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From: Takashi Iwai <tiwai@suse.de>
To: linux-wireless@vger.kernel.org
Cc: Amitkumar Karwar <amitkarwar@gmail.com>,
	Nishant Sarmukadam <nishants@marvell.com>,
	Ganapathi Bhat <gbhat@marvell.com>,
	Xinming Hu <huxinming820@gmail.com>,
	Kalle Valo <kvalo@codeaurora.org>,
	huangwen@venustech.com.cn, Solar Designer <solar@openwall.com>,
	Marcus Meissner <meissner@suse.de>
Subject: [PATCH 1/2] mwifiex: Fix possible buffer overflows at parsing bss descriptor
Date: Wed, 29 May 2019 14:52:19 +0200
Message-ID: <20190529125220.17066-2-tiwai@suse.de> (raw)
In-Reply-To: <20190529125220.17066-1-tiwai@suse.de>

mwifiex_update_bss_desc_with_ie() calls memcpy() unconditionally in
a couple places without checking the destination size.  Since the
source is given from user-space, this may trigger a heap buffer
overflow.

Fix it by putting the length check before performing memcpy().

This fix addresses CVE-2019-3846.

Reported-by: huangwen <huangwen@venustech.com.cn>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 drivers/net/wireless/marvell/mwifiex/scan.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/net/wireless/marvell/mwifiex/scan.c b/drivers/net/wireless/marvell/mwifiex/scan.c
index 935778ec9a1b..64ab6fe78c0d 100644
--- a/drivers/net/wireless/marvell/mwifiex/scan.c
+++ b/drivers/net/wireless/marvell/mwifiex/scan.c
@@ -1247,6 +1247,8 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter,
 		}
 		switch (element_id) {
 		case WLAN_EID_SSID:
+			if (element_len > IEEE80211_MAX_SSID_LEN)
+				return -EINVAL;
 			bss_entry->ssid.ssid_len = element_len;
 			memcpy(bss_entry->ssid.ssid, (current_ptr + 2),
 			       element_len);
@@ -1256,6 +1258,8 @@ int mwifiex_update_bss_desc_with_ie(struct mwifiex_adapter *adapter,
 			break;
 
 		case WLAN_EID_SUPP_RATES:
+			if (element_len > MWIFIEX_SUPPORTED_RATES)
+				return -EINVAL;
 			memcpy(bss_entry->data_rates, current_ptr + 2,
 			       element_len);
 			memcpy(bss_entry->supported_rates, current_ptr + 2,
-- 
2.16.4


  reply index

Thread overview: 9+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-29 12:52 [PATCH 0/2] Buffer overflow / read checks in mwifiex Takashi Iwai
2019-05-29 12:52 ` Takashi Iwai [this message]
2019-05-30 11:22   ` [PATCH 1/2] mwifiex: Fix possible buffer overflows at parsing bss descriptor Kalle Valo
2019-05-29 12:52 ` [PATCH 2/2] mwifiex: Abort at too short BSS descriptor element Takashi Iwai
2019-06-13 17:49   ` Brian Norris
2019-06-13 18:12     ` Takashi Iwai
2019-06-13 18:38       ` Brian Norris
2019-06-13 20:26         ` Brian Norris
2019-06-15  0:19     ` Brian Norris

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