From 838c7b8f1f278404d9d684c34a8cb26dc41aaaa1 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 24 Apr 2024 15:01:01 -0700 Subject: wifi: nl80211: Avoid address calculations via out of bounds array indexing 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 Fixes: e3eac9f32ec0 ("wifi: cfg80211: Annotate struct cfg80211_scan_request with __counted_by") Signed-off-by: Kees Cook Tested-by: Nathan Chancellor Link: https://msgid.link/20240424220057.work.819-kees@kernel.org Signed-off-by: Johannes Berg --- net/wireless/nl80211.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) (limited to 'net') diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 30ff9a470813..65c416e8d25e 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -9162,6 +9162,7 @@ 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; @@ -9207,21 +9208,20 @@ 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) { -- cgit v1.2.3