Messages in this thread | | | Subject | Re: [PATCH 08/18] carl9170: prevent bounds-check bypass via speculative execution | From | Sergei Shtylyov <> | Date | Sat, 6 Jan 2018 13:01:15 +0300 |
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Hello!
On 1/6/2018 4:10 AM, Dan Williams wrote:
> Static analysis reports that 'queue' may be a user controlled value that > is used as a data dependency to read from the 'ar9170_qmap' array. In > order to avoid potential leaks of kernel memory values, block > speculative execution of the instruction stream that could issue reads > based on an invalid result of 'ar9170_qmap[queue]'. In this case the > value of 'ar9170_qmap[queue]' is immediately reused as an index to the > 'ar->edcf' array. > > Based on an original patch by Elena Reshetova. > > Cc: Christian Lamparter <chunkeey@googlemail.com> > Cc: Kalle Valo <kvalo@codeaurora.org> > Cc: linux-wireless@vger.kernel.org > Cc: netdev@vger.kernel.org > Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> > Signed-off-by: Dan Williams <dan.j.williams@intel.com> > --- > drivers/net/wireless/ath/carl9170/main.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/net/wireless/ath/carl9170/main.c b/drivers/net/wireless/ath/carl9170/main.c > index 988c8857d78c..0ff34cbe2b62 100644 > --- a/drivers/net/wireless/ath/carl9170/main.c > +++ b/drivers/net/wireless/ath/carl9170/main.c > @@ -41,6 +41,7 @@ > #include <linux/module.h> > #include <linux/etherdevice.h> > #include <linux/random.h> > +#include <linux/compiler.h> > #include <net/mac80211.h> > #include <net/cfg80211.h> > #include "hw.h" > @@ -1384,11 +1385,12 @@ static int carl9170_op_conf_tx(struct ieee80211_hw *hw, > const struct ieee80211_tx_queue_params *param) > { > struct ar9170 *ar = hw->priv; > + const u8 *elem; > int ret; > > mutex_lock(&ar->mutex); > - if (queue < ar->hw->queues) { > - memcpy(&ar->edcf[ar9170_qmap[queue]], param, sizeof(*param)); > + if ((elem = nospec_array_ptr(ar9170_qmap, queue, ar->hw->queues))) {
I bet this causes checkpatch.pl to complain. I don't see a dire need to upset it here, the assignment may well precede *if*...
> + memcpy(&ar->edcf[*elem], param, sizeof(*param)); > ret = carl9170_set_qos(ar); > } else { > ret = -EINVAL; >
MBR, Sergei
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