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author | Hui Peng <benquike@gmail.com> | 2019-08-03 20:29:04 -0400 |
---|---|---|
committer | Kalle Valo <kvalo@codeaurora.org> | 2019-09-04 09:23:26 +0300 |
commit | 39d170b3cb62ba98567f5c4f40c27b5864b304e5 (patch) | |
tree | da5d9843daae65e788a711dc8a379f7736fd9709 /drivers/net | |
parent | 355cf31912014e6ff1bb1019ae4858cad12c68cf (diff) | |
download | linux-stable-39d170b3cb62ba98567f5c4f40c27b5864b304e5.tar.gz linux-stable-39d170b3cb62ba98567f5c4f40c27b5864b304e5.tar.bz2 linux-stable-39d170b3cb62ba98567f5c4f40c27b5864b304e5.zip |
ath6kl: fix a NULL-ptr-deref bug in ath6kl_usb_alloc_urb_from_pipe()
The `ar_usb` field of `ath6kl_usb_pipe_usb_pipe` objects
are initialized to point to the containing `ath6kl_usb` object
according to endpoint descriptors read from the device side, as shown
below in `ath6kl_usb_setup_pipe_resources`:
for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
endpoint = &iface_desc->endpoint[i].desc;
// get the address from endpoint descriptor
pipe_num = ath6kl_usb_get_logical_pipe_num(ar_usb,
endpoint->bEndpointAddress,
&urbcount);
......
// select the pipe object
pipe = &ar_usb->pipes[pipe_num];
// initialize the ar_usb field
pipe->ar_usb = ar_usb;
}
The driver assumes that the addresses reported in endpoint
descriptors from device side to be complete. If a device is
malicious and does not report complete addresses, it may trigger
NULL-ptr-deref `ath6kl_usb_alloc_urb_from_pipe` and
`ath6kl_usb_free_urb_to_pipe`.
This patch fixes the bug by preventing potential NULL-ptr-deref
(CVE-2019-15098).
Signed-off-by: Hui Peng <benquike@gmail.com>
Reported-by: Hui Peng <benquike@gmail.com>
Reported-by: Mathias Payer <mathias.payer@nebelwelt.net>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Diffstat (limited to 'drivers/net')
-rw-r--r-- | drivers/net/wireless/ath/ath6kl/usb.c | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c index 4defb7a0330f..53b66e9434c9 100644 --- a/drivers/net/wireless/ath/ath6kl/usb.c +++ b/drivers/net/wireless/ath/ath6kl/usb.c @@ -132,6 +132,10 @@ ath6kl_usb_alloc_urb_from_pipe(struct ath6kl_usb_pipe *pipe) struct ath6kl_urb_context *urb_context = NULL; unsigned long flags; + /* bail if this pipe is not initialized */ + if (!pipe->ar_usb) + return NULL; + spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags); if (!list_empty(&pipe->urb_list_head)) { urb_context = @@ -150,6 +154,10 @@ static void ath6kl_usb_free_urb_to_pipe(struct ath6kl_usb_pipe *pipe, { unsigned long flags; + /* bail if this pipe is not initialized */ + if (!pipe->ar_usb) + return; + spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags); pipe->urb_cnt++; |