This is a note to let you know that I've just added the patch titled
ath11k: Fix buffer overflow when scanning with extraie
to the 5.16-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
ath11k-fix-buffer-overflow-when-scanning-with-extraie.patch
and it can be found in the queue-5.16 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a658c929ded7ea3aee324c8c2a9635a5e5a38e7f Mon Sep 17 00:00:00 2001
From: Sven Eckelmann <sven@xxxxxxxxxxxxx>
Date: Wed, 8 Dec 2021 10:43:59 +0200
Subject: ath11k: Fix buffer overflow when scanning with extraie
From: Sven Eckelmann <sven@xxxxxxxxxxxxx>
commit a658c929ded7ea3aee324c8c2a9635a5e5a38e7f upstream.
If cfg80211 is providing extraie's for a scanning process then ath11k will
copy that over to the firmware. The extraie.len is a 32 bit value in struct
element_info and describes the amount of bytes for the vendor information
elements.
The WMI_TLV packet is having a special WMI_TAG_ARRAY_BYTE section. This
section can have a (payload) length up to 65535 bytes because the
WMI_TLV_LEN can store up to 16 bits. The code was missing such a check and
could have created a scan request which cannot be parsed correctly by the
firmware.
But the bigger problem was the allocation of the buffer. It has to align
the TLV sections by 4 bytes. But the code was using an u8 to store the
newly calculated length of this section (with alignment). And the new
calculated length was then used to allocate the skbuff. But the actual code
to copy in the data is using the extraie.len and not the calculated
"aligned" length.
The length of extraie with IEEE80211_HW_SINGLE_SCAN_ON_ALL_BANDS enabled
was 264 bytes during tests with a QCA Milan card. But it only allocated 8
bytes (264 bytes % 256) for it. As consequence, the code to memcpy the
extraie into the skb was then just overwriting data after skb->end. Things
like shinfo were therefore corrupted. This could usually be seen by a crash
in skb_zcopy_clear which tried to call a ubuf_info callback (using a bogus
address).
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-02892.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1
Cc: stable@xxxxxxxxxxxxxxx
Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx>
Signed-off-by: Kalle Valo <quic_kvalo@xxxxxxxxxxx>
Link: https://lore.kernel.org/r/20211207142913.1734635-1-sven@xxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/wireless/ath/ath11k/wmi.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/net/wireless/ath/ath11k/wmi.c
+++ b/drivers/net/wireless/ath/ath11k/wmi.c
@@ -2069,7 +2069,7 @@ int ath11k_wmi_send_scan_start_cmd(struc
void *ptr;
int i, ret, len;
u32 *tmp_ptr;
- u8 extraie_len_with_pad = 0;
+ u16 extraie_len_with_pad = 0;
struct hint_short_ssid *s_ssid = NULL;
struct hint_bssid *hint_bssid = NULL;
@@ -2088,7 +2088,7 @@ int ath11k_wmi_send_scan_start_cmd(struc
len += sizeof(*bssid) * params->num_bssid;
len += TLV_HDR_SIZE;
- if (params->extraie.len)
+ if (params->extraie.len && params->extraie.len <= 0xFFFF)
extraie_len_with_pad =
roundup(params->extraie.len, sizeof(u32));
len += extraie_len_with_pad;
@@ -2195,7 +2195,7 @@ int ath11k_wmi_send_scan_start_cmd(struc
FIELD_PREP(WMI_TLV_LEN, len);
ptr += TLV_HDR_SIZE;
- if (params->extraie.len)
+ if (extraie_len_with_pad)
memcpy(ptr, params->extraie.ptr,
params->extraie.len);
Patches currently in stable-queue which might be from sven@xxxxxxxxxxxxx are
queue-5.16/ath11k-fix-buffer-overflow-when-scanning-with-extraie.patch
