| Message ID | 20241022134354.574614-1-quzicheng@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | drivers/staging/iio/frequency/ad9832.c: fix division by zero in ad9832_calc_freqreg() | expand |
It would be better if the subject prefix were "staging: iio: ad9832:" [PATCH] staging: iio: ad9832: fix division by zero in ad9832_calc_freqreg() On Tue, Oct 22, 2024 at 01:43:54PM +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@vger.kernel.org> > Signed-off-by: Zicheng Qu <quzicheng@huawei.com> Otherwise it looks good. Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org> regards, dan carpenter
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@vger.kernel.org> > Signed-off-by: Zicheng Qu <quzicheng@huawei.com> > --- Reviewed-by: Nuno Sa <nuno.sa@analog.com> > 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) |
On Tue, 22 Oct 2024 17:25:21 +0300 Dan Carpenter <dan.carpenter@linaro.org> wrote: > It would be better if the subject prefix were "staging: iio: ad9832:" > > [PATCH] staging: iio: ad9832: fix division by zero in ad9832_calc_freqreg() Keep the frequency as well, though less important in staging as we have only a few drivers there. I fixed up the patch title and applied this to the fixes-togreg branch of iio.git. Thanks, Jonathan > > On Tue, Oct 22, 2024 at 01:43:54PM +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@vger.kernel.org> > > Signed-off-by: Zicheng Qu <quzicheng@huawei.com> > > Otherwise it looks good. > > Reviewed-by: Dan Carpenter <dan.carpenter@linaro.org> > > regards, > dan carpenter >
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) |
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@vger.kernel.org> Signed-off-by: Zicheng Qu <quzicheng@huawei.com> --- drivers/staging/iio/frequency/ad9832.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)