From: Zicheng Qu <quzicheng@xxxxxxxxxx> commit 6bd301819f8f69331a55ae2336c8b111fc933f3d upstream. In the ad9832_write_frequency() function, clk_get_rate() might return 0. This can lead to a division by zero when calling ad9832_calc_freqreg(). The check if (fout > (clk_get_rate(st->mclk) / 2)) does not protect against the case when fout is 0. The ad9832_write_frequency() function is called from ad9832_write(), and fout is derived from a text buffer, which can contain any value. Link: https://lore.kernel.org/all/2024100904-CVE-2024-47663-9bdc@gregkh/ Fixes: ea707584bac1 ("Staging: IIO: DDS: AD9832 / AD9835 driver") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Zicheng Qu <quzicheng@xxxxxxxxxx> Reviewed-by: Nuno Sa <nuno.sa@xxxxxxxxxx> Reviewed-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Link: https://patch.msgid.link/20241022134354.574614-1-quzicheng@xxxxxxxxxx Signed-off-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/staging/iio/frequency/ad9832.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) --- a/drivers/staging/iio/frequency/ad9832.c +++ b/drivers/staging/iio/frequency/ad9832.c @@ -129,12 +129,15 @@ static unsigned long ad9832_calc_freqreg static int ad9832_write_frequency(struct ad9832_state *st, unsigned int addr, unsigned long fout) { + unsigned long clk_freq; unsigned long regval; - if (fout > (clk_get_rate(st->mclk) / 2)) + clk_freq = clk_get_rate(st->mclk); + + if (!clk_freq || fout > (clk_freq / 2)) return -EINVAL; - regval = ad9832_calc_freqreg(clk_get_rate(st->mclk), fout); + regval = ad9832_calc_freqreg(clk_freq, fout); st->freq_data[0] = cpu_to_be16((AD9832_CMD_FRE8BITSW << CMD_SHIFT) | (addr << ADD_SHIFT) | Patches currently in stable-queue which might be from quzicheng@xxxxxxxxxx are queue-5.4/staging-iio-frequency-ad9832-fix-division-by-zero-in-ad9832_calc_freqreg.patch
