linux.git/drivers/usb/gadget/function/f_ncm.c, branch v6.8 Linux kernel source tree usb: gadget: ncm: Fix handling of zero block length packets 2024-03-05T13:20:40+00:00 Krishna Kurapati quic_kriskura@quicinc.com 2024-02-28T11:54:41+00:00 f90ce1e04cbcc76639d6cba0fdbd820cd80b3c70 While connecting to a Linux host with CDC_NCM_NTB_DEF_SIZE_TX set to 65536, it has been observed that we receive short packets, which come at interval of 5-10 seconds sometimes and have block length zero but still contain 1-2 valid datagrams present. According to the NCM spec: "If wBlockLength = 0x0000, the block is terminated by a short packet. In this case, the USB transfer must still be shorter than dwNtbInMaxSize or dwNtbOutMaxSize. If exactly dwNtbInMaxSize or dwNtbOutMaxSize bytes are sent, and the size is a multiple of wMaxPacketSize for the given pipe, then no ZLP shall be sent. wBlockLength= 0x0000 must be used with extreme care, because of the possibility that the host and device may get out of sync, and because of test issues. wBlockLength = 0x0000 allows the sender to reduce latency by starting to send a very large NTB, and then shortening it when the sender discovers that there’s not sufficient data to justify sending a large NTB" However, there is a potential issue with the current implementation, as it checks for the occurrence of multiple NTBs in a single giveback by verifying if the leftover bytes to be processed is zero or not. If the block length reads zero, we would process the same NTB infintely because the leftover bytes is never zero and it leads to a crash. Fix this by bailing out if block length reads zero. Cc: stable@vger.kernel.org Fixes: 427694cfaafa ("usb: gadget: ncm: Handle decoding of multiple NTB's in unwrap call") Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Link: https://lore.kernel.org/r/20240228115441.2105585-1-quic_kriskura@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
While connecting to a Linux host with CDC_NCM_NTB_DEF_SIZE_TX
set to 65536, it has been observed that we receive short packets,
which come at interval of 5-10 seconds sometimes and have block
length zero but still contain 1-2 valid datagrams present.

According to the NCM spec:

"If wBlockLength = 0x0000, the block is terminated by a
short packet. In this case, the USB transfer must still
be shorter than dwNtbInMaxSize or dwNtbOutMaxSize. If
exactly dwNtbInMaxSize or dwNtbOutMaxSize bytes are sent,
and the size is a multiple of wMaxPacketSize for the
given pipe, then no ZLP shall be sent.

wBlockLength= 0x0000 must be used with extreme care, because
of the possibility that the host and device may get out of
sync, and because of test issues.

wBlockLength = 0x0000 allows the sender to reduce latency by
starting to send a very large NTB, and then shortening it when
the sender discovers that there’s not sufficient data to justify
sending a large NTB"

However, there is a potential issue with the current implementation,
as it checks for the occurrence of multiple NTBs in a single
giveback by verifying if the leftover bytes to be processed is zero
or not. If the block length reads zero, we would process the same
NTB infintely because the leftover bytes is never zero and it leads
to a crash. Fix this by bailing out if block length reads zero.

Cc: stable@vger.kernel.org
Fixes: 427694cfaafa ("usb: gadget: ncm: Handle decoding of multiple NTB's in unwrap call")
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20240228115441.2105585-1-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs 2024-02-19T08:33:27+00:00 Krishna Kurapati quic_kriskura@quicinc.com 2024-02-05T07:46:50+00:00 76c51146820c5dac629f21deafab0a7039bc3ccd It is observed sometimes when tethering is used over NCM with Windows 11 as host, at some instances, the gadget_giveback has one byte appended at the end of a proper NTB. When the NTB is parsed, unwrap call looks for any leftover bytes in SKB provided by u_ether and if there are any pending bytes, it treats them as a separate NTB and parses it. But in case the second NTB (as per unwrap call) is faulty/corrupt, all the datagrams that were parsed properly in the first NTB and saved in rx_list are dropped. Adding a few custom traces showed the following: [002] d..1 7828.532866: dwc3_gadget_giveback: ep1out: req 000000003868811a length 1025/16384 zsI ==> 0 [002] d..1 7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb toprocess: 1025 [002] d..1 7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342 [002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb seq: 0xce67 [002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x400 [002] d..1 7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb ndp_len: 0x10 [002] d..1 7828.532869: ncm_unwrap_ntb: K: Parsed NTB with 1 frames In this case, the giveback is of 1025 bytes and block length is 1024. The rest 1 byte (which is 0x00) won't be parsed resulting in drop of all datagrams in rx_list. Same is case with packets of size 2048: [002] d..1 7828.557948: dwc3_gadget_giveback: ep1out: req 0000000011dfd96e length 2049/16384 zsI ==> 0 [002] d..1 7828.557949: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342 [002] d..1 7828.557950: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x800 Lecroy shows one byte coming in extra confirming that the byte is coming in from PC: Transfer 2959 - Bytes Transferred(1025) Timestamp((18.524 843 590) - Transaction 8391 - Data(1025 bytes) Timestamp(18.524 843 590) --- Packet 4063861 Data(1024 bytes) Duration(2.117us) Idle(14.700ns) Timestamp(18.524 843 590) --- Packet 4063863 Data(1 byte) Duration(66.160ns) Time(282.000ns) Timestamp(18.524 845 722) According to Windows driver, no ZLP is needed if wBlockLength is non-zero, because the non-zero wBlockLength has already told the function side the size of transfer to be expected. However, there are in-market NCM devices that rely on ZLP as long as the wBlockLength is multiple of wMaxPacketSize. To deal with such devices, it pads an extra 0 at end so the transfer is no longer multiple of wMaxPacketSize. Cc: <stable@vger.kernel.org> Fixes: 9f6ce4240a2b ("usb: gadget: f_ncm.c added") Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Link: https://lore.kernel.org/r/20240205074650.200304-1-quic_kriskura@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
It is observed sometimes when tethering is used over NCM with Windows 11
as host, at some instances, the gadget_giveback has one byte appended at
the end of a proper NTB. When the NTB is parsed, unwrap call looks for
any leftover bytes in SKB provided by u_ether and if there are any pending
bytes, it treats them as a separate NTB and parses it. But in case the
second NTB (as per unwrap call) is faulty/corrupt, all the datagrams that
were parsed properly in the first NTB and saved in rx_list are dropped.

Adding a few custom traces showed the following:
[002] d..1  7828.532866: dwc3_gadget_giveback: ep1out:
req 000000003868811a length 1025/16384 zsI ==> 0
[002] d..1  7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb toprocess: 1025
[002] d..1  7828.532867: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342
[002] d..1  7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb seq: 0xce67
[002] d..1  7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x400
[002] d..1  7828.532868: ncm_unwrap_ntb: K: ncm_unwrap_ntb ndp_len: 0x10
[002] d..1  7828.532869: ncm_unwrap_ntb: K: Parsed NTB with 1 frames

In this case, the giveback is of 1025 bytes and block length is 1024.
The rest 1 byte (which is 0x00) won't be parsed resulting in drop of
all datagrams in rx_list.

Same is case with packets of size 2048:
[002] d..1  7828.557948: dwc3_gadget_giveback: ep1out:
req 0000000011dfd96e length 2049/16384 zsI ==> 0
[002] d..1  7828.557949: ncm_unwrap_ntb: K: ncm_unwrap_ntb nth: 1751999342
[002] d..1  7828.557950: ncm_unwrap_ntb: K: ncm_unwrap_ntb blk_len: 0x800

Lecroy shows one byte coming in extra confirming that the byte is coming
in from PC:

 Transfer 2959 - Bytes Transferred(1025)  Timestamp((18.524 843 590)
 - Transaction 8391 - Data(1025 bytes) Timestamp(18.524 843 590)
 --- Packet 4063861
       Data(1024 bytes)
       Duration(2.117us) Idle(14.700ns) Timestamp(18.524 843 590)
 --- Packet 4063863
       Data(1 byte)
       Duration(66.160ns) Time(282.000ns) Timestamp(18.524 845 722)

According to Windows driver, no ZLP is needed if wBlockLength is non-zero,
because the non-zero wBlockLength has already told the function side the
size of transfer to be expected. However, there are in-market NCM devices
that rely on ZLP as long as the wBlockLength is multiple of wMaxPacketSize.
To deal with such devices, it pads an extra 0 at end so the transfer is no
longer multiple of wMaxPacketSize.

Cc: <stable@vger.kernel.org>
Fixes: 9f6ce4240a2b ("usb: gadget: f_ncm.c added")
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20240205074650.200304-1-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: ncm: Fix endianness of wMaxSegmentSize variable in ecm_desc 2024-01-28T00:28:28+00:00 Krishna Kurapati quic_kriskura@quicinc.com 2024-01-18T15:48:53+00:00 9dc292413c56a2d01e34787d3fc4a76635e4a498 Recent commit [1] added support for changing max segment size of the NCM interface via configfs. But the value of segment size value stored in ncm_opts need to be converted to little endian before saving it in ecm_desc. Also while initialising the value of segment size in opts during instance allocation, the value ETH_FRAME_LEN needs to be assigned directly without any conversion as ETH_FRAME_LEN and the variable max_segment_size are native endian. The current implementaion modifies it into little endian thus breaking things for big endian targets. Fix endianness while assigning these variables. While at it, fix up some stray spaces in comments added in code. [1]: https://lore.kernel.org/all/20231221153216.18657-1-quic_kriskura@quicinc.com/ Fixes: 1900daeefd3e ("usb: gadget: ncm: Add support to update wMaxSegmentSize via configfs") Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Link: https://lore.kernel.org/r/20240118154910.8765-1-quic_kriskura@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Recent commit [1] added support for changing max segment size of the NCM
interface via configfs. But the value of segment size value stored in
ncm_opts need to be converted to little endian before saving it in
ecm_desc. Also while initialising the value of segment size in opts during
instance allocation, the value ETH_FRAME_LEN needs to be assigned directly
without any conversion as ETH_FRAME_LEN and the variable max_segment_size
are native endian. The current implementaion modifies it into little endian
thus breaking things for big endian targets.

Fix endianness while assigning these variables.
While at it, fix up some stray spaces in comments added in code.

[1]: https://lore.kernel.org/all/20231221153216.18657-1-quic_kriskura@quicinc.com/

Fixes: 1900daeefd3e ("usb: gadget: ncm: Add support to update wMaxSegmentSize via configfs")
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20240118154910.8765-1-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: ncm: Add support to update wMaxSegmentSize via configfs 2024-01-04T15:01:14+00:00 Krishna Kurapati quic_kriskura@quicinc.com 2023-12-21T15:32:16+00:00 1900daeefd3ebde61199649143085a2dfdebf55c The max segment size is currently limited to the ethernet frame length of the kernel which happens to be 1514 at this point in time. However the NCM specification limits it to 64K for sixtenn bit NTB's. For peer to peer connections, increasing the segment size gives better throughput. Add support to configure this value before configfs symlink is created. Also since the NTB Out/In buffer sizes are fixed at 16384 bytes, limit the segment size to an upper cap of 8000 to allow at least a minimum of 2 MTU sized datagrams to be aggregated. Set the default MTU size for the ncm interface during function bind before network interface is registered allowing MTU to be set in parity with wMaxSegmentSize. Update gadget documentation describing the new configfs property. Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com> Link: https://lore.kernel.org/r/20231221153216.18657-1-quic_kriskura@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
The max segment size is currently limited to the ethernet frame length of
the kernel which happens to be 1514 at this point in time. However the NCM
specification limits it to 64K for sixtenn bit NTB's. For peer to peer
connections, increasing the segment size gives better throughput.

Add support to configure this value before configfs symlink is created.
Also since the NTB Out/In buffer sizes are fixed at 16384 bytes, limit the
segment size to an upper cap of 8000 to allow at least a minimum of 2 MTU
sized datagrams to be aggregated.

Set the default MTU size for the ncm interface during function bind before
network interface is registered allowing MTU to be set in parity with
wMaxSegmentSize.

Update gadget documentation describing the new configfs property.

Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Link: https://lore.kernel.org/r/20231221153216.18657-1-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: f_ncm: Always set current gadget in ncm_bind() 2023-10-21T10:54:53+00:00 Hardik Gajjar hgajjar@de.adit-jv.com 2023-10-20T15:33:24+00:00 a04224da1f3424b2c607b12a3bd1f0e302fb8231 Previously, gadget assignment to the net device occurred exclusively during the initial binding attempt. Nevertheless, the gadget pointer could change during bind/unbind cycles due to various conditions, including the unloading/loading of the UDC device driver or the detachment/reconnection of an OTG-capable USB hub device. This patch relocates the gether_set_gadget() function out from ncm_opts->bound condition check, ensuring that the correct gadget is assigned during each bind request. The provided logs demonstrate the consistency of ncm_opts throughout the power cycle, while the gadget may change. * OTG hub connected during boot up and assignment of gadget and ncm_opts pointer [ 2.366301] usb 2-1.5: New USB device found, idVendor=2996, idProduct=0105 [ 2.366304] usb 2-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 2.366306] usb 2-1.5: Product: H2H Bridge [ 2.366308] usb 2-1.5: Manufacturer: Aptiv [ 2.366309] usb 2-1.5: SerialNumber: 13FEB2021 [ 2.427989] usb 2-1.5: New USB device found, VID=2996, PID=0105 [ 2.428959] dabridge 2-1.5:1.0: dabridge 2-4 total endpoints=5, 0000000093a8d681 [ 2.429710] dabridge 2-1.5:1.0: P(0105) D(22.06.22) F(17.3.16) H(1.1) high-speed [ 2.429714] dabridge 2-1.5:1.0: Hub 2-2 P(0151) V(06.87) [ 2.429956] dabridge 2-1.5:1.0: All downstream ports in host mode [ 2.430093] gadget 000000003c414d59 ------> gadget pointer * NCM opts and associated gadget pointer during First ncm_bind [ 34.763929] NCM opts 00000000aa304ac9 [ 34.763930] NCM gadget 000000003c414d59 * OTG capable hub disconnecte or assume driver unload. [ 97.203114] usb 2-1: USB disconnect, device number 2 [ 97.203118] usb 2-1.1: USB disconnect, device number 3 [ 97.209217] usb 2-1.5: USB disconnect, device number 4 [ 97.230990] dabr_udc deleted * Reconnect the OTG hub or load driver assaign new gadget pointer. [ 111.534035] usb 2-1.1: New USB device found, idVendor=2996, idProduct=0120, bcdDevice= 6.87 [ 111.534038] usb 2-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 111.534040] usb 2-1.1: Product: Vendor [ 111.534041] usb 2-1.1: Manufacturer: Aptiv [ 111.534042] usb 2-1.1: SerialNumber: Superior [ 111.535175] usb 2-1.1: New USB device found, VID=2996, PID=0120 [ 111.610995] usb 2-1.5: new high-speed USB device number 8 using xhci-hcd [ 111.630052] usb 2-1.5: New USB device found, idVendor=2996, idProduct=0105, bcdDevice=21.02 [ 111.630055] usb 2-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [ 111.630057] usb 2-1.5: Product: H2H Bridge [ 111.630058] usb 2-1.5: Manufacturer: Aptiv [ 111.630059] usb 2-1.5: SerialNumber: 13FEB2021 [ 111.687464] usb 2-1.5: New USB device found, VID=2996, PID=0105 [ 111.690375] dabridge 2-1.5:1.0: dabridge 2-8 total endpoints=5, 000000000d87c961 [ 111.691172] dabridge 2-1.5:1.0: P(0105) D(22.06.22) F(17.3.16) H(1.1) high-speed [ 111.691176] dabridge 2-1.5:1.0: Hub 2-6 P(0151) V(06.87) [ 111.691646] dabridge 2-1.5:1.0: All downstream ports in host mode [ 111.692298] gadget 00000000dc72f7a9 --------> new gadget ptr on connect * NCM opts and associated gadget pointer during second ncm_bind [ 113.271786] NCM opts 00000000aa304ac9 -----> same opts ptr used during first bind [ 113.271788] NCM gadget 00000000dc72f7a9 ----> however new gaget ptr, that will not set in net_device due to ncm_opts->bound = true Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com> Link: https://lore.kernel.org/r/20231020153324.82794-1-hgajjar@de.adit-jv.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Previously, gadget assignment to the net device occurred exclusively
during the initial binding attempt.

Nevertheless, the gadget pointer could change during bind/unbind
cycles due to various conditions, including the unloading/loading
of the UDC device driver or the detachment/reconnection of an
OTG-capable USB hub device.

This patch relocates the gether_set_gadget() function out from
ncm_opts->bound condition check, ensuring that the correct gadget
is assigned during each bind request.

The provided logs demonstrate the consistency of ncm_opts throughout
the power cycle, while the gadget may change.

* OTG hub connected during boot up and assignment of gadget and
  ncm_opts pointer

[    2.366301] usb 2-1.5: New USB device found, idVendor=2996, idProduct=0105
[    2.366304] usb 2-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[    2.366306] usb 2-1.5: Product: H2H Bridge
[    2.366308] usb 2-1.5: Manufacturer: Aptiv
[    2.366309] usb 2-1.5: SerialNumber: 13FEB2021
[    2.427989] usb 2-1.5: New USB device found, VID=2996, PID=0105
[    2.428959] dabridge 2-1.5:1.0: dabridge 2-4 total endpoints=5, 0000000093a8d681
[    2.429710] dabridge 2-1.5:1.0: P(0105) D(22.06.22) F(17.3.16) H(1.1) high-speed
[    2.429714] dabridge 2-1.5:1.0: Hub 2-2 P(0151) V(06.87)
[    2.429956] dabridge 2-1.5:1.0: All downstream ports in host mode

[    2.430093] gadget 000000003c414d59 ------> gadget pointer

* NCM opts and associated gadget pointer during First ncm_bind

[   34.763929] NCM opts 00000000aa304ac9
[   34.763930] NCM gadget 000000003c414d59

* OTG capable hub disconnecte or assume driver unload.

[   97.203114] usb 2-1: USB disconnect, device number 2
[   97.203118] usb 2-1.1: USB disconnect, device number 3
[   97.209217] usb 2-1.5: USB disconnect, device number 4
[   97.230990] dabr_udc deleted

* Reconnect the OTG hub or load driver assaign new gadget pointer.

[  111.534035] usb 2-1.1: New USB device found, idVendor=2996, idProduct=0120, bcdDevice= 6.87
[  111.534038] usb 2-1.1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  111.534040] usb 2-1.1: Product: Vendor
[  111.534041] usb 2-1.1: Manufacturer: Aptiv
[  111.534042] usb 2-1.1: SerialNumber: Superior
[  111.535175] usb 2-1.1: New USB device found, VID=2996, PID=0120
[  111.610995] usb 2-1.5: new high-speed USB device number 8 using xhci-hcd
[  111.630052] usb 2-1.5: New USB device found, idVendor=2996, idProduct=0105, bcdDevice=21.02
[  111.630055] usb 2-1.5: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[  111.630057] usb 2-1.5: Product: H2H Bridge
[  111.630058] usb 2-1.5: Manufacturer: Aptiv
[  111.630059] usb 2-1.5: SerialNumber: 13FEB2021
[  111.687464] usb 2-1.5: New USB device found, VID=2996, PID=0105
[  111.690375] dabridge 2-1.5:1.0: dabridge 2-8 total endpoints=5, 000000000d87c961
[  111.691172] dabridge 2-1.5:1.0: P(0105) D(22.06.22) F(17.3.16) H(1.1) high-speed
[  111.691176] dabridge 2-1.5:1.0: Hub 2-6 P(0151) V(06.87)
[  111.691646] dabridge 2-1.5:1.0: All downstream ports in host mode

[  111.692298] gadget 00000000dc72f7a9 --------> new gadget ptr on connect

* NCM opts and associated gadget pointer during second ncm_bind

[  113.271786] NCM opts 00000000aa304ac9 -----> same opts ptr used during first bind
[  113.271788] NCM gadget 00000000dc72f7a9 ----> however new gaget ptr, that will not set
                                                 in net_device due to ncm_opts->bound = true

Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com>
Link: https://lore.kernel.org/r/20231020153324.82794-1-hgajjar@de.adit-jv.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: ncm: Handle decoding of multiple NTB's in unwrap call 2023-10-02T11:38:10+00:00 Krishna Kurapati quic_kriskura@quicinc.com 2023-09-27T10:58:58+00:00 427694cfaafa565a3db5c5ea71df6bc095dca92f When NCM is used with hosts like Windows PC, it is observed that there are multiple NTB's contained in one usb request giveback. Since the driver unwraps the obtained request data assuming only one NTB is present, we loose the subsequent NTB's present resulting in data loss. Fix this by checking the parsed block length with the obtained data length in usb request and continue parsing after the last byte of current NTB. Cc: stable@vger.kernel.org Fixes: 9f6ce4240a2b ("usb: gadget: f_ncm.c added") Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Link: https://lore.kernel.org/r/20230927105858.12950-1-quic_kriskura@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
When NCM is used with hosts like Windows PC, it is observed that there are
multiple NTB's contained in one usb request giveback. Since the driver
unwraps the obtained request data assuming only one NTB is present, we
loose the subsequent NTB's present resulting in data loss.

Fix this by checking the parsed block length with the obtained data
length in usb request and continue parsing after the last byte of current
NTB.

Cc: stable@vger.kernel.org
Fixes: 9f6ce4240a2b ("usb: gadget: f_ncm.c added")
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20230927105858.12950-1-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: remove max support speed info in bind operation 2023-08-22T12:48:33+00:00 Linyu Yuan quic_linyyuan@quicinc.com 2023-08-03T09:10:53+00:00 333ab99eab3c6aa7941b898ced3cd754abd20b63 Take ecm_bind() for example, it call gadget_is_{*}speed() API to show gadget max support speed, it is not much help, remove the API usage here is safe. Similar change apply to acm,eem,loopback,ncm,obex,rndis,serial, sourcesink,subset functions. Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> Link: https://lore.kernel.org/r/20230803091053.9714-8-quic_linyyuan@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Take ecm_bind() for example, it call gadget_is_{*}speed() API to show
gadget max support speed, it is not much help, remove the API usage here
is safe.

Similar change apply to acm,eem,loopback,ncm,obex,rndis,serial,
sourcesink,subset functions.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-8-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: add a inline function gether_bitrate() 2023-08-22T12:48:33+00:00 Linyu Yuan quic_linyyuan@quicinc.com 2023-08-03T09:10:48+00:00 8165763f82bd87d742b91ffef2874e7c8d1f6d2b In function ecm_bitrate(), it is not support report bit rate for super speed plus mode, but it can use same bit rate value defined in ncm and rndis. Add a common inline function gether_bitrate() which report different for all possible speeds, it can be used by ecm, ncm and rndis, also remove old function from them. Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> Link: https://lore.kernel.org/r/20230803091053.9714-3-quic_linyyuan@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
In function ecm_bitrate(), it is not support report bit rate for super
speed plus mode, but it can use same bit rate value defined in ncm and
rndis.

Add a common inline function gether_bitrate() which report different for
all possible speeds, it can be used by ecm, ncm and rndis, also remove
old function from them.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-3-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: use working speed to calcaulate network bitrate and qlen 2023-08-22T12:48:33+00:00 Linyu Yuan quic_linyyuan@quicinc.com 2023-08-03T09:10:47+00:00 98102ae1549e3af33359ec3a8e57adafa57b1b01 Take ecm_bitrate() as example, it will be called after gadget device link speed negotiation, consider code if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER), if a gadget device link speed is USB_SPEED_SUPER, gadget_is_superspeed(g) must be true, or not it is a wrong configuration of gadget max support speed. Remove gadget_is_superspeed(g) checking should be safe, and remove other similar operation in ncm, rndis, u_ether. Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com> Link: https://lore.kernel.org/r/20230803091053.9714-2-quic_linyyuan@quicinc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Take ecm_bitrate() as example, it will be called after gadget device
link speed negotiation, consider code
if (gadget_is_superspeed(g) && g->speed == USB_SPEED_SUPER),
if a gadget device link speed is USB_SPEED_SUPER,
gadget_is_superspeed(g) must be true, or not it is a wrong
configuration of gadget max support speed.

Remove gadget_is_superspeed(g) checking should be safe, and remove other
similar operation in ncm, rndis, u_ether.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-2-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
usb: gadget: f_ncm: fix potential NULL ptr deref in ncm_bitrate() 2023-01-17T16:10:34+00:00 Maciej Żenczykowski maze@google.com 2023-01-17T13:18:39+00:00 c6ec929595c7443250b2a4faea988c62019d5cd2 In Google internal bug 265639009 we've received an (as yet) unreproducible crash report from an aarch64 GKI 5.10.149-android13 running device. AFAICT the source code is at: https://android.googlesource.com/kernel/common/+/refs/tags/ASB-2022-12-05_13-5.10 The call stack is: ncm_close() -> ncm_notify() -> ncm_do_notify() with the crash at: ncm_do_notify+0x98/0x270 Code: 79000d0b b9000a6c f940012a f9400269 (b9405d4b) Which I believe disassembles to (I don't know ARM assembly, but it looks sane enough to me...): // halfword (16-bit) store presumably to event->wLength (at offset 6 of struct usb_cdc_notification) 0B 0D 00 79 strh w11, [x8, #6] // word (32-bit) store presumably to req->Length (at offset 8 of struct usb_request) 6C 0A 00 B9 str w12, [x19, #8] // x10 (NULL) was read here from offset 0 of valid pointer x9 // IMHO we're reading 'cdev->gadget' and getting NULL // gadget is indeed at offset 0 of struct usb_composite_dev 2A 01 40 F9 ldr x10, [x9] // loading req->buf pointer, which is at offset 0 of struct usb_request 69 02 40 F9 ldr x9, [x19] // x10 is null, crash, appears to be attempt to read cdev->gadget->max_speed 4B 5D 40 B9 ldr w11, [x10, #0x5c] which seems to line up with ncm_do_notify() case NCM_NOTIFY_SPEED code fragment: event->wLength = cpu_to_le16(8); req->length = NCM_STATUS_BYTECOUNT; /* SPEED_CHANGE data is up/down speeds in bits/sec */ data = req->buf + sizeof *event; data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget)); My analysis of registers and NULL ptr deref crash offset (Unable to handle kernel NULL pointer dereference at virtual address 000000000000005c) heavily suggests that the crash is due to 'cdev->gadget' being NULL when executing: data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget)); which calls: ncm_bitrate(NULL) which then calls: gadget_is_superspeed(NULL) which reads ((struct usb_gadget *)NULL)->max_speed and hits a panic. AFAICT, if I'm counting right, the offset of max_speed is indeed 0x5C. (remember there's a GKI KABI reservation of 16 bytes in struct work_struct) It's not at all clear to me how this is all supposed to work... but returning 0 seems much better than panic-ing... Cc: Felipe Balbi <balbi@kernel.org> Cc: Lorenzo Colitti <lorenzo@google.com> Cc: Carlos Llamas <cmllamas@google.com> Cc: stable@vger.kernel.org Signed-off-by: Maciej Żenczykowski <maze@google.com> Cc: stable <stable@kernel.org> Link: https://lore.kernel.org/r/20230117131839.1138208-1-maze@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
In Google internal bug 265639009 we've received an (as yet) unreproducible
crash report from an aarch64 GKI 5.10.149-android13 running device.

AFAICT the source code is at:
  https://android.googlesource.com/kernel/common/+/refs/tags/ASB-2022-12-05_13-5.10

The call stack is:
  ncm_close() -> ncm_notify() -> ncm_do_notify()
with the crash at:
  ncm_do_notify+0x98/0x270
Code: 79000d0b b9000a6c f940012a f9400269 (b9405d4b)

Which I believe disassembles to (I don't know ARM assembly, but it looks sane enough to me...):

  // halfword (16-bit) store presumably to event->wLength (at offset 6 of struct usb_cdc_notification)
  0B 0D 00 79    strh w11, [x8, #6]

  // word (32-bit) store presumably to req->Length (at offset 8 of struct usb_request)
  6C 0A 00 B9    str  w12, [x19, #8]

  // x10 (NULL) was read here from offset 0 of valid pointer x9
  // IMHO we're reading 'cdev->gadget' and getting NULL
  // gadget is indeed at offset 0 of struct usb_composite_dev
  2A 01 40 F9    ldr  x10, [x9]

  // loading req->buf pointer, which is at offset 0 of struct usb_request
  69 02 40 F9    ldr  x9, [x19]

  // x10 is null, crash, appears to be attempt to read cdev->gadget->max_speed
  4B 5D 40 B9    ldr  w11, [x10, #0x5c]

which seems to line up with ncm_do_notify() case NCM_NOTIFY_SPEED code fragment:

  event->wLength = cpu_to_le16(8);
  req->length = NCM_STATUS_BYTECOUNT;

  /* SPEED_CHANGE data is up/down speeds in bits/sec */
  data = req->buf + sizeof *event;
  data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));

My analysis of registers and NULL ptr deref crash offset
  (Unable to handle kernel NULL pointer dereference at virtual address 000000000000005c)
heavily suggests that the crash is due to 'cdev->gadget' being NULL when executing:
  data[0] = cpu_to_le32(ncm_bitrate(cdev->gadget));
which calls:
  ncm_bitrate(NULL)
which then calls:
  gadget_is_superspeed(NULL)
which reads
  ((struct usb_gadget *)NULL)->max_speed
and hits a panic.

AFAICT, if I'm counting right, the offset of max_speed is indeed 0x5C.
(remember there's a GKI KABI reservation of 16 bytes in struct work_struct)

It's not at all clear to me how this is all supposed to work...
but returning 0 seems much better than panic-ing...

Cc: Felipe Balbi <balbi@kernel.org>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Carlos Llamas <cmllamas@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20230117131839.1138208-1-maze@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>