linux-stable.git/net/bluetooth, branch v6.1.185 Linux kernel stable tree Bluetooth: hci_event: fix LE list UAF on reset 2026-08-27T12:29:06+00:00 Chengfeng Ye nicoyip.dev@gmail.com 2026-07-30T08:32:02+00:00 8e68c380290b1dd64a0a512ce66d0264130c46ed commit 33af47e847fe4a28b109673affb5874015d54f5a upstream. hci_cc_reset() clears the LE accept and resolving lists without taking hdev->lock. Other command-complete handlers serialize updates to these lists with that lock, and the debugfs readers hold it while walking them. This permits the reset completion and a debugfs read to interleave as follows: hci_rx_work debugfs reader ----------- -------------- lock hdev->lock fetch current entry list_del(entry) kfree(entry) read entry fields The reader then dereferences a freed list entry and may follow its stale next pointer. KASAN reported: BUG: KASAN: slab-use-after-free in white_list_show+0x15f/0x180 Read of size 1 at addr ffff8881015dab16 by task poc/95 Call Trace: white_list_show+0x15f/0x180 seq_read_iter+0x3ff/0x1190 seq_read+0x267/0x3d0 vfs_read+0x177/0xa20 ksys_read+0xf7/0x1c0 Allocated by task 91: hci_bdaddr_list_add+0x1a6/0x3a0 hci_cc_le_add_to_accept_list+0xab/0x140 hci_cmd_complete_evt+0x26c/0x9a0 hci_event_packet+0x454/0xb20 hci_rx_work+0x293/0x730 Freed by task 90: kfree+0x131/0x3c0 hci_bdaddr_list_clear+0xd8/0x160 hci_cc_reset+0x28a/0x370 hci_cmd_complete_evt+0x26c/0x9a0 hci_event_packet+0x454/0xb20 hci_rx_work+0x293/0x730 Take hdev->lock around both list clears. This matches the existing mutation and traversal locking convention. Fixes: a4d5504d5c39 ("Bluetooth: Clear LE white list when resetting controller") Fixes: cfdb0c2d095a ("Bluetooth: Store Resolv list size") Cc: stable@vger.kernel.org Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 33af47e847fe4a28b109673affb5874015d54f5a upstream.

hci_cc_reset() clears the LE accept and resolving lists without taking
hdev->lock. Other command-complete handlers serialize updates to these
lists with that lock, and the debugfs readers hold it while walking them.

This permits the reset completion and a debugfs read to interleave as
follows:

  hci_rx_work                 debugfs reader
  -----------                 --------------
                              lock hdev->lock
                              fetch current entry
  list_del(entry)
  kfree(entry)
                              read entry fields

The reader then dereferences a freed list entry and may follow its stale
next pointer.

KASAN reported:

  BUG: KASAN: slab-use-after-free in white_list_show+0x15f/0x180
  Read of size 1 at addr ffff8881015dab16 by task poc/95

  Call Trace:
   white_list_show+0x15f/0x180
   seq_read_iter+0x3ff/0x1190
   seq_read+0x267/0x3d0
   vfs_read+0x177/0xa20
   ksys_read+0xf7/0x1c0

  Allocated by task 91:
   hci_bdaddr_list_add+0x1a6/0x3a0
   hci_cc_le_add_to_accept_list+0xab/0x140
   hci_cmd_complete_evt+0x26c/0x9a0
   hci_event_packet+0x454/0xb20
   hci_rx_work+0x293/0x730

  Freed by task 90:
   kfree+0x131/0x3c0
   hci_bdaddr_list_clear+0xd8/0x160
   hci_cc_reset+0x28a/0x370
   hci_cmd_complete_evt+0x26c/0x9a0
   hci_event_packet+0x454/0xb20
   hci_rx_work+0x293/0x730

Take hdev->lock around both list clears. This matches the existing
mutation and traversal locking convention.

Fixes: a4d5504d5c39 ("Bluetooth: Clear LE white list when resetting controller")
Fixes: cfdb0c2d095a ("Bluetooth: Store Resolv list size")
Cc: stable@vger.kernel.org
Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: RFCOMM: take rfcomm_mutex for the deferred setup accept 2026-08-27T12:29:01+00:00 Ali Ahmet Memis ali@iusegentoo.com 2026-08-07T02:03:44+00:00 56f0aa75c7640e46397ef73bea251fcbef9150c0 commit 43a556b2fd43f2df6dded59c2e26560a27874c24 upstream. rfcomm_sock_recvmsg() completes a deferred setup by calling rfcomm_dlc_accept() without holding any RFCOMM lock: if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) { rfcomm_dlc_accept(d); return 0; } and rfcomm_dlc_accept() dereferences the session on its first line: struct sock *sk = d->session->sock->sk; Every other path that touches d->session runs under rfcomm_mutex: rfcomm_dlc_open(), rfcomm_dlc_close(), rfcomm_dlc_exists(), rfcomm_dlc_send_rpn(), and the RFCOMM thread through rfcomm_process_sessions(). rfcomm_connect_ind() is even documented as "called under rfcomm_lock()". This call site is the only one that skips it. The RFCOMM_DEFER_SETUP bit looks like it serialises the accept against teardown, since __rfcomm_dlc_close() returns early when it wins the test_and_clear. But rfcomm_recv_disc() forces the state first: d->state = BT_CLOSED; __rfcomm_dlc_close(d, err); and the early return only covers BT_CONNECT, BT_CONFIG, BT_OPEN and BT_CONNECT2. With the state already BT_CLOSED that switch does not match, the bit is never consulted, and __rfcomm_dlc_close() falls through to rfcomm_dlc_unlink(), which sets d->session = NULL. So a remote DISC on a deferred dlc clears the session while leaving RFCOMM_DEFER_SETUP set. The next recvmsg() then passes the test_and_clear and dereferences a NULL session. No timing window is needed: once the DISC has been processed, the dereference is unconditional. Give rfcomm_dlc_accept() the same shape as rfcomm_dlc_open() and rfcomm_dlc_close(): an exported wrapper that takes rfcomm_mutex and re-checks the session, around a __rfcomm_dlc_accept() that the two in-core callers, which already hold the mutex, keep using. Reproduced on a KASAN + PROVE_LOCKING kernel with a BR/EDR peer emulated over /dev/vhci: the peer brings up an ACL link, opens L2CAP on the RFCOMM PSM, starts a session, opens a dlc on a channel bound with BT_DEFER_SETUP, and sends DISC after the socket is accepted. recv() on the accepted socket then hits: Oops: general protection fault KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:rfcomm_dlc_accept+0x54/0x350 Call Trace: rfcomm_sock_recvmsg+0x1cd/0x230 sock_recvmsg+0x166/0x1c0 __sys_recvfrom+0x20d/0x300 0x10 is the offset of sock in struct rfcomm_session. With this patch the same run completes with recv() returning 0 and no report, and lockdep stays quiet, confirming rfcomm_mutex is still taken before lock_sock on this path as it is on the thread side. Fixes: bb23c0ab8246 ("Bluetooth: Add support for deferring RFCOMM connection setup") Cc: stable@vger.kernel.org Signed-off-by: Ali Ahmet Memis <ali@iusegentoo.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 43a556b2fd43f2df6dded59c2e26560a27874c24 upstream.

rfcomm_sock_recvmsg() completes a deferred setup by calling
rfcomm_dlc_accept() without holding any RFCOMM lock:

	if (test_and_clear_bit(RFCOMM_DEFER_SETUP, &d->flags)) {
		rfcomm_dlc_accept(d);
		return 0;
	}

and rfcomm_dlc_accept() dereferences the session on its first line:

	struct sock *sk = d->session->sock->sk;

Every other path that touches d->session runs under rfcomm_mutex:
rfcomm_dlc_open(), rfcomm_dlc_close(), rfcomm_dlc_exists(),
rfcomm_dlc_send_rpn(), and the RFCOMM thread through
rfcomm_process_sessions(). rfcomm_connect_ind() is even documented as
"called under rfcomm_lock()". This call site is the only one that skips
it.

The RFCOMM_DEFER_SETUP bit looks like it serialises the accept against
teardown, since __rfcomm_dlc_close() returns early when it wins the
test_and_clear. But rfcomm_recv_disc() forces the state first:

	d->state = BT_CLOSED;
	__rfcomm_dlc_close(d, err);

and the early return only covers BT_CONNECT, BT_CONFIG, BT_OPEN and
BT_CONNECT2. With the state already BT_CLOSED that switch does not
match, the bit is never consulted, and __rfcomm_dlc_close() falls
through to rfcomm_dlc_unlink(), which sets d->session = NULL.

So a remote DISC on a deferred dlc clears the session while leaving
RFCOMM_DEFER_SETUP set. The next recvmsg() then passes the
test_and_clear and dereferences a NULL session. No timing window is
needed: once the DISC has been processed, the dereference is
unconditional.

Give rfcomm_dlc_accept() the same shape as rfcomm_dlc_open() and
rfcomm_dlc_close(): an exported wrapper that takes rfcomm_mutex and
re-checks the session, around a __rfcomm_dlc_accept() that the two
in-core callers, which already hold the mutex, keep using.

Reproduced on a KASAN + PROVE_LOCKING kernel with a BR/EDR peer emulated
over /dev/vhci: the peer brings up an ACL link, opens L2CAP on the
RFCOMM PSM, starts a session, opens a dlc on a channel bound with
BT_DEFER_SETUP, and sends DISC after the socket is accepted. recv() on
the accepted socket then hits:

  Oops: general protection fault
  KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
  RIP: 0010:rfcomm_dlc_accept+0x54/0x350
  Call Trace:
    rfcomm_sock_recvmsg+0x1cd/0x230
    sock_recvmsg+0x166/0x1c0
    __sys_recvfrom+0x20d/0x300

0x10 is the offset of sock in struct rfcomm_session. With this patch the
same run completes with recv() returning 0 and no report, and lockdep
stays quiet, confirming rfcomm_mutex is still taken before lock_sock on
this path as it is on the thread side.

Fixes: bb23c0ab8246 ("Bluetooth: Add support for deferring RFCOMM connection setup")
Cc: stable@vger.kernel.org
Signed-off-by: Ali Ahmet Memis <ali@iusegentoo.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: mgmt: fix pending command UAF in EIR updates 2026-08-23T12:18:37+00:00 Zihan Xi zihanx@nebusec.ai 2026-07-23T16:43:46+00:00 68db850630d05177d450aabe4850027133ed54c5 commit 8f2f62855a41d1730fb9e8122912bd2c8d6bed5d upstream. MGMT_OP_SET_LOCAL_NAME is handled asynchronously on powered controllers and can run set_name_sync(). When the controller is BR/EDR capable, set_name_sync() updates the local name and then rebuilds EIR data through eir_create(). The EIR builder walks hdev->uuids, but the UUID list can be changed and entries can be freed by MGMT_OP_ADD_UUID and MGMT_OP_REMOVE_UUID. pending_eir_or_class() is meant to serialize management commands that can change EIR or the class of device, but it did not include MGMT_OP_SET_LOCAL_NAME. In addition, it walked hdev->mgmt_pending without hdev->mgmt_pending_lock even though pending commands are added and removed under that mutex. A racing command completion can therefore remove and free a pending command while pending_eir_or_class() is still inspecting it, leading to a use-after-free in the pending-command list or allowing a local name update to rebuild EIR while UUID entries are being removed. Take hdev->mgmt_pending_lock while scanning hdev->mgmt_pending and treat MGMT_OP_SET_LOCAL_NAME as an EIR/class-affecting pending command on the powered asynchronous path. Check for a conflicting pending command before copying the new short name so a rejected SET_LOCAL_NAME request does not modify hdev->short_name. Fixes: 6fe26f694c82 ("Bluetooth: MGMT: Protect mgmt_pending list with its own lock") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Assisted-by: Codex:gpt-5.4 Signed-off-by: Zihan Xi <zihanx@nebusec.ai> Signed-off-by: Ren Wei <enjou1224z@gmail.com> Reported-by: Vega <vega@nebusec.ai> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8f2f62855a41d1730fb9e8122912bd2c8d6bed5d upstream.

MGMT_OP_SET_LOCAL_NAME is handled asynchronously on powered controllers
and can run set_name_sync().  When the controller is BR/EDR capable,
set_name_sync() updates the local name and then rebuilds EIR data through
eir_create().  The EIR builder walks hdev->uuids, but the UUID list can
be changed and entries can be freed by MGMT_OP_ADD_UUID and
MGMT_OP_REMOVE_UUID.

pending_eir_or_class() is meant to serialize management commands that
can change EIR or the class of device, but it did not include
MGMT_OP_SET_LOCAL_NAME.  In addition, it walked hdev->mgmt_pending
without hdev->mgmt_pending_lock even though pending commands are added
and removed under that mutex.  A racing command completion can therefore
remove and free a pending command while pending_eir_or_class() is still
inspecting it, leading to a use-after-free in the pending-command list or
allowing a local name update to rebuild EIR while UUID entries are being
removed.

Take hdev->mgmt_pending_lock while scanning hdev->mgmt_pending and treat
MGMT_OP_SET_LOCAL_NAME as an EIR/class-affecting pending command on the
powered asynchronous path.  Check for a conflicting pending command before
copying the new short name so a rejected SET_LOCAL_NAME request does not
modify hdev->short_name.

Fixes: 6fe26f694c82 ("Bluetooth: MGMT: Protect mgmt_pending list with its own lock")
Cc: stable@vger.kernel.org
Reported-by: Vega <vega@nebusec.ai>
Assisted-by: Codex:gpt-5.4
Signed-off-by: Zihan Xi <zihanx@nebusec.ai>
Signed-off-by: Ren Wei <enjou1224z@gmail.com>
Reported-by: Vega <vega@nebusec.ai>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: mgmt: fix locking in unpair_device/disconnect_sync 2026-08-23T12:18:37+00:00 Pauli Virtanen pav@iki.fi 2026-07-10T08:23:41+00:00 74f3e6e21ebc6c418d348f8ce68aef6fe6d82c82 commit 16cd66443957e4ad42155c6fec401012f600c6f8 upstream. Dereferencing RCU-protected pointers outside critical sections is invalid and may lead to UAF. Take hdev->lock for hci_conn lookup and hci_abort_conn(). Don't use RCU to ensure the conn is fully initialized at this point. Fixes: 227a0cdf4a028 ("Bluetooth: MGMT: Fix not generating command complete for MGMT_OP_DISCONNECT") Signed-off-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 16cd66443957e4ad42155c6fec401012f600c6f8 upstream.

Dereferencing RCU-protected pointers outside critical sections is
invalid and may lead to UAF.

Take hdev->lock for hci_conn lookup and hci_abort_conn().  Don't use RCU
to ensure the conn is fully initialized at this point.

Fixes: 227a0cdf4a028 ("Bluetooth: MGMT: Fix not generating command complete for MGMT_OP_DISCONNECT")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: hci_sync: call destroy in hci_cmd_sync_run if immediate 2026-08-23T12:18:37+00:00 Pauli Virtanen pav@iki.fi 2026-03-25T19:07:46+00:00 32279b35dd147700ddd7e5f4811fed2619dbe8c8 commit a834a0b66ec6fb743377201a0f4229bb2503f4ce upstream. hci_cmd_sync_run() may run the work immediately if called from existing sync work (otherwise it queues a new sync work). In this case it fails to call the destroy() function. On immediate run, make it behave same way as if item was queued successfully: call destroy, and return 0. The only callsite is hci_abort_conn() via hci_cmd_sync_run_once(), and this changes its return value. However, its return value is not used except as the return value for hci_disconnect(), and nothing uses the return value of hci_disconnect(). Hence there should be no behavior change anywhere. Fixes: c898f6d7b093b ("Bluetooth: hci_sync: Introduce hci_cmd_sync_run/hci_cmd_sync_run_once") Signed-off-by: Pauli Virtanen <pav@iki.fi> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a834a0b66ec6fb743377201a0f4229bb2503f4ce upstream.

hci_cmd_sync_run() may run the work immediately if called from existing
sync work (otherwise it queues a new sync work). In this case it fails
to call the destroy() function.

On immediate run, make it behave same way as if item was queued
successfully: call destroy, and return 0.

The only callsite is hci_abort_conn() via hci_cmd_sync_run_once(), and
this changes its return value. However, its return value is not used
except as the return value for hci_disconnect(), and nothing uses the
return value of hci_disconnect(). Hence there should be no behavior
change anywhere.

Fixes: c898f6d7b093b ("Bluetooth: hci_sync: Introduce hci_cmd_sync_run/hci_cmd_sync_run_once")
Signed-off-by: Pauli Virtanen <pav@iki.fi>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: hci_sock: Prevent race in socket write iter and sock bind 2026-08-23T12:18:36+00:00 Edward Adam Davis eadavis@qq.com 2025-11-16T09:04:43+00:00 7344feaed3c8aa46d397984ae855e6026d3c3e95 commit 89bb613511cc21ed5ba6bddc1c9b9ae9c0dad392 upstream. There is a potential race condition between sock bind and socket write iter. bind may free the same cmd via mgmt_pending before write iter sends the cmd, just as syzbot reported in UAF[1]. Here we use hci_dev_lock to synchronize the two, thereby avoiding the UAF mentioned in [1]. [1] syzbot reported: BUG: KASAN: slab-use-after-free in mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316 Read of size 8 at addr ffff888077164818 by task syz.0.17/5989 Call Trace: mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316 set_link_security+0x5c2/0x710 net/bluetooth/mgmt.c:1918 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 Allocated by task 5989: mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296 set_link_security+0x557/0x710 net/bluetooth/mgmt.c:1910 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:742 sock_write_iter+0x279/0x360 net/socket.c:1195 Freed by task 5991: mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline] mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257 mgmt_index_removed+0x112/0x2f0 net/bluetooth/mgmt.c:9477 hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314 Fixes: 6fe26f694c82 ("Bluetooth: MGMT: Protect mgmt_pending list with its own lock") Reported-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80 Tested-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com Signed-off-by: Edward Adam Davis <eadavis@qq.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 89bb613511cc21ed5ba6bddc1c9b9ae9c0dad392 upstream.

There is a potential race condition between sock bind and socket write
iter. bind may free the same cmd via mgmt_pending before write iter sends
the cmd, just as syzbot reported in UAF[1].

Here we use hci_dev_lock to synchronize the two, thereby avoiding the
UAF mentioned in [1].

[1]
syzbot reported:
BUG: KASAN: slab-use-after-free in mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
Read of size 8 at addr ffff888077164818 by task syz.0.17/5989
Call Trace:
 mgmt_pending_remove+0x3b/0x210 net/bluetooth/mgmt_util.c:316
 set_link_security+0x5c2/0x710 net/bluetooth/mgmt.c:1918
 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 sock_write_iter+0x279/0x360 net/socket.c:1195

Allocated by task 5989:
 mgmt_pending_add+0x35/0x140 net/bluetooth/mgmt_util.c:296
 set_link_security+0x557/0x710 net/bluetooth/mgmt.c:1910
 hci_mgmt_cmd+0x9c9/0xef0 net/bluetooth/hci_sock.c:1719
 hci_sock_sendmsg+0x6ca/0xef0 net/bluetooth/hci_sock.c:1839
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 sock_write_iter+0x279/0x360 net/socket.c:1195

Freed by task 5991:
 mgmt_pending_free net/bluetooth/mgmt_util.c:311 [inline]
 mgmt_pending_foreach+0x30d/0x380 net/bluetooth/mgmt_util.c:257
 mgmt_index_removed+0x112/0x2f0 net/bluetooth/mgmt.c:9477
 hci_sock_bind+0xbe9/0x1000 net/bluetooth/hci_sock.c:1314

Fixes: 6fe26f694c82 ("Bluetooth: MGMT: Protect mgmt_pending list with its own lock")
Reported-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=9aa47cd4633a3cf92a80
Tested-by: syzbot+9aa47cd4633a3cf92a80@syzkaller.appspotmail.com
Signed-off-by: Edward Adam Davis <eadavis@qq.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: hci_sync: Fix not using correct handle 2026-08-23T12:18:36+00:00 Luiz Augusto von Dentz luiz.von.dentz@intel.com 2024-05-15T14:32:01+00:00 53ca2942c9bec3a12e8071756aa5ad6cdedf53d2 commit 86fbd9f63a6b42b8f158361334f5a25762aea358 upstream. When setting up an advertisement the code shall always attempt to use the handle set by the instance since it may not be equal to the instance ID. Fixes: e77f43d531af ("Bluetooth: hci_core: Fix not handling hdev->le_num_of_adv_sets=1") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 86fbd9f63a6b42b8f158361334f5a25762aea358 upstream.

When setting up an advertisement the code shall always attempt to use
the handle set by the instance since it may not be equal to the instance
ID.

Fixes: e77f43d531af ("Bluetooth: hci_core: Fix not handling hdev->le_num_of_adv_sets=1")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: hci_sync: Fix advertising data UAFs 2026-08-23T12:18:33+00:00 Chengfeng Ye nicoyip.dev@gmail.com 2026-08-11T11:17:28+00:00 565971488191bf54a87a417abafab6ad0de72201 [ Upstream commit cdc36db204ffd97b947d64374cf23a210dc74777 ] hci_find_adv_instance() returns an adv_info pointer that is valid only while hdev->lock is held. The advertising command-sync paths perform instance lookups without that lock and, in some cases, retain the pointer while waiting for a controller response. An advertising termination event can therefore interleave as follows: hci_cmd_sync_work hci_rx_work hci_find_adv_instance() __hci_cmd_sync_status() wait for controller reply hci_dev_lock() hci_remove_adv_instance() kfree(adv) adv->scan_rsp_changed = false KASAN reported: BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88 Workqueue: hci0 hci_cmd_sync_work Call Trace: hci_set_ext_scan_rsp_data_sync+0x2e1/0x300 hci_schedule_adv_instance_sync+0x390/0x4c0 hci_cmd_sync_work+0x173/0x300 Allocated by task 87: hci_add_adv_instance+0x538/0xac0 add_advertising+0x885/0x1160 Freed by task 89: kfree+0x131/0x3c0 hci_remove_adv_instance+0x1d8/0x3b0 hci_le_ext_adv_term_evt+0x17b/0x730 Protect the instance lookup and payload construction in the extended advertising, scan response, and periodic advertising data paths. Snapshot the advertising parameters under hdev->lock, but release the lock before waiting for the controller. Clear advertising-data dirty bits before issuing their commands and restore them after a failure using a fresh lookup. Likewise, update the reported transmit power through a fresh lookup after the parameter command completes. No adv_info pointer then survives an HCI command wait. Fixes: cba6b758711c ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 2") Cc: stable@vger.kernel.org Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com> Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit cdc36db204ffd97b947d64374cf23a210dc74777 ]

hci_find_adv_instance() returns an adv_info pointer that is valid only
while hdev->lock is held.  The advertising command-sync paths perform
instance lookups without that lock and, in some cases, retain the pointer
while waiting for a controller response.

An advertising termination event can therefore interleave as follows:

  hci_cmd_sync_work                 hci_rx_work
  hci_find_adv_instance()
  __hci_cmd_sync_status()
    wait for controller reply       hci_dev_lock()
                                    hci_remove_adv_instance()
                                      kfree(adv)
  adv->scan_rsp_changed = false

KASAN reported:

  BUG: KASAN: slab-use-after-free in hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
  Write of size 1 at addr ffff88810a45d21d by task kworker/u17:0/88
  Workqueue: hci0 hci_cmd_sync_work
  Call Trace:
   hci_set_ext_scan_rsp_data_sync+0x2e1/0x300
   hci_schedule_adv_instance_sync+0x390/0x4c0
   hci_cmd_sync_work+0x173/0x300
  Allocated by task 87:
   hci_add_adv_instance+0x538/0xac0
   add_advertising+0x885/0x1160
  Freed by task 89:
   kfree+0x131/0x3c0
   hci_remove_adv_instance+0x1d8/0x3b0
   hci_le_ext_adv_term_evt+0x17b/0x730

Protect the instance lookup and payload construction in the extended
advertising, scan response, and periodic advertising data paths.  Snapshot
the advertising parameters under hdev->lock, but release the lock before
waiting for the controller.

Clear advertising-data dirty bits before issuing their commands and
restore them after a failure using a fresh lookup.  Likewise, update the
reported transmit power through a fresh lookup after the parameter command
completes.  No adv_info pointer then survives an HCI command wait.

Fixes: cba6b758711c ("Bluetooth: hci_sync: Make use of hci_cmd_sync_queue set 2")
Cc: stable@vger.kernel.org
Suggested-by: Luiz Augusto von Dentz <luiz.dentz@gmail.com>
Signed-off-by: Chengfeng Ye <nicoyip.dev@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: hci_core: Fix not handling hdev->le_num_of_adv_sets=1 2026-08-23T12:18:33+00:00 Luiz Augusto von Dentz luiz.von.dentz@intel.com 2026-08-11T11:17:27+00:00 2a8f0273e2ff6b8bd10fa3f38381c97a1aa105da [ Upstream commit e77f43d531af41e9ce299eab10dcae8fa5dbc293 ] If hdev->le_num_of_adv_sets is set to 1 it means that only handle 0x00 can be used, but since the MGMT interface instances start from 1 (instance 0 means all instances in case of MGMT_OP_REMOVE_ADVERTISING) the code needs to map the instance to handle otherwise users will not be able to advertise as instance 1 would attempt to use handle 0x01. Fixes: 1d0fac2c38ed ("Bluetooth: Use controller sets when available") Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Stable-dep-of: cdc36db204ff ("Bluetooth: hci_sync: Fix advertising data UAFs") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit e77f43d531af41e9ce299eab10dcae8fa5dbc293 ]

If hdev->le_num_of_adv_sets is set to 1 it means that only handle 0x00
can be used, but since the MGMT interface instances start from 1
(instance 0 means all instances in case of MGMT_OP_REMOVE_ADVERTISING)
the code needs to map the instance to handle otherwise users will not be
able to advertise as instance 1 would attempt to use handle 0x01.

Fixes: 1d0fac2c38ed ("Bluetooth: Use controller sets when available")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Stable-dep-of: cdc36db204ff ("Bluetooth: hci_sync: Fix advertising data UAFs")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bluetooth: hci_conn, hci_sync: Use __counted_by() to avoid -Wfamnae warnings 2026-08-23T12:18:33+00:00 Gustavo A. R. Silva gustavoars@kernel.org 2026-08-11T11:17:26+00:00 3cf4a334f90c3ddbb9e62d6183343ac08f49fc23 [ Upstream commit c4585edf708edb5277a3cc4b8581ccb833f3307d ] Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). Also, -Wflex-array-member-not-at-end is coming in GCC-14, and we are getting ready to enable it globally. So, use the `DEFINE_FLEX()` helper for multiple on-stack definitions of a flexible structure where the size of the flexible-array member is known at compile-time, and refactor the rest of the code, accordingly. Notice that, due to the use of `__counted_by()` in `struct hci_cp_le_create_cis`, the for loop in function `hci_cs_le_create_cis()` had to be modified. Once the index `i`, through which `cp->cis[i]` is accessed, falls in the interval [0, cp->num_cis), `cp->num_cis` cannot be decremented all the way down to zero while accessing `cp->cis[]`: net/bluetooth/hci_event.c:4310: 4310 for (i = 0; cp->num_cis; cp->num_cis--, i++) { ... 4314 handle = __le16_to_cpu(cp->cis[i].cis_handle); otherwise, only half (one iteration before `cp->num_cis == i`) or half plus one (one iteration before `cp->num_cis < i`) of the items in the array will be accessed before running into an out-of-bounds issue. So, in order to avoid this, set `cp->num_cis` to zero just after the for loop. Also, make use of `aux_num_cis` variable to update `cmd->num_cis` after a `list_for_each_entry_rcu()` loop. With these changes, fix the following warnings: net/bluetooth/hci_sync.c:1239:56: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] net/bluetooth/hci_sync.c:1415:51: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] net/bluetooth/hci_sync.c:1731:51: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] net/bluetooth/hci_sync.c:6497:45: 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> Stable-dep-of: cdc36db204ff ("Bluetooth: hci_sync: Fix advertising data UAFs") Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit c4585edf708edb5277a3cc4b8581ccb833f3307d ]

Prepare for the coming implementation by GCC and Clang of the
__counted_by attribute. Flexible array members annotated with
__counted_by can have their accesses bounds-checked at run-time
via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE
(for strcpy/memcpy-family functions).

Also, -Wflex-array-member-not-at-end is coming in GCC-14, and we are
getting ready to enable it globally.

So, use the `DEFINE_FLEX()` helper for multiple on-stack definitions
of a flexible structure where the size of the flexible-array member
is known at compile-time, and refactor the rest of the code,
accordingly.

Notice that, due to the use of `__counted_by()` in `struct
hci_cp_le_create_cis`, the for loop in function `hci_cs_le_create_cis()`
had to be modified. Once the index `i`, through which `cp->cis[i]` is
accessed, falls in the interval [0, cp->num_cis), `cp->num_cis` cannot
be decremented all the way down to zero while accessing `cp->cis[]`:

net/bluetooth/hci_event.c:4310:
4310    for (i = 0; cp->num_cis; cp->num_cis--, i++) {
                ...
4314            handle = __le16_to_cpu(cp->cis[i].cis_handle);

otherwise, only half (one iteration before `cp->num_cis == i`) or half
plus one (one iteration before `cp->num_cis < i`) of the items in the
array will be accessed before running into an out-of-bounds issue. So,
in order to avoid this, set `cp->num_cis` to zero just after the for
loop.

Also, make use of `aux_num_cis` variable to update `cmd->num_cis` after
a `list_for_each_entry_rcu()` loop.

With these changes, fix the following warnings:
net/bluetooth/hci_sync.c:1239:56: warning: structure containing a flexible
array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
net/bluetooth/hci_sync.c:1415:51: warning: structure containing a flexible
array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
net/bluetooth/hci_sync.c:1731:51: warning: structure containing a flexible
array member is not at the end of another structure
[-Wflex-array-member-not-at-end]
net/bluetooth/hci_sync.c:6497:45: 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>
Stable-dep-of: cdc36db204ff ("Bluetooth: hci_sync: Fix advertising data UAFs")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>