* [PATCH] net: usb: aqc111: Fix out-of-bounds accesses in RX fixup
@ 2022-04-06 8:05 Marcin Kozlowski
2022-04-06 14:30 ` patchwork-bot+netdevbpf
0 siblings, 1 reply; 2+ messages in thread
From: Marcin Kozlowski @ 2022-04-06 8:05 UTC (permalink / raw)
To: netdev; +Cc: marcinguy
aqc111_rx_fixup() contains several out-of-bounds accesses that can be
triggered by a malicious (or defective) USB device, in particular:
- The metadata array (desc_offset..desc_offset+2*pkt_count) can be out of bounds,
causing OOB reads and (on big-endian systems) OOB endianness flips.
- A packet can overlap the metadata array, causing a later OOB
endianness flip to corrupt data used by a cloned SKB that has already
been handed off into the network stack.
- A packet SKB can be constructed whose tail is far beyond its end,
causing out-of-bounds heap data to be considered part of the SKB's
data.
Found doing variant analysis. Tested it with another driver (ax88179_178a), since
I don't have a aqc111 device to test it, but the code looks very similar.
Signed-off-by: Marcin Kozlowski <marcinguy@gmail.com>
---
drivers/net/usb/aqc111.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/net/usb/aqc111.c b/drivers/net/usb/aqc111.c
index ea06d10e1c21..ca409d450a29 100644
--- a/drivers/net/usb/aqc111.c
+++ b/drivers/net/usb/aqc111.c
@@ -1102,10 +1102,15 @@ static int aqc111_rx_fixup(struct usbnet *dev, struct sk_buff *skb)
if (start_of_descs != desc_offset)
goto err;
- /* self check desc_offset from header*/
- if (desc_offset >= skb_len)
+ /* self check desc_offset from header and make sure that the
+ * bounds of the metadata array are inside the SKB
+ */
+ if (pkt_count * 2 + desc_offset >= skb_len)
goto err;
+ /* Packets must not overlap the metadata array */
+ skb_trim(skb, desc_offset);
+
if (pkt_count == 0)
goto err;
--
2.17.1
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] net: usb: aqc111: Fix out-of-bounds accesses in RX fixup
2022-04-06 8:05 [PATCH] net: usb: aqc111: Fix out-of-bounds accesses in RX fixup Marcin Kozlowski
@ 2022-04-06 14:30 ` patchwork-bot+netdevbpf
0 siblings, 0 replies; 2+ messages in thread
From: patchwork-bot+netdevbpf @ 2022-04-06 14:30 UTC (permalink / raw)
To: Marcin Kozlowski; +Cc: netdev
Hello:
This patch was applied to netdev/net.git (master)
by David S. Miller <davem@davemloft.net>:
On Wed, 6 Apr 2022 10:05:37 +0200 you wrote:
> aqc111_rx_fixup() contains several out-of-bounds accesses that can be
> triggered by a malicious (or defective) USB device, in particular:
>
> - The metadata array (desc_offset..desc_offset+2*pkt_count) can be out of bounds,
> causing OOB reads and (on big-endian systems) OOB endianness flips.
> - A packet can overlap the metadata array, causing a later OOB
> endianness flip to corrupt data used by a cloned SKB that has already
> been handed off into the network stack.
> - A packet SKB can be constructed whose tail is far beyond its end,
> causing out-of-bounds heap data to be considered part of the SKB's
> data.
>
> [...]
Here is the summary with links:
- net: usb: aqc111: Fix out-of-bounds accesses in RX fixup
https://git.kernel.org/netdev/net/c/afb8e2465275
You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
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2022-04-06 8:05 [PATCH] net: usb: aqc111: Fix out-of-bounds accesses in RX fixup Marcin Kozlowski
2022-04-06 14:30 ` patchwork-bot+netdevbpf
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