On Tue, 2024-10-22 at 13:43 +0000, Zicheng Qu wrote: > 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> > drivers/staging/iio/frequency/ad9832.c | 7 +++++-- > 1 file changed, 5 insertions(+), 2 deletions(-) > > diff --git a/drivers/staging/iio/frequency/ad9832.c > b/drivers/staging/iio/frequency/ad9832.c > index 6c390c4eb26d..492612e8f8ba 100644 > --- a/drivers/staging/iio/frequency/ad9832.c > +++ b/drivers/staging/iio/frequency/ad9832.c > @@ -129,12 +129,15 @@ static unsigned long ad9832_calc_freqreg(unsigned long > mclk, unsigned long fout) > 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) |
