When a BLE peripheral sends an L2CAP Connection Parameter Update Request
the processing path is:
process_pending_rx() [takes conn->lock]
l2cap_le_sig_channel()
l2cap_conn_param_update_req()
hci_le_conn_update() [takes hdev->lock]
Meanwhile other code paths take the locks in the opposite order:
l2cap_chan_connect() [takes hdev->lock]
...
mutex_lock(&conn->lock)
l2cap_conn_ready() [hdev->lock via hci_cb_list_lock]
...
mutex_lock(&conn->lock)
This is a classic AB/BA deadlock which lockdep reports as a circular
locking dependency when connecting a BLE MIDI keyboard (Carry-On FC-49).
Fix this by making hci_le_conn_update() defer the HCI command through
hci_cmd_sync_queue() so it no longer needs to take hdev->lock in the
caller context. The sync callback uses __hci_cmd_sync_status_sk() to
wait for the HCI_EV_LE_CONN_UPDATE_COMPLETE event, then updates the
stored connection parameters (hci_conn_params) and notifies userspace
(mgmt_new_conn_param) only after the controller has confirmed the update.
A reference on hci_conn is held via hci_conn_get()/hci_conn_put() for
the lifetime of the queued work to prevent use-after-free, and
hci_conn_valid() is checked before proceeding in case the connection was
removed while the work was pending. The hci_dev_lock is held across
hci_conn_valid() and all conn field accesses to prevent a concurrent
disconnect from invalidating the connection mid-use.
Fixes: f044eb0524 ("Bluetooth: Store latency and supervision timeout in connection params")
Signed-off-by: Mikhail Gavrilov <mikhail.v.gavrilov@gmail.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
The L2CAP specification states that if more than one channel is being
reconfigured, the MPS shall not be decreased. The current check has
two issues:
1) The comparison uses >= (greater-than-or-equal), which incorrectly
rejects reconfiguration requests where the MPS stays the same.
Since the spec says MPS "shall be greater than or equal to the
current MPS", only a strict decrease (remote_mps > mps) should be
rejected. Keeping the same MPS is valid.
2) The multi-channel guard uses `&& i` (loop index) to approximate
"more than one channel", but this incorrectly allows MPS decrease
for the first channel (i==0) even when multiple channels are being
reconfigured. Replace with `&& num_scid > 1` which correctly
checks whether the request covers more than one channel.
Fixes: 7accb1c432 ("Bluetooth: L2CAP: Fix invalid response to L2CAP_ECRED_RECONF_REQ")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_ecred_reconf_rsp() calls l2cap_chan_del() without holding
l2cap_chan_lock(). Every other l2cap_chan_del() caller in the file
acquires the lock first. A remote BLE device can send a crafted
L2CAP ECRED reconfiguration response to corrupt the channel list
while another thread is iterating it.
Add l2cap_chan_hold() and l2cap_chan_lock() before l2cap_chan_del(),
and l2cap_chan_unlock() and l2cap_chan_put() after, matching the
pattern used in l2cap_ecred_conn_rsp() and l2cap_conn_del().
Fixes: 15f02b9105 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Dudu Lu <phx0fer@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Core 6.0, Vol 3, Part A, 3.4.3:
"... If the payload size of any K-frame exceeds the receiver's MPS, the
receiver shall disconnect the channel..."
This fixes L2CAP/LE/CFC/BV-27-C (running together with 'l2test -r -P
0x0027 -V le_public -I 100').
Signed-off-by: Christian Eggers <ceggers@arri.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-by: Christian Eggers <ceggers@arri.de>
l2cap_config_req() processes CONFIG_REQ for channels in BT_CONNECTED
state to support L2CAP reconfiguration (e.g. MTU changes). However,
since both CONF_INPUT_DONE and CONF_OUTPUT_DONE are already set from
the initial configuration, the reconfiguration path falls through to
l2cap_ertm_init(), which re-initializes tx_q, srej_q, srej_list, and
retrans_list without freeing the previous allocations and sets
chan->sdu to NULL without freeing the existing skb. This leaks all
previously allocated ERTM resources.
Additionally, l2cap_parse_conf_req() does not validate the minimum
value of remote_mps derived from the RFC max_pdu_size option. A zero
value propagates to l2cap_segment_sdu() where pdu_len becomes zero,
causing the while loop to never terminate since len is never
decremented, exhausting all available memory.
Fix the double-init by skipping l2cap_ertm_init() and
l2cap_chan_ready() when the channel is already in BT_CONNECTED state,
while still allowing the reconfiguration parameters to be updated
through l2cap_parse_conf_req(). Also add a pdu_len zero check in
l2cap_segment_sdu() as a safeguard.
Fixes: 96298f6401 ("Bluetooth: L2CAP: handle l2cap config request during open state")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_conn_del() calls cancel_delayed_work_sync() for both info_timer
and id_addr_timer while holding conn->lock. However, the work functions
l2cap_info_timeout() and l2cap_conn_update_id_addr() both acquire
conn->lock, creating a potential AB-BA deadlock if the work is already
executing when l2cap_conn_del() takes the lock.
Move the work cancellations before acquiring conn->lock and use
disable_delayed_work_sync() to additionally prevent the works from
being rearmed after cancellation, consistent with the pattern used in
hci_conn_del().
Fixes: ab4eedb790 ("Bluetooth: L2CAP: Fix corrupted list in hci_chan_del")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
When the L2CAP channel mode is L2CAP_MODE_ERTM/L2CAP_MODE_STREAMING,
l2cap_publish_rx_avail will be called and le flow credits will be sent in
l2cap_chan_rx_avail, even though the link type is ACL.
The logs in question as follows:
> ACL Data RX: Handle 129 flags 0x02 dlen 12
L2CAP: Unknown (0x16) ident 4 len 4
40 00 ed 05
< ACL Data TX: Handle 129 flags 0x00 dlen 10
L2CAP: Command Reject (0x01) ident 4 len 2
Reason: Command not understood (0x0000)
Bluetooth: Unknown BR/EDR signaling command 0x16
Bluetooth: Wrong link type (-22)
Fixes: ce60b9231b ("Bluetooth: compute LE flow credits based on recvbuf space")
Signed-off-by: Zhang Chen <zhangchen01@kylinos.cn>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This attempt to fix regressions caused by reusing ident which apparently
is not handled well on certain stacks causing the stack to not respond to
requests, so instead of simple returning the first unallocated id this
stores the last used tx_ident and then attempt to use the next until all
available ids are exausted and then cycle starting over to 1.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=221120
Link: https://bugzilla.kernel.org/show_bug.cgi?id=221177
Fixes: 6c3ea155e5 ("Bluetooth: L2CAP: Fix not tracking outstanding TX ident")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-by: Christian Eggers <ceggers@arri.de>
l2cap_ecred_data_rcv() reads the SDU length field from skb->data using
get_unaligned_le16() without first verifying that skb contains at least
L2CAP_SDULEN_SIZE (2) bytes. When skb->len is less than 2, this reads
past the valid data in the skb.
The ERTM reassembly path correctly calls pskb_may_pull() before reading
the SDU length (l2cap_reassemble_sdu, L2CAP_SAR_START case). Apply the
same validation to the Enhanced Credit Based Flow Control data path.
Fixes: aac23bf636 ("Bluetooth: Implement LE L2CAP reassembly")
Signed-off-by: Hyunwoo Kim <imv4bel@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Syzbot reported a KASAN stack-out-of-bounds read in l2cap_build_cmd()
that is triggered by a malformed Enhanced Credit Based Connection Request.
The vulnerability stems from l2cap_ecred_conn_req(). The function allocates
a local stack buffer (`pdu`) designed to hold a maximum of 5 Source Channel
IDs (SCIDs), totaling 18 bytes. When an attacker sends a request with more
than 5 SCIDs, the function calculates `rsp_len` based on this unvalidated
`cmd_len` before checking if the number of SCIDs exceeds
L2CAP_ECRED_MAX_CID.
If the SCID count is too high, the function correctly jumps to the
`response` label to reject the packet, but `rsp_len` retains the
attacker's oversized value. Consequently, l2cap_send_cmd() is instructed
to read past the end of the 18-byte `pdu` buffer, triggering a
KASAN panic.
Fix this by moving the assignment of `rsp_len` to after the `num_scid`
boundary check. If the packet is rejected, `rsp_len` will safely
remain 0, and the error response will only read the 8-byte base header
from the stack.
Fixes: c28d2bff70 ("Bluetooth: L2CAP: Fix result of L2CAP_ECRED_CONN_RSP when MTU is too short")
Reported-by: syzbot+b7f3e7d9a596bf6a63e3@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=b7f3e7d9a596bf6a63e3
Tested-by: syzbot+b7f3e7d9a596bf6a63e3@syzkaller.appspotmail.com
Signed-off-by: Minseo Park <jacob.park.9436@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_information_rsp() checks that cmd_len covers the fixed
l2cap_info_rsp header (type + result, 4 bytes) but then reads
rsp->data without verifying that the payload is present:
- L2CAP_IT_FEAT_MASK calls get_unaligned_le32(rsp->data), which reads
4 bytes past the header (needs cmd_len >= 8).
- L2CAP_IT_FIXED_CHAN reads rsp->data[0], 1 byte past the header
(needs cmd_len >= 5).
A truncated L2CAP_INFO_RSP with result == L2CAP_IR_SUCCESS triggers an
out-of-bounds read of adjacent skb data.
Guard each data access with the required payload length check. If the
payload is too short, skip the read and let the state machine complete
with safe defaults (feat_mask and remote_fixed_chan remain zero from
kzalloc), so the info timer cleanup and l2cap_conn_start() still run
and the connection is not stalled.
Fixes: 4e8402a3f8 ("[Bluetooth] Retrieve L2CAP features mask on connection setup")
Cc: stable@vger.kernel.org
Signed-off-by: Lukas Johannes Möller <research@johannes-moeller.dev>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_ecred_reconf_rsp() casts the incoming data to struct
l2cap_ecred_conn_rsp (the ECRED *connection* response, 8 bytes with
result at offset 6) instead of struct l2cap_ecred_reconf_rsp (2 bytes
with result at offset 0).
This causes two problems:
- The sizeof(*rsp) length check requires 8 bytes instead of the
correct 2, so valid L2CAP_ECRED_RECONF_RSP packets are rejected
with -EPROTO.
- rsp->result reads from offset 6 instead of offset 0, returning
wrong data when the packet is large enough to pass the check.
Fix by using the correct type. Also pass the already byte-swapped
result variable to BT_DBG instead of the raw __le16 field.
Fixes: 15f02b9105 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Cc: stable@vger.kernel.org
Signed-off-by: Lukas Johannes Möller <research@johannes-moeller.dev>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Currently the code attempts to accept requests regardless of the
command identifier which may cause multiple requests to be marked
as pending (FLAG_DEFER_SETUP) which can cause more than
L2CAP_ECRED_MAX_CID(5) to be allocated in l2cap_ecred_rsp_defer
causing an overflow.
The spec is quite clear that the same identifier shall not be used on
subsequent requests:
'Within each signaling channel a different Identifier shall be used
for each successive request or indication.'
https://www.bluetooth.com/wp-content/uploads/Files/Specification/HTML/Core-62/out/en/host/logical-link-control-and-adaptation-protocol-specification.html#UUID-32a25a06-4aa4-c6c7-77c5-dcfe3682355d
So this attempts to check if there are any channels pending with the
same identifier and rejects if any are found.
Fixes: 15f02b9105 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Reported-by: Yiming Qian <yimingqian591@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
After commit ab4eedb790 ("Bluetooth: L2CAP: Fix corrupted list in
hci_chan_del"), l2cap_conn_del() uses conn->lock to protect access to
conn->users. However, l2cap_register_user() and l2cap_unregister_user()
don't use conn->lock, creating a race condition where these functions can
access conn->users and conn->hchan concurrently with l2cap_conn_del().
This can lead to use-after-free and list corruption bugs, as reported
by syzbot.
Fix this by changing l2cap_register_user() and l2cap_unregister_user()
to use conn->lock instead of hci_dev_lock(), ensuring consistent locking
for the l2cap_conn structure.
Reported-by: syzbot+14b6d57fb728e27ce23c@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=14b6d57fb728e27ce23c
Fixes: ab4eedb790 ("Bluetooth: L2CAP: Fix corrupted list in hci_chan_del")
Signed-off-by: Shaurya Rane <ssrane_b23@ee.vjti.ac.in>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Core 6.0, Vol 3, Part A, 3.4.3:
"... If the sum of the payload sizes for the K-frames exceeds the
specified SDU length, the receiver shall disconnect the channel."
This fixes L2CAP/LE/CFC/BV-27-C (running together with 'l2test -r -P
0x0027 -V le_public').
Fixes: aac23bf636 ("Bluetooth: Implement LE L2CAP reassembly")
Signed-off-by: Christian Eggers <ceggers@arri.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Core 6.0, Vol 3, Part A, 3.4.3:
"If the SDU length field value exceeds the receiver's MTU, the receiver
shall disconnect the channel..."
This fixes L2CAP/LE/CFC/BV-26-C (running together with 'l2test -r -P
0x0027 -V le_public -I 100').
Fixes: aac23bf636 ("Bluetooth: Implement LE L2CAP reassembly")
Signed-off-by: Christian Eggers <ceggers@arri.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This adds a check for encryption key size upon receiving
L2CAP_LE_CONN_REQ which is required by L2CAP/LE/CFC/BV-15-C which
expects L2CAP_CR_LE_BAD_KEY_SIZE.
Link: https://lore.kernel.org/linux-bluetooth/5782243.rdbgypaU67@n9w6sw14/
Fixes: 27e2d4c8d2 ("Bluetooth: Add basic LE L2CAP connect request receiving support")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-by: Christian Eggers <ceggers@arri.de>
Upon receiving L2CAP_ECRED_CONN_REQ the given MTU shall be checked
against the suggested MTU of the listening socket as that is required
by the likes of PTS L2CAP/ECFC/BV-27-C test which expects
L2CAP_CR_LE_UNACCEPT_PARAMS if the MTU is lowers than socket omtu.
In order to be able to set chan->omtu the code now allows setting
setsockopt(BT_SNDMTU), but it is only allowed when connection has not
been stablished since there is no procedure to reconfigure the output
MTU.
Link: https://github.com/bluez/bluez/issues/1895
Fixes: 15f02b9105 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Similar to 03dba9cea7 ("Bluetooth: L2CAP: Fix not responding with
L2CAP_CR_LE_ENCRYPTION") the result code L2CAP_CR_LE_ENCRYPTION shall
be used when BT_SECURITY_MEDIUM is set since that means security mode 2
which mean it doesn't require authentication which results in
qualification test L2CAP/ECFC/BV-32-C failing.
Link: https://github.com/bluez/bluez/issues/1871
Fixes: 15f02b9105 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Test L2CAP/ECFC/BV-26-C expect the response to L2CAP_ECRED_CONN_REQ with
and MTU value < L2CAP_ECRED_MIN_MTU (64) to be L2CAP_CR_LE_INVALID_PARAMS
rather than L2CAP_CR_LE_UNACCEPT_PARAMS.
Also fix not including the correct number of CIDs in the response since
the spec requires all CIDs being rejected to be included in the
response.
Link: https://github.com/bluez/bluez/issues/1868
Fixes: 15f02b9105 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This fixes responding with an invalid result caused by checking the
wrong size of CID which should have been (cmd_len - sizeof(*req)) and
on top of it the wrong result was use L2CAP_CR_LE_INVALID_PARAMS which
is invalid/reserved for reconf when running test like L2CAP/ECFC/BI-03-C:
> ACL Data RX: Handle 64 flags 0x02 dlen 14
LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 2 len 6
MTU: 64
MPS: 64
Source CID: 64
< ACL Data TX: Handle 64 flags 0x00 dlen 10
LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2
! Result: Reserved (0x000c)
Result: Reconfiguration failed - one or more Destination CIDs invalid (0x0003)
Fiix L2CAP/ECFC/BI-04-C which expects L2CAP_RECONF_INVALID_MPS (0x0002)
when more than one channel gets its MPS reduced:
> ACL Data RX: Handle 64 flags 0x02 dlen 16
LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 2 len 8
MTU: 264
MPS: 99
Source CID: 64
! Source CID: 65
< ACL Data TX: Handle 64 flags 0x00 dlen 10
LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2
! Result: Reconfiguration successful (0x0000)
Result: Reconfiguration failed - reduction in size of MPS not allowed for more than one channel at a time (0x0002)
Fix L2CAP/ECFC/BI-05-C when SCID is invalid (85 unconnected):
> ACL Data RX: Handle 64 flags 0x02 dlen 14
LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 2 len 6
MTU: 65
MPS: 64
! Source CID: 85
< ACL Data TX: Handle 64 flags 0x00 dlen 10
LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2
! Result: Reconfiguration successful (0x0000)
Result: Reconfiguration failed - one or more Destination CIDs invalid (0x0003)
Fix L2CAP/ECFC/BI-06-C when MPS < L2CAP_ECRED_MIN_MPS (64):
> ACL Data RX: Handle 64 flags 0x02 dlen 14
LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 2 len 6
MTU: 672
! MPS: 63
Source CID: 64
< ACL Data TX: Handle 64 flags 0x00 dlen 10
LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2
! Result: Reconfiguration failed - reduction in size of MPS not allowed for more than one channel at a time (0x0002)
Result: Reconfiguration failed - other unacceptable parameters (0x0004)
Fix L2CAP/ECFC/BI-07-C when MPS reduced for more than one channel:
> ACL Data RX: Handle 64 flags 0x02 dlen 16
LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 3 len 8
MTU: 84
! MPS: 71
Source CID: 64
! Source CID: 65
< ACL Data TX: Handle 64 flags 0x00 dlen 10
LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2
! Result: Reconfiguration successful (0x0000)
Result: Reconfiguration failed - reduction in size of MPS not allowed for more than one channel at a time (0x0002)
Link: https://github.com/bluez/bluez/issues/1865
Fixes: 15f02b9105 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
This attempts to proper track outstanding request by using struct ida
and allocating from it in l2cap_get_ident using ida_alloc_range which
would reuse ids as they are free, then upon completion release
the id using ida_free.
This fixes the qualification test case L2CAP/COS/CED/BI-29-C which
attempts to check if the host stack is able to work after 256 attempts
to connect which requires Ident field to use the full range of possible
values in order to pass the test.
Link: https://github.com/bluez/bluez/issues/1829
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
The hdev lock/lookup/unlock/use pattern in the packet RX path doesn't
ensure hci_conn* is not concurrently modified/deleted. This locking
appears to be leftover from before conn_hash started using RCU
commit bf4c632524 ("Bluetooth: convert conn hash to RCU")
and not clear if it had purpose since then.
Currently, there are code paths that delete hci_conn* from elsewhere
than the ordered hdev->workqueue where the RX work runs in. E.g.
commit 5af1f84ed1 ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync")
introduced some of these, and there probably were a few others before
it. It's better to do the locking so that even if these run
concurrently no UAF is possible.
Move the lookup of hci_conn and associated socket-specific conn to
protocol recv handlers, and do them within a single critical section
to cover hci_conn* usage and lookup.
syzkaller has reported a crash that appears to be this issue:
[Task hdev->workqueue] [Task 2]
hci_disconnect_all_sync
l2cap_recv_acldata(hcon)
hci_conn_get(hcon)
hci_abort_conn_sync(hcon)
hci_dev_lock
hci_dev_lock
hci_conn_del(hcon)
v-------------------------------- hci_dev_unlock
hci_conn_put(hcon)
conn = hcon->l2cap_data (UAF)
Fixes: 5af1f84ed1 ("Bluetooth: hci_sync: Fix UAF on hci_abort_conn_sync")
Reported-by: syzbot+d32d77220b92eddd89ad@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d32d77220b92eddd89ad
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_chan_put() is exported, so export also l2cap_chan_hold() for
modules.
l2cap_chan_hold() has use case in net/bluetooth/6lowpan.c
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This reverts commit c9d84da18d. It
replaces in L2CAP calls to msecs_to_jiffies() to secs_to_jiffies()
and updates the constants accordingly. But the constants are also
used in LCAP Configure Request and L2CAP Configure Response which
expect values in milliseconds.
This may prevent correct usage of L2CAP channel.
To fix it, keep those constants in milliseconds and so revert this
change.
Fixes: c9d84da18d ("Bluetooth: L2CAP: convert timeouts to secs_to_jiffies()")
Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Configuration request only configure the incoming direction of the peer
initiating the request, so using the MTU is the other direction shall
not be used, that said the spec allows the peer responding to adjust:
Bluetooth Core 6.1, Vol 3, Part A, Section 4.5
'Each configuration parameter value (if any is present) in an
L2CAP_CONFIGURATION_RSP packet reflects an ‘adjustment’ to a
configuration parameter value that has been sent (or, in case of
default values, implied) in the corresponding
L2CAP_CONFIGURATION_REQ packet.'
That said adjusting the MTU in the response shall be limited to ERTM
channels only as for older modes the remote stack may not be able to
detect the adjustment causing it to silently drop packets.
Link: https://github.com/bluez/bluez/issues/1422
Link: https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/issues/149
Link: https://gitlab.freedesktop.org/pipewire/pipewire/-/issues/4793
Fixes: 042bb9603c ("Bluetooth: L2CAP: Fix L2CAP MTU negotiation")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
OBEX download from iPhone is currently slow due to small packet size
used to transfer data which doesn't follow the MTU negotiated during
L2CAP connection, i.e. 672 bytes instead of 32767:
< ACL Data TX: Handle 11 flags 0x00 dlen 12
L2CAP: Connection Request (0x02) ident 18 len 4
PSM: 4103 (0x1007)
Source CID: 72
> ACL Data RX: Handle 11 flags 0x02 dlen 16
L2CAP: Connection Response (0x03) ident 18 len 8
Destination CID: 14608
Source CID: 72
Result: Connection successful (0x0000)
Status: No further information available (0x0000)
< ACL Data TX: Handle 11 flags 0x00 dlen 27
L2CAP: Configure Request (0x04) ident 20 len 19
Destination CID: 14608
Flags: 0x0000
Option: Maximum Transmission Unit (0x01) [mandatory]
MTU: 32767
Option: Retransmission and Flow Control (0x04) [mandatory]
Mode: Enhanced Retransmission (0x03)
TX window size: 63
Max transmit: 3
Retransmission timeout: 2000
Monitor timeout: 12000
Maximum PDU size: 1009
> ACL Data RX: Handle 11 flags 0x02 dlen 26
L2CAP: Configure Request (0x04) ident 72 len 18
Destination CID: 72
Flags: 0x0000
Option: Retransmission and Flow Control (0x04) [mandatory]
Mode: Enhanced Retransmission (0x03)
TX window size: 32
Max transmit: 255
Retransmission timeout: 0
Monitor timeout: 0
Maximum PDU size: 65527
Option: Frame Check Sequence (0x05) [mandatory]
FCS: 16-bit FCS (0x01)
< ACL Data TX: Handle 11 flags 0x00 dlen 29
L2CAP: Configure Response (0x05) ident 72 len 21
Source CID: 14608
Flags: 0x0000
Result: Success (0x0000)
Option: Maximum Transmission Unit (0x01) [mandatory]
MTU: 672
Option: Retransmission and Flow Control (0x04) [mandatory]
Mode: Enhanced Retransmission (0x03)
TX window size: 32
Max transmit: 255
Retransmission timeout: 2000
Monitor timeout: 12000
Maximum PDU size: 1009
> ACL Data RX: Handle 11 flags 0x02 dlen 32
L2CAP: Configure Response (0x05) ident 20 len 24
Source CID: 72
Flags: 0x0000
Result: Success (0x0000)
Option: Maximum Transmission Unit (0x01) [mandatory]
MTU: 32767
Option: Retransmission and Flow Control (0x04) [mandatory]
Mode: Enhanced Retransmission (0x03)
TX window size: 63
Max transmit: 3
Retransmission timeout: 2000
Monitor timeout: 12000
Maximum PDU size: 1009
Option: Frame Check Sequence (0x05) [mandatory]
FCS: 16-bit FCS (0x01)
...
> ACL Data RX: Handle 11 flags 0x02 dlen 680
Channel: 72 len 676 ctrl 0x0202 [PSM 4103 mode Enhanced Retransmission (0x03)] {chan 8}
I-frame: Unsegmented TxSeq 1 ReqSeq 2
< ACL Data TX: Handle 11 flags 0x00 dlen 13
Channel: 14608 len 9 ctrl 0x0204 [PSM 4103 mode Enhanced Retransmission (0x03)] {chan 8}
I-frame: Unsegmented TxSeq 2 ReqSeq 2
> ACL Data RX: Handle 11 flags 0x02 dlen 680
Channel: 72 len 676 ctrl 0x0304 [PSM 4103 mode Enhanced Retransmission (0x03)] {chan 8}
I-frame: Unsegmented TxSeq 2 ReqSeq 3
The MTUs are negotiated for each direction. In this traces 32767 for
iPhone->localhost and no MTU for localhost->iPhone, which based on
'4.4 L2CAP_CONFIGURATION_REQ' (Core specification v5.4, Vol. 3, Part
A):
The only parameters that should be included in the
L2CAP_CONFIGURATION_REQ packet are those that require different
values than the default or previously agreed values.
...
Any missing configuration parameters are assumed to have their
most recently explicitly or implicitly accepted values.
and '5.1 Maximum transmission unit (MTU)':
If the remote device sends a positive L2CAP_CONFIGURATION_RSP
packet it should include the actual MTU to be used on this channel
for traffic flowing into the local device.
...
The default value is 672 octets.
is set by BlueZ to 672 bytes.
It seems that the iPhone used the lowest negotiated value to transfer
data to the localhost instead of the negotiated one for the incoming
direction.
This could be fixed by using the MTU negotiated for the other
direction, if exists, in the L2CAP_CONFIGURATION_RSP.
This allows to use segmented packets as in the following traces:
< ACL Data TX: Handle 11 flags 0x00 dlen 12
L2CAP: Connection Request (0x02) ident 22 len 4
PSM: 4103 (0x1007)
Source CID: 72
< ACL Data TX: Handle 11 flags 0x00 dlen 27
L2CAP: Configure Request (0x04) ident 24 len 19
Destination CID: 2832
Flags: 0x0000
Option: Maximum Transmission Unit (0x01) [mandatory]
MTU: 32767
Option: Retransmission and Flow Control (0x04) [mandatory]
Mode: Enhanced Retransmission (0x03)
TX window size: 63
Max transmit: 3
Retransmission timeout: 2000
Monitor timeout: 12000
Maximum PDU size: 1009
> ACL Data RX: Handle 11 flags 0x02 dlen 26
L2CAP: Configure Request (0x04) ident 15 len 18
Destination CID: 72
Flags: 0x0000
Option: Retransmission and Flow Control (0x04) [mandatory]
Mode: Enhanced Retransmission (0x03)
TX window size: 32
Max transmit: 255
Retransmission timeout: 0
Monitor timeout: 0
Maximum PDU size: 65527
Option: Frame Check Sequence (0x05) [mandatory]
FCS: 16-bit FCS (0x01)
< ACL Data TX: Handle 11 flags 0x00 dlen 29
L2CAP: Configure Response (0x05) ident 15 len 21
Source CID: 2832
Flags: 0x0000
Result: Success (0x0000)
Option: Maximum Transmission Unit (0x01) [mandatory]
MTU: 32767
Option: Retransmission and Flow Control (0x04) [mandatory]
Mode: Enhanced Retransmission (0x03)
TX window size: 32
Max transmit: 255
Retransmission timeout: 2000
Monitor timeout: 12000
Maximum PDU size: 1009
> ACL Data RX: Handle 11 flags 0x02 dlen 32
L2CAP: Configure Response (0x05) ident 24 len 24
Source CID: 72
Flags: 0x0000
Result: Success (0x0000)
Option: Maximum Transmission Unit (0x01) [mandatory]
MTU: 32767
Option: Retransmission and Flow Control (0x04) [mandatory]
Mode: Enhanced Retransmission (0x03)
TX window size: 63
Max transmit: 3
Retransmission timeout: 2000
Monitor timeout: 12000
Maximum PDU size: 1009
Option: Frame Check Sequence (0x05) [mandatory]
FCS: 16-bit FCS (0x01)
...
> ACL Data RX: Handle 11 flags 0x02 dlen 1009
Channel: 72 len 1005 ctrl 0x4202 [PSM 4103 mode Enhanced Retransmission (0x03)] {chan 8}
I-frame: Start (len 21884) TxSeq 1 ReqSeq 2
> ACL Data RX: Handle 11 flags 0x02 dlen 1009
Channel: 72 len 1005 ctrl 0xc204 [PSM 4103 mode Enhanced Retransmission (0x03)] {chan 8}
I-frame: Continuation TxSeq 2 ReqSeq 2
This has been tested with kernel 5.4 and BlueZ 5.77.
Cc: stable@vger.kernel.org
Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Depending on the security set the response to L2CAP_LE_CONN_REQ shall be
just L2CAP_CR_LE_ENCRYPTION if only encryption when BT_SECURITY_MEDIUM
is selected since that means security mode 2 which doesn't require
authentication which is something that is covered in the qualification
test L2CAP/LE/CFC/BV-25-C.
Link: https://github.com/bluez/bluez/issues/1270
Fixes: 27e2d4c8d2 ("Bluetooth: Add basic LE L2CAP connect request receiving support")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
l2cap_check_enc_key_size shall check the security level of the
l2cap_chan rather than the hci_conn since for incoming connection
request that may be different as hci_conn may already been
encrypted using a different security level.
Fixes: 522e9ed157 ("Bluetooth: l2cap: Check encryption key size on incoming connection")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Copy timestamp too when allocating new skb for received fragment.
Fixes missing RX timestamps with fragmentation.
Fixes: 4d7ea8ee90 ("Bluetooth: L2CAP: Fix handling fragmented length")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This is required for passing PTS test cases:
- L2CAP/COS/CED/BI-14-C
Multiple Signaling Command in one PDU, Data Truncated, BR/EDR,
Connection Request
- L2CAP/COS/CED/BI-15-C
Multiple Signaling Command in one PDU, Data Truncated, BR/EDR,
Disconnection Request
The test procedure defined in L2CAP.TS.p39 for both tests is:
1. The Lower Tester sends a C-frame to the IUT with PDU Length set
to 8 and Channel ID set to the correct signaling channel for the
logical link. The Information payload contains one L2CAP_ECHO_REQ
packet with Data Length set to 0 with 0 octets of echo data and
one command packet and Data Length set as specified in Table 4.6
and the correct command data.
2. The IUT sends an L2CAP_ECHO_RSP PDU to the Lower Tester.
3. Perform alternative 3A, 3B, 3C, or 3D depending on the IUT’s
response.
Alternative 3A (IUT terminates the link):
3A.1 The IUT terminates the link.
3A.2 The test ends with a Pass verdict.
Alternative 3B (IUT discards the frame):
3B.1 The IUT does not send a reply to the Lower Tester.
Alternative 3C (IUT rejects PDU):
3C.1 The IUT sends an L2CAP_COMMAND_REJECT_RSP PDU to the
Lower Tester.
Alternative 3D (Any other IUT response):
3D.1 The Upper Tester issues a warning and the test ends.
4. The Lower Tester sends a C-frame to the IUT with PDU Length set
to 4 and Channel ID set to the correct signaling channel for the
logical link. The Information payload contains Data Length set to
0 with an L2CAP_ECHO_REQ packet with 0 octets of echo data.
5. The IUT sends an L2CAP_ECHO_RSP PDU to the Lower Tester.
With expected outcome:
In Steps 2 and 5, the IUT responds with an L2CAP_ECHO_RSP.
In Step 3A.1, the IUT terminates the link.
In Step 3B.1, the IUT does not send a reply to the Lower Tester.
In Step 3C.1, the IUT rejects the PDU.
In Step 3D.1, the IUT sends any valid response.
Currently PTS fails with the following logs:
Failed to receive ECHO RESPONSE.
And HCI logs:
> ACL Data RX: Handle 11 flags 0x02 dlen 20
L2CAP: Information Response (0x0b) ident 2 len 12
Type: Fixed channels supported (0x0003)
Result: Success (0x0000)
Channels: 0x000000000000002e
L2CAP Signaling (BR/EDR)
Connectionless reception
AMP Manager Protocol
L2CAP Signaling (LE)
> ACL Data RX: Handle 11 flags 0x02 dlen 13
frame too long
08 01 00 00 08 02 01 00 aa .........
Cc: stable@vger.kernel.org
Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Support TX timestamping in L2CAP sockets.
Support MSG_ERRQUEUE recvmsg.
For other than SOCK_STREAM L2CAP sockets, if a packet from sendmsg() is
fragmented, only the first ACL fragment is timestamped.
For SOCK_STREAM L2CAP sockets, use the bytestream convention and
timestamp the last fragment and count bytes in tskey.
Timestamps are not generated in the Enhanced Retransmission mode, as
meaning of COMPLETION stamp is unclear if L2CAP layer retransmits.
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Commit b35108a51c ("jiffies: Define secs_to_jiffies()") introduced
secs_to_jiffies(). As the value here is a multiple of 1000, use
secs_to_jiffies() instead of msecs_to_jiffies() for readability.
Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This reverts commit 4d94f05558 which has
problems (see [1]) and is no longer needed since 581dd2dc16
("Bluetooth: hci_event: Fix using rcu_read_(un)lock while iterating")
has reworked the code where the original bug has been found.
[1] Link: https://lore.kernel.org/linux-bluetooth/877c55ci1r.wl-tiwai@suse.de/T/#t
Fixes: 4d94f05558 ("Bluetooth: hci_core: Fix sleeping function called from invalid context")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
L2CAP_ECRED_CONN_RSP needs to respond DCID in the same order received as
SCID but the order is reversed due to use of list_add which actually
prepend channels to the list so the response is reversed:
> ACL Data RX: Handle 16 flags 0x02 dlen 26
LE L2CAP: Enhanced Credit Connection Request (0x17) ident 2 len 18
PSM: 39 (0x0027)
MTU: 256
MPS: 251
Credits: 65535
Source CID: 116
Source CID: 117
Source CID: 118
Source CID: 119
Source CID: 120
< ACL Data TX: Handle 16 flags 0x00 dlen 26
LE L2CAP: Enhanced Credit Connection Response (0x18) ident 2 len 18
MTU: 517
MPS: 247
Credits: 3
Result: Connection successful (0x0000)
Destination CID: 68
Destination CID: 67
Destination CID: 66
Destination CID: 65
Destination CID: 64
Also make sure the response don't include channels that are not on
BT_CONNECT2 since the chan->ident can be set to the same value as in the
following trace:
< ACL Data TX: Handle 16 flags 0x00 dlen 12
LE L2CAP: LE Flow Control Credit (0x16) ident 6 len 4
Source CID: 64
Credits: 1
...
> ACL Data RX: Handle 16 flags 0x02 dlen 18
LE L2CAP: Enhanced Credit Connection Request (0x17) ident 6 len 10
PSM: 39 (0x0027)
MTU: 517
MPS: 251
Credits: 255
Source CID: 70
< ACL Data TX: Handle 16 flags 0x00 dlen 20
LE L2CAP: Enhanced Credit Connection Response (0x18) ident 6 len 12
MTU: 517
MPS: 247
Credits: 3
Result: Connection successful (0x0000)
Destination CID: 64
Destination CID: 68
Closes: https://github.com/bluez/bluez/issues/1094
Fixes: 9aa9d9473f ("Bluetooth: L2CAP: Fix responding with wrong PDU type")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This fixes the following deadlock introduced by 39a92a55be13
("bluetooth/l2cap: sync sock recv cb and release")
============================================
WARNING: possible recursive locking detected
6.10.0-rc3-g4029dba6b6f1 #6823 Not tainted
--------------------------------------------
kworker/u5:0/35 is trying to acquire lock:
ffff888002ec2510 (&chan->lock#2/1){+.+.}-{3:3}, at:
l2cap_sock_recv_cb+0x44/0x1e0
but task is already holding lock:
ffff888002ec2510 (&chan->lock#2/1){+.+.}-{3:3}, at:
l2cap_get_chan_by_scid+0xaf/0xd0
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&chan->lock#2/1);
lock(&chan->lock#2/1);
*** DEADLOCK ***
May be due to missing lock nesting notation
3 locks held by kworker/u5:0/35:
#0: ffff888002b8a940 ((wq_completion)hci0#2){+.+.}-{0:0}, at:
process_one_work+0x750/0x930
#1: ffff888002c67dd0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0},
at: process_one_work+0x44e/0x930
#2: ffff888002ec2510 (&chan->lock#2/1){+.+.}-{3:3}, at:
l2cap_get_chan_by_scid+0xaf/0xd0
To fix the original problem this introduces l2cap_chan_lock at
l2cap_conless_channel to ensure that l2cap_sock_recv_cb is called with
chan->lock held.
Fixes: 89e856e124 ("bluetooth/l2cap: sync sock recv cb and release")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
The amp_id argument of l2cap_connect() was removed in
commit 84a4bb6548 ("Bluetooth: HCI: Remove HCI_AMP support")
It was always called with amp_id == 0, i.e. AMP_ID_BREDR == 0x00 (ie.
non-AMP controller). In the above commit, the code path for amp_id != 0
was preserved, although it should have used the amp_id == 0 one.
Restore the previous behavior of the non-AMP code path, to fix problems
with L2CAP connections.
Fixes: 84a4bb6548 ("Bluetooth: HCI: Remove HCI_AMP support")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This removes the bogus check for max > hcon->le_conn_max_interval since
the later is just the initial maximum conn interval not the maximum the
stack could support which is really 3200=4000ms.
In order to pass GAP/CONN/CPUP/BV-05-C one shall probably enter values
of the following fields in IXIT that would cause hci_check_conn_params
to fail:
TSPX_conn_update_int_min
TSPX_conn_update_int_max
TSPX_conn_update_peripheral_latency
TSPX_conn_update_supervision_timeout
Link: https://github.com/bluez/bluez/issues/847
Fixes: e4b019515f ("Bluetooth: Enforce validation on max value of connection interval")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Since BT_HS has been remove HCI_AMP controllers no longer has any use so
remove it along with the capability of creating AMP controllers.
Since we no longer need to differentiate between AMP and Primary
controllers, as only HCI_PRIMARY is left, this also remove
hdev->dev_type altogether.
Fixes: e7b02296fb ("Bluetooth: Remove BT_HS")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
