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Jack Pham e5366bea02 usb: typec: ucsi: Retrieve all the PDOs instead of just the first 4
commit 1f4642b72b upstream.

commit 4dbc6a4ef0 ("usb: typec: ucsi: save power data objects
in PD mode") introduced retrieval of the PDOs when connected to a
PD-capable source. But only the first 4 PDOs are received since
that is the maximum number that can be fetched at a time given the
MESSAGE_IN length limitation (16 bytes). However, as per the PD spec
a connected source may advertise up to a maximum of 7 PDOs.

If such a source is connected it's possible the PPM could have
negotiated a power contract with one of the PDOs at index greater
than 4, and would be reflected in the request data object's (RDO)
object position field. This would result in an out-of-bounds access
when the rdo_index() is used to index into the src_pdos array in
ucsi_psy_get_voltage_now().

With the help of the UBSAN -fsanitize=array-bounds checker enabled
this exact issue is revealed when connecting to a PD source adapter
that advertise 5 PDOs and the PPM enters a contract having selected
the 5th one.

[  151.545106][   T70] Unexpected kernel BRK exception at EL1
[  151.545112][   T70] Internal error: BRK handler: f2005512 [#1] PREEMPT SMP
...
[  151.545499][   T70] pc : ucsi_psy_get_prop+0x208/0x20c
[  151.545507][   T70] lr : power_supply_show_property+0xc0/0x328
...
[  151.545542][   T70] Call trace:
[  151.545544][   T70]  ucsi_psy_get_prop+0x208/0x20c
[  151.545546][   T70]  power_supply_uevent+0x1a4/0x2f0
[  151.545550][   T70]  dev_uevent+0x200/0x384
[  151.545555][   T70]  kobject_uevent_env+0x1d4/0x7e8
[  151.545557][   T70]  power_supply_changed_work+0x174/0x31c
[  151.545562][   T70]  process_one_work+0x244/0x6f0
[  151.545564][   T70]  worker_thread+0x3e0/0xa64

We can resolve this by instead retrieving and storing up to the
maximum of 7 PDOs in the con->src_pdos array. This would involve
two calls to the GET_PDOS command.

Fixes: 992a60ed0d ("usb: typec: ucsi: register with power_supply class")
Fixes: 4dbc6a4ef0 ("usb: typec: ucsi: save power data objects in PD mode")
Cc: stable@vger.kernel.org
Reported-and-tested-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Link: https://lore.kernel.org/r/20210503074611.30973-1-jackp@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-05-19 10:13:15 +02:00
arch KVM: x86: Prevent deadlock against tk_core.seq 2021-05-19 10:13:12 +02:00
block blk-mq: Swap two calls in blk_mq_exit_queue() 2021-05-19 10:13:14 +02:00
certs certs: Fix blacklist flag type confusion 2021-03-04 11:37:59 +01:00
crypto async_xor: increase src_offs when dropping destination page 2021-05-14 09:49:59 +02:00
Documentation kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
drivers usb: typec: ucsi: Retrieve all the PDOs instead of just the first 4 2021-05-19 10:13:15 +02:00
fs f2fs: compress: fix to assign cc.cluster_idx correctly 2021-05-19 10:13:14 +02:00
include kyber: fix out of bounds access when preempted 2021-05-19 10:13:13 +02:00
init seccomp: Fix CONFIG tests for Seccomp_filters 2021-05-14 09:50:24 +02:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel kernel/resource: make walk_mem_res() find all busy IORESOURCE_MEM resources 2021-05-19 10:13:09 +02:00
lib kasan: fix unit tests with CONFIG_UBSAN_LOCAL_BOUNDS enabled 2021-05-19 10:13:11 +02:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm/hugetlb: fix F_SEAL_FUTURE_WRITE 2021-05-19 10:13:11 +02:00
net mptcp: fix splat when closing unaccepted socket 2021-05-19 10:13:10 +02:00
samples samples/bpf: Fix broken tracex1 due to kprobe argument change 2021-05-19 10:12:57 +02:00
scripts kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
security KEYS: trusted: Fix memory leak on object td 2021-05-19 10:12:50 +02:00
sound ASoC: rt286: Make RT286_SET_GPIO_* readable and writable 2021-05-19 10:13:00 +02:00
tools perf tools: Fix dynamic libbpf link 2021-05-19 10:13:13 +02:00
usr Merge branch 'work.fdpic' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2020-08-07 13:29:39 -07:00
virt kvm: exit halt polling on need_resched() as well 2021-05-19 10:13:12 +02:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: use 'dts' diff driver for dts files 2019-12-04 19:44:11 -08:00
.gitignore kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
.mailmap mailmap: add two more addresses of Uwe Kleine-König 2020-12-06 10:19:07 -08:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: Move Jason Cooper to CREDITS 2020-11-30 10:20:34 +01:00
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 f2fs: move ioctl interface definitions to separated file 2021-05-19 10:13:00 +02:00
Makefile kbuild: generate Module.symvers only when vmlinux exists 2021-05-19 10:12:59 +02:00
README

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.