brcmf_notify_auth_frame_rx() takes the frame length from the firmware event and copies the frame body with the management header offset subtracted: u32 mgmt_frame_len = e->datalen - sizeof(struct brcmf_rx_mgmt_data); ... memcpy(&mgmt_frame->u, frame, mgmt_frame_len - offsetof(struct ieee80211_mgmt, u)); The only length check is e->datalen >= sizeof(*rxframe), so mgmt_frame_len can be anything from 0 up. offsetof(struct ieee80211_mgmt, u) is 24. When mgmt_frame_len is below that, the subtraction wraps as an unsigned value to a huge length. The memcpy then runs far past the kzalloc'd buffer. A malicious or malfunctioning AP can make the frame short during the external SAE auth exchange, so this is a remotely triggered heap overflow. Reject frames shorter than the management header offset before the copy. Fixes: 66f909308a7c ("wifi: brcmfmac: cyw: support external SAE authentication in station mode") Link: https://lore.kernel.org/r/178214417708.2368577.16740907093694208834@maoyixie.com Cc: stable@vger.kernel.org Co-developed-by: Kaixuan Li Signed-off-by: Kaixuan Li Signed-off-by: Maoyi Xie --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c index ce09d44fa73cf..873754be5174b 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cyw/core.c @@ -293,6 +293,12 @@ brcmf_notify_auth_frame_rx(struct brcmf_if *ifp, return -EINVAL; } + if (mgmt_frame_len < offsetof(struct ieee80211_mgmt, u)) { + bphy_err(drvr, "Event %s (%d) frame too small. Ignore\n", + brcmf_fweh_event_name(e->event_code), e->event_code); + return -EINVAL; + } + wdev = &ifp->vif->wdev; WARN_ON(!wdev);