[PATCH 4.9 47/78] staging: rtl8188eu: fix potential memory corruption in rtw_check_beacon_data()
From: gregkh@linuxfoundation.org
Date: 2021-03-15 13:57:46
Also in:
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
From: Dan Carpenter <redacted>
commit d4ac640322b06095128a5c45ba4a1e80929fe7f3 upstream.
The "ie_len" is a value in the 1-255 range that comes from the user. We
have to cap it to ensure that it's not too large or it could lead to
memory corruption.
Fixes: 9a7fe54ddc3a ("staging: r8188eu: Add source files for new driver - part 1")
Signed-off-by: Dan Carpenter <redacted>
Cc: stable <redacted>
Link: https://lore.kernel.org/r/YEHyQCrFZKTXyT7J@mwanda (local)
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/staging/rtl8188eu/core/rtw_ap.c | 5 +++++
1 file changed, 5 insertions(+)
--- a/drivers/staging/rtl8188eu/core/rtw_ap.c
+++ b/drivers/staging/rtl8188eu/core/rtw_ap.c@@ -917,6 +917,7 @@ int rtw_check_beacon_data(struct adapter /* SSID */ p = rtw_get_ie(ie + _BEACON_IE_OFFSET_, _SSID_IE_, &ie_len, (pbss_network->IELength - _BEACON_IE_OFFSET_)); if (p && ie_len > 0) { + ie_len = min_t(int, ie_len, sizeof(pbss_network->Ssid.Ssid)); memset(&pbss_network->Ssid, 0, sizeof(struct ndis_802_11_ssid)); memcpy(pbss_network->Ssid.Ssid, (p + 2), ie_len); pbss_network->Ssid.SsidLength = ie_len;
@@ -935,6 +936,7 @@ int rtw_check_beacon_data(struct adapter /* get supported rates */ p = rtw_get_ie(ie + _BEACON_IE_OFFSET_, _SUPPORTEDRATES_IE_, &ie_len, (pbss_network->IELength - _BEACON_IE_OFFSET_)); if (p) { + ie_len = min_t(int, ie_len, NDIS_802_11_LENGTH_RATES_EX); memcpy(supportRate, p + 2, ie_len); supportRateNum = ie_len; }
@@ -942,6 +944,8 @@ int rtw_check_beacon_data(struct adapter /* get ext_supported rates */ p = rtw_get_ie(ie + _BEACON_IE_OFFSET_, _EXT_SUPPORTEDRATES_IE_, &ie_len, pbss_network->IELength - _BEACON_IE_OFFSET_); if (p) { + ie_len = min_t(int, ie_len, + NDIS_802_11_LENGTH_RATES_EX - supportRateNum); memcpy(supportRate + supportRateNum, p + 2, ie_len); supportRateNum += ie_len; }
@@ -1057,6 +1061,7 @@ int rtw_check_beacon_data(struct adapter pht_cap->mcs.rx_mask[0] = 0xff; pht_cap->mcs.rx_mask[1] = 0x0; } + ie_len = min_t(int, ie_len, sizeof(pmlmepriv->htpriv.ht_cap)); memcpy(&pmlmepriv->htpriv.ht_cap, p+2, ie_len); }