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Matias Karhumaa 0fdb922d0e Bluetooth: Check state in l2cap_disconnect_rsp
[ Upstream commit 28261da8a2 ]

Because of both sides doing L2CAP disconnection at the same time, it
was possible to receive L2CAP Disconnection Response with CID that was
already freed. That caused problems if CID was already reused and L2CAP
Connection Request with same CID was sent out. Before this patch kernel
deleted channel context regardless of the state of the channel.

Example where leftover Disconnection Response (frame #402) causes local
device to delete L2CAP channel which was not yet connected. This in
turn confuses remote device's stack because same CID is re-used without
properly disconnecting.

Btmon capture before patch:
** snip **
> ACL Data RX: Handle 43 flags 0x02 dlen 8                #394 [hci1] 10.748949
      Channel: 65 len 4 [PSM 3 mode 0] {chan 2}
      RFCOMM: Disconnect (DISC) (0x43)
         Address: 0x03 cr 1 dlci 0x00
         Control: 0x53 poll/final 1
         Length: 0
         FCS: 0xfd
< ACL Data TX: Handle 43 flags 0x00 dlen 8                #395 [hci1] 10.749062
      Channel: 65 len 4 [PSM 3 mode 0] {chan 2}
      RFCOMM: Unnumbered Ack (UA) (0x63)
         Address: 0x03 cr 1 dlci 0x00
         Control: 0x73 poll/final 1
         Length: 0
         FCS: 0xd7
< ACL Data TX: Handle 43 flags 0x00 dlen 12               #396 [hci1] 10.749073
      L2CAP: Disconnection Request (0x06) ident 17 len 4
        Destination CID: 65
        Source CID: 65
> HCI Event: Number of Completed Packets (0x13) plen 5    #397 [hci1] 10.752391
        Num handles: 1
        Handle: 43
        Count: 1
> HCI Event: Number of Completed Packets (0x13) plen 5    #398 [hci1] 10.753394
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 12               #399 [hci1] 10.756499
      L2CAP: Disconnection Request (0x06) ident 26 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 12               #400 [hci1] 10.756548
      L2CAP: Disconnection Response (0x07) ident 26 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 12               #401 [hci1] 10.757459
      L2CAP: Connection Request (0x02) ident 18 len 4
        PSM: 1 (0x0001)
        Source CID: 65
> ACL Data RX: Handle 43 flags 0x02 dlen 12               #402 [hci1] 10.759148
      L2CAP: Disconnection Response (0x07) ident 17 len 4
        Destination CID: 65
        Source CID: 65
= bluetoothd: 00:1E:AB:4C:56:54: error updating services: Input/o..   10.759447
> HCI Event: Number of Completed Packets (0x13) plen 5    #403 [hci1] 10.759386
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 12               #404 [hci1] 10.760397
      L2CAP: Connection Request (0x02) ident 27 len 4
        PSM: 3 (0x0003)
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 16               #405 [hci1] 10.760441
      L2CAP: Connection Response (0x03) ident 27 len 8
        Destination CID: 65
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
< ACL Data TX: Handle 43 flags 0x00 dlen 27               #406 [hci1] 10.760449
      L2CAP: Configure Request (0x04) ident 19 len 19
        Destination CID: 65
        Flags: 0x0000
        Option: Maximum Transmission Unit (0x01) [mandatory]
          MTU: 1013
        Option: Retransmission and Flow Control (0x04) [mandatory]
          Mode: Basic (0x00)
          TX window size: 0
          Max transmit: 0
          Retransmission timeout: 0
          Monitor timeout: 0
          Maximum PDU size: 0
> HCI Event: Number of Completed Packets (0x13) plen 5    #407 [hci1] 10.761399
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 16               #408 [hci1] 10.762942
      L2CAP: Connection Response (0x03) ident 18 len 8
        Destination CID: 66
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
*snip*

Similar case after the patch:
*snip*
> ACL Data RX: Handle 43 flags 0x02 dlen 8            #22702 [hci0] 1664.411056
      Channel: 65 len 4 [PSM 3 mode 0] {chan 3}
      RFCOMM: Disconnect (DISC) (0x43)
         Address: 0x03 cr 1 dlci 0x00
         Control: 0x53 poll/final 1
         Length: 0
         FCS: 0xfd
< ACL Data TX: Handle 43 flags 0x00 dlen 8            #22703 [hci0] 1664.411136
      Channel: 65 len 4 [PSM 3 mode 0] {chan 3}
      RFCOMM: Unnumbered Ack (UA) (0x63)
         Address: 0x03 cr 1 dlci 0x00
         Control: 0x73 poll/final 1
         Length: 0
         FCS: 0xd7
< ACL Data TX: Handle 43 flags 0x00 dlen 12           #22704 [hci0] 1664.411143
      L2CAP: Disconnection Request (0x06) ident 11 len 4
        Destination CID: 65
        Source CID: 65
> HCI Event: Number of Completed Pac.. (0x13) plen 5  #22705 [hci0] 1664.414009
        Num handles: 1
        Handle: 43
        Count: 1
> HCI Event: Number of Completed Pac.. (0x13) plen 5  #22706 [hci0] 1664.415007
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 12           #22707 [hci0] 1664.418674
      L2CAP: Disconnection Request (0x06) ident 17 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 12           #22708 [hci0] 1664.418762
      L2CAP: Disconnection Response (0x07) ident 17 len 4
        Destination CID: 65
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 12           #22709 [hci0] 1664.421073
      L2CAP: Connection Request (0x02) ident 12 len 4
        PSM: 1 (0x0001)
        Source CID: 65
> ACL Data RX: Handle 43 flags 0x02 dlen 12           #22710 [hci0] 1664.421371
      L2CAP: Disconnection Response (0x07) ident 11 len 4
        Destination CID: 65
        Source CID: 65
> HCI Event: Number of Completed Pac.. (0x13) plen 5  #22711 [hci0] 1664.424082
        Num handles: 1
        Handle: 43
        Count: 1
> HCI Event: Number of Completed Pac.. (0x13) plen 5  #22712 [hci0] 1664.425040
        Num handles: 1
        Handle: 43
        Count: 1
> ACL Data RX: Handle 43 flags 0x02 dlen 12           #22713 [hci0] 1664.426103
      L2CAP: Connection Request (0x02) ident 18 len 4
        PSM: 3 (0x0003)
        Source CID: 65
< ACL Data TX: Handle 43 flags 0x00 dlen 16           #22714 [hci0] 1664.426186
      L2CAP: Connection Response (0x03) ident 18 len 8
        Destination CID: 66
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
< ACL Data TX: Handle 43 flags 0x00 dlen 27           #22715 [hci0] 1664.426196
      L2CAP: Configure Request (0x04) ident 13 len 19
        Destination CID: 65
        Flags: 0x0000
        Option: Maximum Transmission Unit (0x01) [mandatory]
          MTU: 1013
        Option: Retransmission and Flow Control (0x04) [mandatory]
          Mode: Basic (0x00)
          TX window size: 0
          Max transmit: 0
          Retransmission timeout: 0
          Monitor timeout: 0
          Maximum PDU size: 0
> ACL Data RX: Handle 43 flags 0x02 dlen 16           #22716 [hci0] 1664.428804
      L2CAP: Connection Response (0x03) ident 12 len 8
        Destination CID: 66
        Source CID: 65
        Result: Connection successful (0x0000)
        Status: No further information available (0x0000)
*snip*

Fix is to check that channel is in state BT_DISCONN before deleting the
channel.

This bug was found while fuzzing Bluez's OBEX implementation using
Synopsys Defensics.

Reported-by: Matti Kamunen <matti.kamunen@synopsys.com>
Reported-by: Ari Timonen <ari.timonen@synopsys.com>
Signed-off-by: Matias Karhumaa <matias.karhumaa@gmail.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-07-26 09:14:16 +02:00
arch x86/build: Add 'set -e' to mkcapflags.sh to delete broken capflags.c 2019-07-26 09:14:11 +02:00
block blk-iolatency: only account submitted bios 2019-07-26 09:14:09 +02:00
certs export.h: remove VMLINUX_SYMBOL() and VMLINUX_SYMBOL_STR() 2018-08-22 23:21:44 +09:00
crypto crypto: asymmetric_keys - select CRYPTO_HASH where needed 2019-07-26 09:14:13 +02:00
Documentation x86/atomic: Fix smp_mb__{before,after}_atomic() 2019-07-26 09:14:08 +02:00
drivers Bluetooth: Add new 13d3:3501 QCA_ROME device 2019-07-26 09:14:16 +02:00
firmware kbuild: remove all dummy assignments to obj- 2017-11-18 11:46:06 +09:00
fs blkcg, writeback: dead memcgs shouldn't contribute to writeback ownership arbitration 2019-07-26 09:14:08 +02:00
include rxrpc: Fix oops in tracepoint 2019-07-26 09:14:15 +02:00
init initramfs: free initrd memory if opening /initrd.image fails 2019-06-15 11:54:01 +02:00
ipc ipc: prevent lockup on alloc_msg and free_msg 2019-06-15 11:54:00 +02:00
kernel timer_list: Guard procfs specific code 2019-07-26 09:14:10 +02:00
lib rslib: Fix handling of of caller provided syndrome 2019-07-26 09:14:12 +02:00
LICENSES LICENSES: Remove CC-BY-SA-4.0 license text 2018-10-18 11:28:50 +02:00
mm mm/vmscan.c: prevent useless kswapd loops 2019-07-10 09:53:44 +02:00
net Bluetooth: Check state in l2cap_disconnect_rsp 2019-07-26 09:14:16 +02:00
samples samples, bpf: suppress compiler warning 2019-07-14 08:11:04 +02:00
scripts scripts/decode_stacktrace.sh: prefix addr2line with $CROSS_COMPILE 2019-07-10 09:53:39 +02:00
security selinux: fix empty write to keycreate file 2019-07-26 09:14:07 +02:00
sound ASoC: Intel: hdac_hdmi: Set ops to NULL on remove 2019-07-26 09:14:12 +02:00
tools perf tests: Fix record+probe_libc_inet_pton.sh for powerpc64 2019-07-26 09:14:16 +02:00
usr initramfs: move gen_initramfs_list.sh from scripts/ to usr/ 2018-08-22 23:21:44 +09:00
virt KVM: arm/arm64: vgic: Fix kvm_device leak in vgic_its_destroy 2019-07-14 08:11:10 +02:00
.clang-format clang-format: Set IndentWrappedFunctionNames false 2018-08-01 18:38:51 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore Kbuild updates for v4.17 (2nd) 2018-04-15 17:21:30 -07:00
.mailmap libnvdimm-for-4.19_misc 2018-08-25 18:13:10 -07:00
COPYING COPYING: use the new text with points to the license files 2018-03-23 12:41:45 -06:00
CREDITS 9p: remove Ron Minnich from MAINTAINERS 2018-08-17 16:20:26 -07:00
Kbuild Kbuild updates for v4.15 2017-11-17 17:45:29 -08:00
Kconfig kconfig: move the "Executable file formats" menu to fs/Kconfig.binfmt 2018-08-02 08:06:55 +09:00
MAINTAINERS platform/x86: Add Intel AtomISP2 dummy / power-management driver 2019-04-20 09:16:02 +02:00
Makefile Linux 4.19.60 2019-07-21 09:03:18 +02:00
README Docs: Added a pointer to the formatted docs to README 2018-03-21 09:02:53 -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
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    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.
See Documentation/00-INDEX for a list of what is contained in each file.

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.