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: 89e856e124f9 ("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 84a4bb6548a2 ("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: 84a4bb6548a2 ("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: e4b019515f95 ("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: e7b02296fb40 ("Bluetooth: Remove BT_HS")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Previously LE flow credits were returned to the
sender even if the socket's receive buffer was
full. This meant that no back-pressure
was applied to the sender, thus it continued to
send data, resulting in data loss without any
error being reported. Furthermore, the amount
of credits was essentially fixed to a small
amount, leading to reduced performance.
This is fixed by computing the number of returned
LE flow credits based on the estimated available
space in the receive buffer of an L2CAP socket.
Consequently, if the receive buffer is full, no
credits are returned until the buffer is read and
thus cleared by user-space.
Since the computation of available receive buffer
space can only be performed approximately (due to
sk_buff overhead) and the receive buffer size may
be changed by user-space after flow credits have
been sent, superfluous received data is temporary
stored within l2cap_pinfo. This is necessary
because Bluetooth LE provides no retransmission
mechanism once the data has been acked by the
physical layer.
If receive buffer space estimation is not possible
at the moment, we fall back to providing credits
for one full packet as before. This is currently
the case during connection setup, when MPS is not
yet available.
Fixes: b1c325c23d75 ("Bluetooth: Implement returning of LE L2CAP credits")
Signed-off-by: Sebastian Urban <surban@surban.net>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally.
There are currently a couple of objects (`req` and `rsp`), in a couple
of structures, that contain flexible structures (`struct l2cap_ecred_conn_req`
and `struct l2cap_ecred_conn_rsp`), for example:
struct l2cap_ecred_rsp_data {
struct {
struct l2cap_ecred_conn_rsp rsp;
__le16 scid[L2CAP_ECRED_MAX_CID];
} __packed pdu;
int count;
};
in the struct above, `struct l2cap_ecred_conn_rsp` is a flexible
structure:
struct l2cap_ecred_conn_rsp {
__le16 mtu;
__le16 mps;
__le16 credits;
__le16 result;
__le16 dcid[];
};
So, in order to avoid ending up with a flexible-array member in the
middle of another structure, we use the `struct_group_tagged()` (and
`__struct_group()` when the flexible structure is `__packed`) helper
to separate the flexible array from the rest of the members in the
flexible structure:
struct l2cap_ecred_conn_rsp {
struct_group_tagged(l2cap_ecred_conn_rsp_hdr, hdr,
... the rest of members
);
__le16 dcid[];
};
With the change described above, we now declare objects of the type of
the tagged struct, in this example `struct l2cap_ecred_conn_rsp_hdr`,
without embedding flexible arrays in the middle of other structures:
struct l2cap_ecred_rsp_data {
struct {
struct l2cap_ecred_conn_rsp_hdr rsp;
__le16 scid[L2CAP_ECRED_MAX_CID];
} __packed pdu;
int count;
};
Also, when the flexible-array member needs to be accessed, we use
`container_of()` to retrieve a pointer to the flexible structure.
We also use the `DEFINE_RAW_FLEX()` helper for a couple of on-stack
definitions of a flexible structure where the size of the flexible-array
member is known at compile-time.
So, with these changes, fix the following warnings:
net/bluetooth/l2cap_core.c:1260:45: warning: structure containing a
flexible array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
net/bluetooth/l2cap_core.c:3740:45: warning: structure containing a
flexible array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
net/bluetooth/l2cap_core.c:4999:45: warning: structure containing a
flexible array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
net/bluetooth/l2cap_core.c:7116:47: warning: structure containing a
flexible array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
Link: https://github.com/KSPP/linux/issues/202
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Extend a critical section to prevent chan from early freeing.
Also make the l2cap_connect() return type void. Nothing is using the
returned value but it is ugly to return a potentially freed pointer.
Making it void will help with backports because earlier kernels did use
the return value. Now the compile will break for kernels where this
patch is not a complete fix.
Call stack summary:
[use]
l2cap_bredr_sig_cmd
l2cap_connect
┌ mutex_lock(&conn->chan_lock);
│ chan = pchan->ops->new_connection(pchan); <- alloc chan
│ __l2cap_chan_add(conn, chan);
│ l2cap_chan_hold(chan);
│ list_add(&chan->list, &conn->chan_l); ... (1)
└ mutex_unlock(&conn->chan_lock);
chan->conf_state ... (4) <- use after free
[free]
l2cap_conn_del
┌ mutex_lock(&conn->chan_lock);
│ foreach chan in conn->chan_l: ... (2)
│ l2cap_chan_put(chan);
│ l2cap_chan_destroy
│ kfree(chan) ... (3) <- chan freed
└ mutex_unlock(&conn->chan_lock);
==================================================================
BUG: KASAN: slab-use-after-free in instrument_atomic_read
include/linux/instrumented.h:68 [inline]
BUG: KASAN: slab-use-after-free in _test_bit
include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
BUG: KASAN: slab-use-after-free in l2cap_connect+0xa67/0x11a0
net/bluetooth/l2cap_core.c:4260
Read of size 8 at addr ffff88810bf040a0 by task kworker/u3:1/311
Fixes: 73ffa904b782 ("Bluetooth: Move conf_{req,rsp} stuff to struct l2cap_chan")
Signed-off-by: Sungwoo Kim <iam@sung-woo.kim>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
The extended advertising reports do report the PHYs so this store then
in hci_conn so it can be later used in hci_le_ext_create_conn_sync to
narrow the PHYs to be scanned since the controller will also perform a
scan having a smaller set of PHYs shall reduce the time it takes to
find and connect peers.
Fixes: 288c90224eec ("Bluetooth: Enable all supported LE PHY by default")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
The bit is set and tested inside mgmt_device_connected(), therefore we
must not set it just outside the function.
Fixes: eeda1bf97bb5 ("Bluetooth: hci_event: Fix not indicating new connection for BIG Sync")
Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Manish Mandlik <mmandlik@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This aligns the use socket sk_timeo as conn_timeout when initiating a
connection and then use it when scheduling the resulting HCI command,
that way the command is actually aborted synchronously thus not
blocking commands generated by hci_abort_conn_sync to inform the
controller the connection is to be aborted.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Right now Linux BT stack cannot pass test case "GAP/CONN/CPUP/BV-05-C
'Connection Parameter Update Procedure Invalid Parameters Central
Responder'" in Bluetooth Test Suite revision GAP.TS.p44. [0]
That was revoled by commit c49a8682fc5d ("Bluetooth: validate BLE
connection interval updates"), but later got reverted due to devices
like keyboards and mice may require low connection interval.
So only validate the max value connection interval to pass the Test
Suite, and let devices to request low connection interval if needed.
[0] https://www.bluetooth.org/docman/handlers/DownloadDoc.ashx?doc_id=229869
Fixes: 68d19d7d9957 ("Revert "Bluetooth: validate BLE connection interval updates"")
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
In case of an incomplete command or a command with a null identifier 2
reject packets will be sent, one with the identifier and one with 0.
Consuming the data of the command will prevent it.
This allows to send a reject packet for each corrupted command in a
multi-command packet.
Signed-off-by: Frédéric Danis <frederic.danis@collabora.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
L2CAP/COS/CED/BI-02-C PTS test send a malformed L2CAP signaling packet
with 2 commands in it (a connection request and an unknown command) and
expect to get a connection response packet and a command reject packet.
The second is currently not sent.
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>
Fix potential use-after-free in l2cap_le_command_rej.
Signed-off-by: Zhengping Jiang <jiangzp@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When receiving a connect response we should make sure that the DCID is
within the valid range and that we don't already have another channel
allocated for the same DCID.
Missing checks may violate the specification (BLUETOOTH CORE SPECIFICATION
Version 5.4 | Vol 3, Part A, Page 1046).
Fixes: 40624183c202 ("Bluetooth: L2CAP: Add missing checks for invalid LE DCID")
Signed-off-by: Sungwoo Kim <iam@sung-woo.kim>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
L2CAP assumes that the locks conn->chan_lock and chan->lock are
acquired in the order conn->chan_lock, chan->lock to avoid
potential deadlock.
For example, l2sock_shutdown acquires these locks in the order:
mutex_lock(&conn->chan_lock)
l2cap_chan_lock(chan)
However, l2cap_disconnect_req acquires chan->lock in
l2cap_get_chan_by_scid first and then acquires conn->chan_lock
before calling l2cap_chan_del. This means that these locks are
acquired in unexpected order, which leads to potential deadlock:
l2cap_chan_lock(c)
mutex_lock(&conn->chan_lock)
This patch releases chan->lock before acquiring the conn_chan_lock
to avoid the potential deadlock.
Fixes: a2a9339e1c9d ("Bluetooth: L2CAP: Fix use-after-free in l2cap_disconnect_{req,rsp}")
Signed-off-by: Ying Hsu <yinghsu@chromium.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This delays the identity address updates to give time for userspace to
process the new address otherwise there is a risk that userspace
creates a duplicated device if the MGMT event is delayed for some
reason.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Similar to commit d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free
caused by l2cap_chan_put"), just use l2cap_chan_hold_unless_zero to
prevent referencing a channel that is about to be destroyed.
Cc: stable@kernel.org
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Min Li <lm0963hack@gmail.com>
L2CAP_ECRED_CONN_REQ shall be responded with L2CAP_ECRED_CONN_RSP not
L2CAP_LE_CONN_RSP:
L2CAP LE EATT Server - Reject - run
Listening for connections
New client connection with handle 0x002a
Sending L2CAP Request from client
Client received response code 0x15
Unexpected L2CAP response code (expected 0x18)
L2CAP LE EATT Server - Reject - test failed
> ACL Data RX: Handle 42 flags 0x02 dlen 26
LE L2CAP: Enhanced Credit Connection Request (0x17) ident 1 len 18
PSM: 39 (0x0027)
MTU: 64
MPS: 64
Credits: 5
Source CID: 65
Source CID: 66
Source CID: 67
Source CID: 68
Source CID: 69
< ACL Data TX: Handle 42 flags 0x00 dlen 16
LE L2CAP: LE Connection Response (0x15) ident 1 len 8
invalid size
00 00 00 00 00 00 06 00
L2CAP LE EATT Server - Reject - run
Listening for connections
New client connection with handle 0x002a
Sending L2CAP Request from client
Client received response code 0x18
L2CAP LE EATT Server - Reject - test passed
Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This fixes all instances of which requires to allocate a buffer calling
alloc_skb which may release the chan lock and reacquire later which
makes it possible that the chan is disconnected in the meantime.
Fixes: a6a5568c03c4 ("Bluetooth: Lock the L2CAP channel when sending")
Reported-by: Alexander Coffin <alex.coffin@matician.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This adds CONFIG_BT_LE_L2CAP_ECRED which can be used to enable L2CAP
Enhanced Credit Flow Control Mode by default, previously it was only
possible to set it via module parameter (e.g. bluetooth.enable_ecred=1).
Since L2CAP ECRED mode is required by the likes of EATT which is
recommended for LE Audio this enables it by default.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-By: Tedd Ho-Jeong An <tedd.an@intel.com>
On l2cap_parse_conf_req the variable efs is only initialized if
remote_efs has been set.
CVE: CVE-2022-42895
CC: stable@vger.kernel.org
Reported-by: Tamás Koczka <poprdi@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Reviewed-by: Tedd Ho-Jeong An <tedd.an@intel.com>
l2cap_global_chan_by_psm shall not return fixed channels as they are not
meant to be connected by (S)PSM.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Reviewed-by: Tedd Ho-Jeong An <tedd.an@intel.com>
The Bluetooth spec states that the valid range for SPSM is from
0x0001-0x00ff so it is invalid to accept values outside of this range:
BLUETOOTH CORE SPECIFICATION Version 5.3 | Vol 3, Part A
page 1059:
Table 4.15: L2CAP_LE_CREDIT_BASED_CONNECTION_REQ SPSM ranges
CVE: CVE-2022-42896
CC: stable@vger.kernel.org
Reported-by: Tamás Koczka <poprdi@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Reviewed-by: Tedd Ho-Jeong An <tedd.an@intel.com>
Syzkaller reports a memory leak as follows:
====================================
BUG: memory leak
unreferenced object 0xffff88810d81ac00 (size 240):
[...]
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff838733d9>] __alloc_skb+0x1f9/0x270 net/core/skbuff.c:418
[<ffffffff833f742f>] alloc_skb include/linux/skbuff.h:1257 [inline]
[<ffffffff833f742f>] bt_skb_alloc include/net/bluetooth/bluetooth.h:469 [inline]
[<ffffffff833f742f>] vhci_get_user drivers/bluetooth/hci_vhci.c:391 [inline]
[<ffffffff833f742f>] vhci_write+0x5f/0x230 drivers/bluetooth/hci_vhci.c:511
[<ffffffff815e398d>] call_write_iter include/linux/fs.h:2192 [inline]
[<ffffffff815e398d>] new_sync_write fs/read_write.c:491 [inline]
[<ffffffff815e398d>] vfs_write+0x42d/0x540 fs/read_write.c:578
[<ffffffff815e3cdd>] ksys_write+0x9d/0x160 fs/read_write.c:631
[<ffffffff845e0645>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<ffffffff845e0645>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
[<ffffffff84600087>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
====================================
HCI core will uses hci_rx_work() to process frame, which is queued to
the hdev->rx_q tail in hci_recv_frame() by HCI driver.
Yet the problem is that, HCI core may not free the skb after handling
ACL data packets. To be more specific, when start fragment does not
contain the L2CAP length, HCI core just copies skb into conn->rx_skb and
finishes frame process in l2cap_recv_acldata(), without freeing the skb,
which triggers the above memory leak.
This patch solves it by releasing the relative skb, after processing
the above case in l2cap_recv_acldata().
Fixes: 4d7ea8ee90e4 ("Bluetooth: L2CAP: Fix handling fragmented length")
Link: https://lore.kernel.org/all/0000000000000d0b1905e6aaef64@google.com/
Reported-and-tested-by: syzbot+8f819e36e01022991cfa@syzkaller.appspotmail.com
Signed-off-by: Hawkins Jiawei <yin31149@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
When l2cap_recv_frame() is invoked to receive data, and the cid is
L2CAP_CID_A2MP, if the channel does not exist, it will create a channel.
However, after a channel is created, the hold operation of the channel
is not performed. In this case, the value of channel reference counting
is 1. As a result, after hci_error_reset() is triggered, l2cap_conn_del()
invokes the close hook function of A2MP to release the channel. Then
l2cap_chan_unlock(chan) will trigger UAF issue.
The process is as follows:
Receive data:
l2cap_data_channel()
a2mp_channel_create() --->channel ref is 2
l2cap_chan_put() --->channel ref is 1
Triger event:
hci_error_reset()
hci_dev_do_close()
...
l2cap_disconn_cfm()
l2cap_conn_del()
l2cap_chan_hold() --->channel ref is 2
l2cap_chan_del() --->channel ref is 1
a2mp_chan_close_cb() --->channel ref is 0, release channel
l2cap_chan_unlock() --->UAF of channel
The detailed Call Trace is as follows:
BUG: KASAN: use-after-free in __mutex_unlock_slowpath+0xa6/0x5e0
Read of size 8 at addr ffff8880160664b8 by task kworker/u11:1/7593
Workqueue: hci0 hci_error_reset
Call Trace:
<TASK>
dump_stack_lvl+0xcd/0x134
print_report.cold+0x2ba/0x719
kasan_report+0xb1/0x1e0
kasan_check_range+0x140/0x190
__mutex_unlock_slowpath+0xa6/0x5e0
l2cap_conn_del+0x404/0x7b0
l2cap_disconn_cfm+0x8c/0xc0
hci_conn_hash_flush+0x11f/0x260
hci_dev_close_sync+0x5f5/0x11f0
hci_dev_do_close+0x2d/0x70
hci_error_reset+0x9e/0x140
process_one_work+0x98a/0x1620
worker_thread+0x665/0x1080
kthread+0x2e4/0x3a0
ret_from_fork+0x1f/0x30
</TASK>
Allocated by task 7593:
kasan_save_stack+0x1e/0x40
__kasan_kmalloc+0xa9/0xd0
l2cap_chan_create+0x40/0x930
amp_mgr_create+0x96/0x990
a2mp_channel_create+0x7d/0x150
l2cap_recv_frame+0x51b8/0x9a70
l2cap_recv_acldata+0xaa3/0xc00
hci_rx_work+0x702/0x1220
process_one_work+0x98a/0x1620
worker_thread+0x665/0x1080
kthread+0x2e4/0x3a0
ret_from_fork+0x1f/0x30
Freed by task 7593:
kasan_save_stack+0x1e/0x40
kasan_set_track+0x21/0x30
kasan_set_free_info+0x20/0x30
____kasan_slab_free+0x167/0x1c0
slab_free_freelist_hook+0x89/0x1c0
kfree+0xe2/0x580
l2cap_chan_put+0x22a/0x2d0
l2cap_conn_del+0x3fc/0x7b0
l2cap_disconn_cfm+0x8c/0xc0
hci_conn_hash_flush+0x11f/0x260
hci_dev_close_sync+0x5f5/0x11f0
hci_dev_do_close+0x2d/0x70
hci_error_reset+0x9e/0x140
process_one_work+0x98a/0x1620
worker_thread+0x665/0x1080
kthread+0x2e4/0x3a0
ret_from_fork+0x1f/0x30
Last potentially related work creation:
kasan_save_stack+0x1e/0x40
__kasan_record_aux_stack+0xbe/0xd0
call_rcu+0x99/0x740
netlink_release+0xe6a/0x1cf0
__sock_release+0xcd/0x280
sock_close+0x18/0x20
__fput+0x27c/0xa90
task_work_run+0xdd/0x1a0
exit_to_user_mode_prepare+0x23c/0x250
syscall_exit_to_user_mode+0x19/0x50
do_syscall_64+0x42/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Second to last potentially related work creation:
kasan_save_stack+0x1e/0x40
__kasan_record_aux_stack+0xbe/0xd0
call_rcu+0x99/0x740
netlink_release+0xe6a/0x1cf0
__sock_release+0xcd/0x280
sock_close+0x18/0x20
__fput+0x27c/0xa90
task_work_run+0xdd/0x1a0
exit_to_user_mode_prepare+0x23c/0x250
syscall_exit_to_user_mode+0x19/0x50
do_syscall_64+0x42/0x80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put")
Signed-off-by: Zhengchao Shao <shaozhengchao@huawei.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Fix the race condition between the following two flows that run in
parallel:
1. l2cap_reassemble_sdu -> chan->ops->recv (l2cap_sock_recv_cb) ->
__sock_queue_rcv_skb.
2. bt_sock_recvmsg -> skb_recv_datagram, skb_free_datagram.
An SKB can be queued by the first flow and immediately dequeued and
freed by the second flow, therefore the callers of l2cap_reassemble_sdu
can't use the SKB after that function returns. However, some places
continue accessing struct l2cap_ctrl that resides in the SKB's CB for a
short time after l2cap_reassemble_sdu returns, leading to a
use-after-free condition (the stack trace is below, line numbers for
kernel 5.19.8).
Fix it by keeping a local copy of struct l2cap_ctrl.
BUG: KASAN: use-after-free in l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth
Read of size 1 at addr ffff88812025f2f0 by task kworker/u17:3/43169
Workqueue: hci0 hci_rx_work [bluetooth]
Call Trace:
<TASK>
dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4))
print_report.cold (mm/kasan/report.c:314 mm/kasan/report.c:429)
? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth
kasan_report (mm/kasan/report.c:162 mm/kasan/report.c:493)
? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth
l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth
l2cap_rx (net/bluetooth/l2cap_core.c:7236 net/bluetooth/l2cap_core.c:7271) bluetooth
ret_from_fork (arch/x86/entry/entry_64.S:306)
</TASK>
Allocated by task 43169:
kasan_save_stack (mm/kasan/common.c:39)
__kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469)
kmem_cache_alloc_node (mm/slab.h:750 mm/slub.c:3243 mm/slub.c:3293)
__alloc_skb (net/core/skbuff.c:414)
l2cap_recv_frag (./include/net/bluetooth/bluetooth.h:425 net/bluetooth/l2cap_core.c:8329) bluetooth
l2cap_recv_acldata (net/bluetooth/l2cap_core.c:8442) bluetooth
hci_rx_work (net/bluetooth/hci_core.c:3642 net/bluetooth/hci_core.c:3832) bluetooth
process_one_work (kernel/workqueue.c:2289)
worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2437)
kthread (kernel/kthread.c:376)
ret_from_fork (arch/x86/entry/entry_64.S:306)
Freed by task 27920:
kasan_save_stack (mm/kasan/common.c:39)
kasan_set_track (mm/kasan/common.c:45)
kasan_set_free_info (mm/kasan/generic.c:372)
____kasan_slab_free (mm/kasan/common.c:368 mm/kasan/common.c:328)
slab_free_freelist_hook (mm/slub.c:1780)
kmem_cache_free (mm/slub.c:3536 mm/slub.c:3553)
skb_free_datagram (./include/net/sock.h:1578 ./include/net/sock.h:1639 net/core/datagram.c:323)
bt_sock_recvmsg (net/bluetooth/af_bluetooth.c:295) bluetooth
l2cap_sock_recvmsg (net/bluetooth/l2cap_sock.c:1212) bluetooth
sock_read_iter (net/socket.c:1087)
new_sync_read (./include/linux/fs.h:2052 fs/read_write.c:401)
vfs_read (fs/read_write.c:482)
ksys_read (fs/read_write.c:620)
do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)
entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
Link: https://lore.kernel.org/linux-bluetooth/CAKErNvoqga1WcmoR3-0875esY6TVWFQDandbVZncSiuGPBQXLA@mail.gmail.com/T/#u
Fixes: d2a7ac5d5d3a ("Bluetooth: Add the ERTM receive state machine")
Fixes: 4b51dae96731 ("Bluetooth: Add streaming mode receive and incoming packet classifier")
Signed-off-by: Maxim Mikityanskiy <maxtram95@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This uses l2cap_chan_hold_unless_zero() after calling
__l2cap_get_chan_blah() to prevent the following trace:
Bluetooth: l2cap_core.c:static void l2cap_chan_destroy(struct kref
*kref)
Bluetooth: chan 0000000023c4974d
Bluetooth: parent 00000000ae861c08
==================================================================
BUG: KASAN: use-after-free in __mutex_waiter_is_first
kernel/locking/mutex.c:191 [inline]
BUG: KASAN: use-after-free in __mutex_lock_common
kernel/locking/mutex.c:671 [inline]
BUG: KASAN: use-after-free in __mutex_lock+0x278/0x400
kernel/locking/mutex.c:729
Read of size 8 at addr ffff888006a49b08 by task kworker/u3:2/389
Link: https://lore.kernel.org/lkml/20220622082716.478486-1-lee.jones@linaro.org
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sungwoo Kim <iam@sung-woo.kim>
syzbot is reporting cancel_delayed_work() without INIT_DELAYED_WORK() at
l2cap_chan_del() [1], for CONF_NOT_COMPLETE flag (which meant to prevent
l2cap_chan_del() from calling cancel_delayed_work()) is cleared by timer
which fires before l2cap_chan_del() is called by closing file descriptor
created by socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_L2CAP).
l2cap_bredr_sig_cmd(L2CAP_CONF_REQ) and l2cap_bredr_sig_cmd(L2CAP_CONF_RSP)
are calling l2cap_ertm_init(chan), and they call l2cap_chan_ready() (which
clears CONF_NOT_COMPLETE flag) only when l2cap_ertm_init(chan) succeeded.
l2cap_sock_init() does not call l2cap_ertm_init(chan), and it instead sets
CONF_NOT_COMPLETE flag by calling l2cap_chan_set_defaults(). However, when
connect() is requested, "command 0x0409 tx timeout" happens after 2 seconds
from connect() request, and CONF_NOT_COMPLETE flag is cleared after 4
seconds from connect() request, for l2cap_conn_start() from
l2cap_info_timeout() callback scheduled by
schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT);
in l2cap_connect() is calling l2cap_chan_ready().
Fix this problem by initializing delayed works used by L2CAP_MODE_ERTM
mode as soon as l2cap_chan_create() allocates a channel, like I did in
commit be8597239379f0f5 ("Bluetooth: initialize skb_queue_head at
l2cap_chan_create()").
Link: https://syzkaller.appspot.com/bug?extid=83672956c7aa6af698b3 [1]
Reported-by: syzbot <syzbot+83672956c7aa6af698b3@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This attempts to fix the follow errors:
In function 'memcmp',
inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9,
inlined from 'l2cap_global_chan_by_psm' at
net/bluetooth/l2cap_core.c:2003:15:
./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp'
specified bound 6 exceeds source size 0 [-Werror=stringop-overread]
44 | #define __underlying_memcmp __builtin_memcmp
| ^
./include/linux/fortify-string.h:420:16: note: in expansion of macro
'__underlying_memcmp'
420 | return __underlying_memcmp(p, q, size);
| ^~~~~~~~~~~~~~~~~~~
In function 'memcmp',
inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9,
inlined from 'l2cap_global_chan_by_psm' at
net/bluetooth/l2cap_core.c:2004:15:
./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp'
specified bound 6 exceeds source size 0 [-Werror=stringop-overread]
44 | #define __underlying_memcmp __builtin_memcmp
| ^
./include/linux/fortify-string.h:420:16: note: in expansion of macro
'__underlying_memcmp'
420 | return __underlying_memcmp(p, q, size);
| ^~~~~~~~~~~~~~~~~~~
Fixes: 332f1795ca20 ("Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
The patch d0be8347c623: "Bluetooth: L2CAP: Fix use-after-free caused
by l2cap_chan_put" from Jul 21, 2022, leads to the following Smatch
static checker warning:
net/bluetooth/l2cap_core.c:1977 l2cap_global_chan_by_psm()
error: we previously assumed 'c' could be null (see line 1996)
Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
This fixes the following trace which is caused by hci_rx_work starting up
*after* the final channel reference has been put() during sock_close() but
*before* the references to the channel have been destroyed, so instead
the code now rely on kref_get_unless_zero/l2cap_chan_hold_unless_zero to
prevent referencing a channel that is about to be destroyed.
refcount_t: increment on 0; use-after-free.
BUG: KASAN: use-after-free in refcount_dec_and_test+0x20/0xd0
Read of size 4 at addr ffffffc114f5bf18 by task kworker/u17:14/705
CPU: 4 PID: 705 Comm: kworker/u17:14 Tainted: G S W
4.14.234-00003-g1fb6d0bd49a4-dirty #28
Hardware name: Qualcomm Technologies, Inc. SM8150 V2 PM8150
Google Inc. MSM sm8150 Flame DVT (DT)
Workqueue: hci0 hci_rx_work
Call trace:
dump_backtrace+0x0/0x378
show_stack+0x20/0x2c
dump_stack+0x124/0x148
print_address_description+0x80/0x2e8
__kasan_report+0x168/0x188
kasan_report+0x10/0x18
__asan_load4+0x84/0x8c
refcount_dec_and_test+0x20/0xd0
l2cap_chan_put+0x48/0x12c
l2cap_recv_frame+0x4770/0x6550
l2cap_recv_acldata+0x44c/0x7a4
hci_acldata_packet+0x100/0x188
hci_rx_work+0x178/0x23c
process_one_work+0x35c/0x95c
worker_thread+0x4cc/0x960
kthread+0x1a8/0x1c4
ret_from_fork+0x10/0x18
Cc: stable@kernel.org
Reported-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Tested-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Similar to the handling of l2cap_ecred_connect in commit d3715b2333e9
("Bluetooth: use memset avoid memory leaks"), we thought a patch
might be needed here as well.
Use memset to initialize structs to prevent memory leaks
in l2cap_le_connect
Signed-off-by: Xiaohui Zhang <xiaohuizhang@ruc.edu.cn>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
data.pid is set twice with the same value. Remove one of these redundant
calls.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Use memset to initialize structs to prevent memory leaks
in l2cap_ecred_connect
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: Minghao Chi (CGEL ZTE) <chi.minghao@zte.com.cn>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This adds hci_le_create_conn_sync and make hci_le_connect use it instead
of queueing multiple commands which may conflict with the likes of
hci_update_passive_scan which uses hci_cmd_sync_queue.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When connecting to a device using an RPA if the address has been
resolved by the controller (types 0x02 and 0x03) the identity address
shall be used as the actual RPA in the advertisement won't be visible
to the host.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch replaces some non-inclusive terms based on the appropriate
language mapping table compiled by the Bluetooth SIG:
https://specificationrefs.bluetooth.com/language-mapping/Appropriate_Language_Mapping_Table.pdf
Specifically, these terms are replaced:
blacklist -> reject list
whitelist -> accept list
Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
This patch replaces some non-inclusive terms based on the appropriate
language mapping table compiled by the Bluetooth SIG:
https://specificationrefs.bluetooth.com/language-mapping/Appropriate_Language_Mapping_Table.pdf
Specifically, these terms are replaced:
master -> initiator (for smp) or central (everything else)
slave -> responder (for smp) or peripheral (everything else)
The #define preprocessor terms are unchanged for now to not disturb
dependent APIs.
Signed-off-by: Archie Pusaka <apusaka@chromium.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The use of l2cap_chan_del is not safe under a loop using
list_for_each_entry.
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
The use of l2cap_chan_del is not safe under a loop using
list_for_each_entry.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
When an MGMT_EV_DEVICE_CONNECTED event is reported back to the user
space we will set the flags to tell if the established connection is
outbound or not. This is useful for the user space to log better metrics
and error messages.
Reviewed-by: Miao-chen Chou <mcchou@chromium.org>
Reviewed-by: Alain Michaud <alainm@chromium.org>
Signed-off-by: Yu Liu <yudiliu@google.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
