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Tetsuo Handa 340db7c0a6 USB: cdc-wdm: Fix use after free in service_outstanding_interrupt().
commit 5e5ff0b4b6bcb4d17b7a26ec8bcfc7dd4651684f upstream.

syzbot is reporting UAF at usb_submit_urb() [1], for
service_outstanding_interrupt() is not checking WDM_DISCONNECTING
before calling usb_submit_urb(). Close the race by doing same checks
wdm_read() does upon retry.

Also, while wdm_read() checks WDM_DISCONNECTING with desc->rlock held,
service_interrupt_work() does not hold desc->rlock. Thus, it is possible
that usb_submit_urb() is called from service_outstanding_interrupt() from
service_interrupt_work() after WDM_DISCONNECTING was set and kill_urbs()
 from wdm_disconnect() completed. Thus, move kill_urbs() in
wdm_disconnect() to after cancel_work_sync() (which makes sure that
service_interrupt_work() is no longer running) completed.

Although it seems to be safe to dereference desc->intf->dev in
service_outstanding_interrupt() even if WDM_DISCONNECTING was already set
because desc->rlock or cancel_work_sync() prevents wdm_disconnect() from
reaching list_del() before service_outstanding_interrupt() completes,
let's not emit error message if WDM_DISCONNECTING is set by
wdm_disconnect() while usb_submit_urb() is in progress.

[1] https://syzkaller.appspot.com/bug?extid=9e04e2df4a32fb661daf

Reported-by: syzbot <syzbot+9e04e2df4a32fb661daf@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/620e2ee0-b9a3-dbda-a25b-a93e0ed03ec5@i-love.sakura.ne.jp
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-01-12 20:18:18 +01:00
arch powerpc: Handle .text.{hot,unlikely}.* in linker script 2021-01-12 20:18:17 +01:00
block scsi: block: Do not accept any requests while suspended 2021-01-12 20:18:17 +01:00
certs .gitignore: add SPDX License Identifier 2020-03-25 11:50:48 +01:00
crypto crypto: asym_tpm: correct zero out potential secrets 2021-01-12 20:18:17 +01:00
Documentation dt-bindings: rtc: add reset-source property 2021-01-09 13:46:22 +01:00
drivers USB: cdc-wdm: Fix use after free in service_outstanding_interrupt(). 2021-01-12 20:18:18 +01:00
fs exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:46:24 +01:00
include scsi: block: Do not accept any requests while suspended 2021-01-12 20:18:17 +01:00
init exec: Transform exec_update_mutex into a rw_semaphore 2021-01-09 13:46:24 +01:00
ipc ipc: adjust proc_ipc_sem_dointvec definition to match prototype 2020-09-05 12:14:29 -07:00
kernel workqueue: Kick a worker based on the actual activation of delayed works 2021-01-12 20:18:14 +01:00
lib lib/genalloc: fix the overflow when size is too big 2021-01-12 20:18:16 +01:00
LICENSES LICENSES/deprecated: add Zlib license text 2020-09-16 14:33:49 +02:00
mm mm: memmap defer init doesn't work as expected 2021-01-06 14:56:50 +01:00
net erspan: fix version 1 check in gre_parse_header() 2021-01-12 20:18:12 +01:00
samples samples/bpf: Fix possible hang in xdpsock with multiple threads 2020-12-30 11:53:49 +01:00
scripts depmod: handle the case of /sbin/depmod without /sbin in PATH 2021-01-12 20:18:16 +01:00
security ima: Don't modify file descriptor mode on the fly 2020-12-30 11:54:17 +01:00
sound ALSA: hda/hdmi: Fix incorrect mutex unlock in silent_stream_disable() 2021-01-09 13:46:23 +01:00
tools selftests/vm: fix building protection keys test 2021-01-12 20:18:14 +01:00
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: x86/mmu: Support dirty logging for the TDP MMU 2020-10-23 03:42:13 -04:00
.clang-format RDMA 5.10 pull request 2020-10-17 11:18:18 -07:00
.cocciconfig
.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: docs: ignore sphinx_*/ directories 2020-09-10 10:44:31 -06:00
.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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net 2020-12-10 15:30:13 -08:00
Makefile kbuild: don't hardcode depmod path 2021-01-12 20:18:16 +01:00
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