staging: iio: frequency: ad9834: Validate frequency parameter value

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: staging: iio: frequency: ad9834: Validate frequency parameter value In ad9834_write_frequency() clk_get_rate() can return 0. In such case ad9834_calc_freqreg() call will lead to division by zero. Checking 'if (fout > (clk_freq / 2))' doesn't protect in case of 'fout' is 0. ad9834_write_frequency() is called from ad9834_write(), where fout is taken from text buffer, which can contain any value. Modify parameters checking. Found by Linux Verification Center (linuxtesting.org) with SVACE.

References

• https://git.kernel.org/stable/c/5edc3a45ef428501000a7b23d0e1777a548907f6
• https://git.kernel.org/stable/c/0e727707a239d5c519fc9abc2f0fd913516a7e47
• https://git.kernel.org/stable/c/41cc91e3138fe52f8da92a81bebcd0e6cf488c53
• https://git.kernel.org/stable/c/d8b09a5edc4a634373158c1a405491de3c52e58a
• https://git.kernel.org/stable/c/3ba9abfcaa9e16bb91ed7e0e2b42e94a157a953e
• https://git.kernel.org/stable/c/dc12e49f970b08d8b007b8981b97e2eb93c0e89d
• https://git.kernel.org/stable/c/8961b245e8f92bccbaacfbbdf69eba60e3e7c227
• https://git.kernel.org/stable/c/b48aa991758999d4e8f9296c5bbe388f293ef465