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Commit 99594d19 authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Greg Kroah-Hartman
Browse files

wireless: wext-spy: Fix out-of-bounds warning 

[ Upstream commit e93bdd78406da9ed01554c51e38b2a02c8ef8025 ]

Fix the following out-of-bounds warning:

net/wireless/wext-spy.c:178:2: warning: 'memcpy' offset [25, 28] from the object at 'threshold' is out of the bounds of referenced subobject 'low' with type 'struct iw_quality' at offset 20 [-Warray-bounds]

The problem is that the original code is trying to copy data into a
couple of struct members adjacent to each other in a single call to
memcpy(). This causes a legitimate compiler warning because memcpy()
overruns the length of &threshold.low and &spydata->spy_thr_low. As
these are just a couple of struct members, fix this by using direct
assignments, instead of memcpy().

This helps with the ongoing efforts to globally enable -Warray-bounds
and get us closer to being able to tighten the FORTIFY_SOURCE routines
on memcpy().

Link: https://github.com/KSPP/linux/issues/109


Reported-by: default avatarkernel test robot <lkp@intel.com>
Signed-off-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210422200032.GA168995@embeddedor


Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 6a722d24

net/wireless/wext-spy.c

+7 −7
Original line number Diff line number Diff line
@@ -120,8 +120,8 @@ int iw_handler_set_thrspy(struct net_device * dev, 
		return -EOPNOTSUPP;



	/* Just do it */

	memcpy(&(spydata->spy_thr_low), &(threshold->low),

	       2 * sizeof(struct iw_quality));

	spydata->spy_thr_low = threshold->low;

	spydata->spy_thr_high = threshold->high;



	/* Clear flag */

	memset(spydata->spy_thr_under, '\0', sizeof(spydata->spy_thr_under));
@@ -147,8 +147,8 @@ int iw_handler_get_thrspy(struct net_device * dev, 
		return -EOPNOTSUPP;



	/* Just do it */

	memcpy(&(threshold->low), &(spydata->spy_thr_low),

	       2 * sizeof(struct iw_quality));

	threshold->low = spydata->spy_thr_low;

	threshold->high = spydata->spy_thr_high;



	return 0;

}
@@ -173,10 +173,10 @@ static void iw_send_thrspy_event(struct net_device * dev, 
	memcpy(threshold.addr.sa_data, address, ETH_ALEN);

	threshold.addr.sa_family = ARPHRD_ETHER;

	/* Copy stats */

	memcpy(&(threshold.qual), wstats, sizeof(struct iw_quality));

	threshold.qual = *wstats;

	/* Copy also thresholds */

	memcpy(&(threshold.low), &(spydata->spy_thr_low),

	       2 * sizeof(struct iw_quality));

	threshold.low = spydata->spy_thr_low;

	threshold.high = spydata->spy_thr_high;



	/* Send event to user space */

	wireless_send_event(dev, SIOCGIWTHRSPY, &wrqu, (char *) &threshold);