Richard Yao a51288aabb Fix unsafe string operations ... Coverity caught unsafe use of `strcpy()` in `ztest_dmu_objset_own()`, `nfs_init_tmpfile()` and `dump_snapshot()`. It also caught an unsafe use of `strlcat()` in `nfs_init_tmpfile()`. Inspired by this, I did an audit of every single usage of `strcpy()` and `strcat()` in the code. If I could not prove that the usage was safe, I changed the code to use either `strlcpy()` or `strlcat()`, depending on which function was originally used. In some cases, `snprintf()` was used to replace multiple uses of `strcat` because it was cleaner. Whenever I changed a function, I preferred to use `sizeof(dst)` when the compiler is able to provide the string size via that. When it could not because the string was passed by a caller, I checked the entire call tree of the function to find out how big the buffer was and hard coded it. Hardcoding is less than ideal, but it is safe unless someone shrinks the buffer sizes being passed. Additionally, Coverity reported three more string related issues: * It caught a case where we do an overlapping memory copy in a call to `snprintf()`. We fix that via `kmem_strdup()` and `kmem_strfree()`. * It caught `sizeof (buf)` being used instead of `buflen` in `zdb_nicenum()`'s call to `zfs_nicenum()`, which is passed to `snprintf()`. We change that to pass `buflen`. * It caught a theoretical unterminated string passed to `strcmp()`. This one is likely a false positive, but we have the information needed to do this more safely, so we change this to silence the false positive not just in coverity, but potentially other static analysis tools too. We switch to `strncmp()`. * There was a false positive in tests/zfs-tests/cmd/dir_rd_update.c. We suppress it by switching to `snprintf()` since other static analysis tools might complain about it too. Interestingly, there is a possible real bug there too, since it assumes that the passed directory path ends with '/'. We add a '/' to fix that potential bug. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Richard Yao <richard.yao@alumni.stonybrook.edu> Closes #13913		2022-09-27 16:47:24 -07:00
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freebsd	Replace dead opensolaris.org license link	2022-07-11 14:16:13 -07:00
linux	Fix unsafe string operations	2022-09-27 16:47:24 -07:00