wifi: nl80211: Avoid address calculations via out of bounds array indexing

[ Upstream commit 838c7b8f1f278404d9d684c34a8cb26dc41aaaa1 ]

Before request->channels[] can be used, request->n_channels must be set.
Additionally, address calculations for memory after the "channels" array
need to be calculated from the allocation base ("request") rather than
via the first "out of bounds" index of "channels", otherwise run-time
bounds checking will throw a warning.

Reported-by: Nathan Chancellor <nathan@kernel.org>
Fixes: e3eac9f32ec0 ("wifi: cfg80211: Annotate struct cfg80211_scan_request with __counted_by")
Signed-off-by: Kees Cook <keescook@chromium.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Link: https://msgid.link/20240424220057.work.819-kees@kernel.org
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Kees Cook 2024-04-24 15:01:01 -07:00 committed by Greg Kroah-Hartman
parent 166c9d2eef
commit ed74398642

View File

@ -9153,6 +9153,7 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
struct wiphy *wiphy;
int err, tmp, n_ssids = 0, n_channels, i;
size_t ie_len, size;
size_t ssids_offset, ie_offset;
wiphy = &rdev->wiphy;
@ -9198,21 +9199,20 @@ static int nl80211_trigger_scan(struct sk_buff *skb, struct genl_info *info)
return -EINVAL;
size = struct_size(request, channels, n_channels);
ssids_offset = size;
size = size_add(size, array_size(sizeof(*request->ssids), n_ssids));
ie_offset = size;
size = size_add(size, ie_len);
request = kzalloc(size, GFP_KERNEL);
if (!request)
return -ENOMEM;
request->n_channels = n_channels;
if (n_ssids)
request->ssids = (void *)&request->channels[n_channels];
request->ssids = (void *)request + ssids_offset;
request->n_ssids = n_ssids;
if (ie_len) {
if (n_ssids)
request->ie = (void *)(request->ssids + n_ssids);
else
request->ie = (void *)(request->channels + n_channels);
}
if (ie_len)
request->ie = (void *)request + ie_offset;
i = 0;
if (scan_freqs) {