strlcpy from strncpy 2022-09-27 16:35:29 -07:00
libzstd cppcheck: explicitly exclude kernel code from userspace checks 2022-05-10 10:20:55 -07:00
libzutil Fix userland resource leaks 2022-09-23 16:55:26 -07:00
Makefile.am autoconf: use include directives instead of recursing down lib 2022-05-10 10:18:11 -07:00