[PATCH AUTOSEL 4.19 074/146] rsi: fix memory alignment issue in ARM32 platforms

Sasha Levin
2018-10-31T23:48:01Z

From: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>

[ Upstream commit baa8caf4ab7af2d9e84b566b99fe919a4e9e7562 ]

During testing in ARM32 platforms, observed below kernel panic, as driver
accessing data beyond the allocated memory while submitting URB to USB.

Fix: Resolved this by specifying correct length by considering 64 bit
alignment. so that, USB bus driver will access only allocated memory.

Unit-test: Tested and confirm that driver bring up and scanning,
connection and data transfer works fine with this fix.

...skipping...
[ 25.389450] Unable to handle kernel paging request at virtual
address 5aa11422
[ 25.403078] Internal error: Oops: 5 [#1] SMP ARM
[ 25.407703] Modules linked in: rsi_usb
[ 25.411473] CPU: 1 PID: 317 Comm: RX-Thread Not tainted 4.18.0-rc7 #1
[ 25.419221] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[ 25.425764] PC is at skb_release_data+0x90/0x168
[ 25.430393] LR is at skb_release_all+0x28/0x2c
[ 25.434842] pc : [<807435b0>] lr : [<80742ba0>] psr: 200e0013 5aa1141e
[ 25.464633] Flags: nzCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none
[ 25.477524] Process RX-Thread (pid: 317, stack limit = 0x(ptrval))
[ 25.483709] Stack: (0xedf69ed8 to 0xedf6a000)
[ 25.569907] Backtrace:
[ 25.572368] [<80743520>] (skb_release_data) from [<80742ba0>]
(skb_release_all+0x28/0x2c)
[ 25.580555] r9:7f00258c r8:00000001 r7:ee355000 r6:eddab0d0
r5:eddab000 r4:eddbb840
[ 25.588308] [<80742b78>] (skb_release_all) from [<807432cc>]
(consume_skb+0x30/0x50)
[ 25.596055] r5:eddab000 r4:eddbb840
[ 25.599648] [<8074329c>] (consume_skb) from [<7f00117c>]
(rsi_usb_rx_thread+0x64/0x12c [rsi_usb])
[ 25.608524] r5:eddab000 r4:eddbb840
[ 25.612116] [<7f001118>] (rsi_usb_rx_thread [rsi_usb]) from
[<80142750>] (kthread+0x11c/0x15c)
[ 25.620735] r10:ee9ff9e0 r9:edcde3b8 r8:ee355000 r7:edf68000
r6:edd3a780 r5:00000000
[ 25.628567] r4:edcde380
[ 25.631110] [<80142634>] (kthread) from [<801010e8>]
(ret_from_fork+0x14/0x2c)
[ 25.638336] Exception stack(0xedf69fb0 to 0xedf69ff8)
[ 25.682929] ---[ end trace 8236a5496f5b5d3b ]---

Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/net/wireless/rsi/rsi_91x_usb.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_usb.c b/drivers/net/wireless/rsi/rsi_91x_usb.c
index c0a163e40402..f360690396dd 100644
--- a/drivers/net/wireless/rsi/rsi_91x_usb.c
+++ b/drivers/net/wireless/rsi/rsi_91x_usb.c
@@ -266,15 +266,17 @@ static void rsi_rx_done_handler(struct urb *urb)
if (urb->status)
goto out;

- if (urb->actual_length <= 0) {
- rsi_dbg(INFO_ZONE, "%s: Zero length packet\n", __func__);
+ if (urb->actual_length <= 0 ||
+ urb->actual_length > rx_cb->rx_skb->len) {
+ rsi_dbg(INFO_ZONE, "%s: Invalid packet length = %d\n",
+ __func__, urb->actual_length);
goto out;
}
if (skb_queue_len(&dev->rx_q) >= RSI_MAX_RX_PKTS) {
rsi_dbg(INFO_ZONE, "Max RX packets reached\n");
goto out;
}
- skb_put(rx_cb->rx_skb, urb->actual_length);
+ skb_trim(rx_cb->rx_skb, urb->actual_length);
skb_queue_tail(&dev->rx_q, rx_cb->rx_skb);

rsi_set_event(&dev->rx_thread.event);
@@ -308,6 +310,7 @@ static int rsi_rx_urb_submit(struct rsi_hw *adapter, u8 ep_num)
if (!skb)
return -ENOMEM;
skb_reserve(skb, MAX_DWORD_ALIGN_BYTES);
+ skb_put(skb, RSI_MAX_RX_USB_PKT_SIZE - MAX_DWORD_ALIGN_BYTES);
dword_align_bytes = (unsigned long)skb->data & 0x3f;
if (dword_align_bytes > 0)
skb_push(skb, dword_align_bytes);
@@ -319,7 +322,7 @@ static int rsi_rx_urb_submit(struct rsi_hw *adapter, u8 ep_num)
usb_rcvbulkpipe(dev->usbdev,
dev->bulkin_endpoint_addr[ep_num - 1]),
urb->transfer_buffer,
- RSI_MAX_RX_USB_PKT_SIZE,
+ skb->len,
rsi_rx_done_handler,
rx_cb);

--
2.17.1