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Krishna Kurapati 2cb66b62a5 usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs
commit 76c5114682 upstream.

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: 9f6ce4240a ("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>
History 2024-03-01 13:21:50 +01:00
arch x86/alternative: Make custom return thunk unconditional 2024-03-01 13:21:49 +01:00
block blk-iocost: Fix an UBSAN shift-out-of-bounds warning 2024-02-23 08:54:59 +01:00
certs certs/blacklist_hashes.c: fix const confusion in certs blacklist 2022-06-22 14:22:01 +02:00
crypto crypto: api - Disallow identical driver names 2024-02-23 08:54:23 +01:00
Documentation arm64: Subscribe Microsoft Azure Cobalt 100 to ARM Neoverse N2 errata 2024-02-23 08:55:14 +01:00
drivers usb: gadget: ncm: Avoid dropping datagrams of properly parsed NTBs 2024-03-01 13:21:50 +01:00
fs erofs: fix lz4 inplace decompression 2024-03-01 13:21:48 +01:00
include bpf: Remove trace_printk_lock 2024-03-01 13:21:43 +01:00
init rootfs: Fix support for rootfstype= when root= is given 2024-01-25 14:52:48 -08:00
io_uring io_uring/rw: ensure io->bytes_done is always initialized 2024-01-25 14:52:48 -08:00
ipc ipc/sem: Fix dangling sem_array access in semtimedop race 2022-12-08 11:28:45 +01:00
kernel sched/rt: Disallow writing invalid values to sched_rt_period_us 2024-03-01 13:21:43 +01:00
lib crypto: lib/mpi - Fix unexpected pointer access in mpi_ec_init 2024-02-23 08:55:11 +01:00
LICENSES LICENSES/dual/CC-BY-4.0: Git rid of "smart quotes" 2021-07-15 06:31:24 -06:00
mm userfaultfd: fix mmap_changing checking in mfill_atomic_hugetlb 2024-03-01 13:21:43 +01:00
net l2tp: pass correct message length to ip6_append_data 2024-03-01 13:21:48 +01:00
samples samples/hw_breakpoint: fix building without module unloading 2023-09-23 11:10:01 +02:00
scripts scripts/decode_stacktrace.sh: optionally use LLVM utilities 2024-02-23 08:55:13 +01:00
security lsm: fix the logic in security_inode_getsecctx() 2024-02-23 08:55:05 +01:00
sound ALSA: usb-audio: Ignore clock selector errors for single connection 2024-03-01 13:21:45 +01:00
tools Revert "selftests/bpf: Test tail call counting with bpf2bpf and data on stack" 2024-02-23 08:55:15 +01:00
usr usr/include/Makefile: add linux/nfc.h to the compile-test coverage 2022-02-01 17:27:15 +01:00
virt KVM: Grab a reference to KVM for VM and vCPU stats file descriptors 2023-08-03 10:22:40 +02:00
.clang-format clang-format: Update with the latest for_each macro list 2021-05-12 23:32:39 +02:00
.cocciconfig scripts: add Linux .cocciconfig for coccinelle 2016-07-22 12:13:39 +02:00
.get_maintainer.ignore Opt out of scripts/get_maintainer.pl 2019-05-16 10:53:40 -07:00
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore .gitignore: ignore only top-level modules.builtin 2021-05-02 00:43:35 +09:00
.mailmap mailmap: add Andrej Shadura 2021-10-18 20:22:03 -10:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Daniel Drake to credits 2021-09-21 08:34:58 +03:00
Kbuild kbuild: rename hostprogs-y/always to hostprogs/always-y 2020-02-04 01:53:07 +09:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS iio: stx104: Move to addac subdirectory 2023-08-26 14:23:27 +02:00
Makefile Linux 5.15.149 2024-02-23 08:55:16 +01:00
README Drop all 00-INDEX files from Documentation/ 2018-09-09 15:08:58 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.