commit cb19774faa57c51efa189d8b8606aeabccebc53b upstream.
A synchronous HCI command that never receives a response leaves
HCI_CMD_PENDING set: hci_req_cmd_complete() is the only place that clears
it, and it only runs when a response matching the last command sent
arrives.
hci_send_cmd_sync() populates hdev->req_skb only when the flag transitions
from clear to set, while hci_dev_open_sync() and hci_dev_close_sync() drop
req_skb without clearing the flag. After a timeout followed by either, the
two disagree: the flag claims a request is outstanding while req_skb is
NULL. Subsequent synchronous commands are then sent with no req_skb, so
hci_event_packet() has nothing to match an arriving event against, and the
caller times out even though the controller answered.
Commands answered by Command Complete recover on their own, since
hci_req_cmd_complete() clears the flag as a side effect. Drivers using
__hci_cmd_sync_ev() with a custom event do not, because a vendor event
never reaches that path. On a WCN3988 (hci_qca over UART) this makes a
controller firmware hang unrecoverable: the driver injects a hardware
error and re-runs qca_setup(), qca_read_soc_version() waits for
HCI_EV_VENDOR, the reply arrives within 4 ms and is discarded, and every
retry fails the same way. The adapter is left down until the driver is
unbound and rebound, or power is removed.
Clear the flag wherever the last request is dropped, restoring the
invariant that req_skb is non-NULL exactly when HCI_CMD_PENDING is set.
Verified on hardware by forcing a command timeout: without this change
setup fails on every attempt, with it setup succeeds on the first.
Fixes: 2615fd9a7c25 ("Bluetooth: hci_sync: Fix overwriting request callback")
Cc: stable@vger.kernel.org
Signed-off-by: Ibrahim Abdelkader <iabdelka@qti.qualcomm.com>
Signed-off-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 941929abe5feaed672b9a52e330e547d333240c6 upstream.
le_conn_complete_evt() clears HCI_LE_ADV before looking at the event
status, on the premise stated in its comment that all controllers stop
advertising when a connection is created.
That premise only holds when a connection was actually created. On a
non-zero status none was, and the controller is still advertising: after
the host issues LE Create Connection Cancel the event arrives with
Unknown Connection Identifier (0x02), and a connection timeout behaves
the same way. Clearing the flag there leaves the host believing
advertising is off while the controller has it on.
It is also wrong for extended advertising, where several sets can be
advertising at once. hci_cc_le_set_ext_adv_enable() is careful about
this - on disabling one set it walks hdev->adv_instances and only clears
HCI_LE_ADV once no instance is still enabled. The unconditional clear
here discards that bookkeeping, so one set connecting drops the flag
while the others keep advertising.
The direction of the error matters. A flag left set is self-correcting:
hci_disable_advertising_sync() sends LE Set Advertising Enable(0) and
the command complete puts the state back. A flag left clear is not,
because that same function returns early without sending anything while
the flag is clear:
- LE Set Advertising Parameters is then sent to a controller that is
still advertising, and is correctly rejected with Command Disallowed
(0x0c);
- hci_enable_advertising_sync() returns at that point, before the
LE Set Advertising Enable that would set HCI_LE_ADV again.
On a controller without LE Extended Advertising that is reachable from
here: hci_schedule_adv_instance_sync() re-arms adv_instance_expire every
HCI_DEFAULT_ADV_DURATION (2 s) and its "already advertising" shortcut
tests HCI_LE_ADV, which can no longer become true, so the parameter
write is retried for as long as advertising is configured:
Bluetooth: hci0: Opcode 0x2006 failed: -16
Only clear the flag when a connection was established.
Note this is not on its own sufficient to stop that retry loop - the
redundant enable queued by hci_le_conn_failed() clears HCI_LE_ADV itself
and recreates the same mismatch, which patch 1 addresses. This patch
fixes the event handler reporting a state the controller is not in.
Verified on the affected device (BCM43455, legacy advertising only) with
this patch and patch 1 applied. A 221 s btmon capture with an out-of-range
peer at -90 dBm contains two outgoing connection attempts that the host
cancelled, each producing exactly the event this patch changes:
< LE Set Advertising Parameters 0x2006 Success
< LE Set Advertising Enable 0x200a Success
< LE Create Connection Cancel 0x200e Success
> LE Connection Complete Unknown Connection Identifier (0x02), central
Nothing follows either one; the next command is an unrelated scan restart
70 ms later. Over the whole capture: 7 LE Set Advertising Parameters sent,
all Success; 10 LE Set Advertising Enable, all Success; no Command
Disallowed of any opcode, and no 2 s cadence anywhere. Two central
connections to other peers completed normally afterwards, with feature
exchange and a connection parameter update, so advertising was still live
across the cancelled attempts.
The extended advertising case above is a code argument, not a measurement:
this controller has no LE Extended Advertising, so that path is not
exercised by the capture.
Fixes: fbd96c151cdc ("Bluetooth: Fix clearing HCI_LE_ADV for LE connections")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5 btmon
Signed-off-by: Valentin Kindschi <valentin.kindschi@fiveco.ch>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit f5afdff569a09d1cb8cf19826199d024725576cb upstream.
BT enable fails intermittently with -ETIMEDOUT (-110). The kernel log
shows the HCI Read Local Version command was sent and the firmware
replied with status 0x00 (logged by hci_req_cmd_complete() BT_DBG),
but the waiter in __hci_cmd_sync_sk() never woke up and timed out
after 10 s:
bluetooth hci0: Opcode 0xfc00 // __hci_cmd_sync_sk
bluetooth hci0: opcode 0xfc00 plen 1 // hci_cmd_sync_add
bluetooth hci0: skb len 4 // hci_cmd_sync_alloc
bluetooth hci0: length 1 // hci_req_sync_run
Bluetooth: hci0 cmd_cnt 1 cmd queued 1 // hci_cmd_work
Bluetooth: hci0 type 1 len 4 // hci_send_frame
Bluetooth: opcode 0xfc00 status 0x00 // hci_req_cmd_complete
<-- req_skb NULL: req_complete_skb not set,
hci_cmd_sync_complete() never called,
req_status stays HCI_REQ_PEND -->
<-- 10 s later: wait_event_interruptible_timeout expires -->
bluetooth hci0: end: err -110 // __hci_cmd_sync_sk
The root cause is that hci_send_cmd_sync() clones the sent command
into hdev->req_skb so that hci_req_cmd_complete() can locate the
registered completion callback. Under memory pressure this
skb_clone() fails, leaving hdev->req_skb NULL. The firmware reply
is received and processed, but hci_req_cmd_complete() finds NULL
req_skb, so hci_cmd_sync_complete() is never called, req_status
stays HCI_REQ_PEND, and the waiter times out with -ETIMEDOUT.
req_skb is only used to read bt_cb(skb)->hci callbacks and opcode --
it is never modified. Replace skb_clone() with skb_get(), which
simply increments the reference count of hdev->sent_cmd without
allocating new memory and therefore cannot fail.
This issue was first observed as a use-after-free in ttyport_close()
when ttyport_open() failed, which was investigated in an earlier
patch series [1]. That investigation led to the discovery of the
true root cause described above.
[1] https://lore.kernel.org/all/20250430111617.1151390-1-quic_cxin@quicinc.com/
Fixes: 2615fd9a7c25 ("Bluetooth: hci_sync: Fix overwriting request callback")
Cc: stable@vger.kernel.org
Signed-off-by: Xin Chen <xin.chen2@oss.qualcomm.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ed5fb41d3b6b6e665e7f97fd54bd1f9531c7477f upstream.
hci_le_conn_failed() unconditionally calls hci_enable_advertising(),
although its own comment states advertising should be re-enabled only
when the failed attempt was made as a peripheral.
hci_le_conn_failed() is reached from hci_conn_failed() for every failed
LE connection, including outgoing central connections. For a central
attempt this enable is redundant: hci_le_create_conn_sync() already
restores advertising via hci_resume_advertising_sync() in its done:
block. Because hci_enable_advertising() only queues the work on
cmd_sync_work, it runs *after* that resume has already succeeded and
set HCI_LE_ADV.
The resulting HCI sequence, captured on a BCM43455 (no LE Extended
Advertising, so legacy advertising is used):
LE Create Connection Status Success
... 13.8 s, peer never answers ...
LE Set Advertising Parameters (0x2006) Success <- done: resume,
LE Set Advertising Enable (0x200a) Success HCI_LE_ADV set
LE Create Connection Cancel (0x200e) Success
LE Connection Complete Unknown Conn Id
LE Set Advertising Parameters (0x2006) Command Disallowed (0x0c)
The last command is the queued enable from hci_le_conn_failed() running
as a second hci_enable_advertising_sync() pass. It clears HCI_LE_ADV
(hci_sync.c, "Clear the HCI_LE_ADV bit temporarily"), then sends
LE Set Advertising Parameters while the controller is still advertising,
which the controller correctly rejects with Command Disallowed.
The disable-first call at the top of hci_enable_advertising_sync()
cannot prevent this: hci_disable_advertising_sync() returns early
without sending anything when HCI_LE_ADV is clear, so it is a no-op
exactly when the flag is wrong.
hci_enable_advertising_sync() then returns without sending LE Set
Advertising Enable, so HCI_LE_ADV is never set again. The legacy
software rotation loop re-arms hci_schedule_adv_instance_sync() every
HCI_DEFAULT_ADV_DURATION (2 s), and its "already advertising" shortcut
tests HCI_LE_ADV, which can no longer become true. The command is
therefore retried every 2 s indefinitely:
Bluetooth: hci0: Opcode 0x2006 failed: -16
Observed on a gateway as 5326 occurrences over 3 hours, ending only when
bluetoothd was restarted. Connection attempts that succeed do not call
hci_le_conn_failed() and never trigger this.
Add the role test the comment already describes. Both other
hci_enable_advertising() call sites reached from a failed/closed LE
connection (hci_cs_disconnect() and hci_disconn_complete_evt()) already
guard on conn->role == HCI_ROLE_SLAVE; this one was missed.
Reproducing needs legacy advertising (ext_adv_capable() false, so the
software rotation loop is used), simultaneous peripheral advertising and
outgoing central connects, and a central connect that times out rather
than failing fast.
The Fixes tag points at the commit that introduced the advertising
restart into this path for the directed-advertising (peripheral) case;
the role test that the later commit 0b1db38ca26b ("Bluetooth: Fix check
for direct advertising") added to the sibling paths was never applied
here.
Fixes: 3c857757ef6e ("Bluetooth: Add directed advertising support through connect()")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5 btmon
Signed-off-by: Valentin Kindschi <valentin.kindschi@fiveco.ch>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 759c185d0bbdb131357408f50b8735e04ed3caff upstream.
rfcomm_security_cfm() looks up a session on session_list and then walks
its DLC list without holding rfcomm_mutex. Since RFCOMM session teardown
uses rfcomm_mutex, krfcommd can close and free the same session and DLCs
concurrently:
hci_rx_work krfcommd
----------- ---------
rfcomm_session_get()
rfcomm_lock()
rfcomm_session_close()
rfcomm_dlc_unlink()
rfcomm_session_del()
kfree(s)
rfcomm_unlock()
walk s->dlcs
The callback can then read a freed session list head and touch freed DLCs
while updating their flags or timers.
Serialize the session lookup and DLC traversal in rfcomm_security_cfm()
with rfcomm_mutex. This matches the existing RFCOMM session lifetime
rules and prevents concurrent rfcomm_session_del() / rfcomm_dlc_unlink()
from tearing the objects down while the callback is using them.
KASAN reported:
BUG: KASAN: slab-use-after-free in rfcomm_security_cfm+0x41c/0x440
Read of size 8 at addr ffff888111fb3960 by task kworker/u17:1/89
Workqueue: hci0 hci_rx_work
Call Trace:
rfcomm_security_cfm+0x41c/0x440
hci_encrypt_cfm+0x139/0x590
hci_encrypt_change_evt+0x37b/0xc40
hci_event_packet+0x71b/0xb20
hci_rx_work+0x293/0x730
Allocated by task 69:
rfcomm_session_add+0x9e/0x2f0
rfcomm_run+0x44b/0x41e0
Freed by task 69:
kfree+0x131/0x3c0
rfcomm_session_del+0x188/0x220
rfcomm_run+0x1985/0x41e0
Fixes: 08c30aca9e698faddebd34f81e1196295f9dc063 ("Bluetooth: Remove RFCOMM session refcnt")
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 560bef609fa5992745929e8d7d458b9d88dd2830 upstream.
iso_conn_ready() looks up the BIS listener socket with iso_get_sock(),
which takes a reference, and then, without re-checking its state,
creates a child socket from it:
parent = iso_get_sock(hdev, ...);
if (!parent)
return;
lock_sock(parent);
sk = iso_sock_alloc(sock_net(parent), NULL, BTPROTO_ISO, ...);
...
iso_chan_add(conn, sk, parent);
...
release_sock(parent);
sock_put(parent);
If the listener socket is closed concurrently, between iso_get_sock()
and lock_sock(), the reference taken by iso_get_sock() may be the last
one: the close path drops the link-list reference, and once
iso_conn_ready() drops its own reference at the end of the function the
socket is freed. The child socket, however, is already linked to the
freed parent, and a later disconnect of the child runs iso_chan_del()
-> bt_accept_unlink(), which dereferences the dangling parent pointer
into the freed accept queue (a use-after-free). The same dangling
pointer is also dereferenced through parent->***() in
iso_chan_del().
Fix it the same way the connected (non-BIS) path was fixed in commit
0d255e63fcf3 ("Bluetooth: ISO: hold sk properly in iso_conn_ready"):
after taking the socket lock, re-check that the parent is still a
listening, alive socket, and bail out otherwise.
Fixes: ccf74f2390d60 ("Bluetooth: Add BTPROTO_ISO socket type")
Cc: stable@vger.kernel.org
Signed-off-by: Hang Nan <2122295973@qq.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4beb198bc59b242404a47c21990bc84165052c8a upstream.
eir_get_service_data() walks the advertising data for a Service Data
field with a matching UUID. On a mismatch it advances:
eir += dlen;
eir_len -= dlen;
eir_get_data() reports dlen as the field's data length, but the field
spans dlen + 2 bytes once its length and type bytes count, and more
when non-Service-Data fields were skipped to reach it. The pointer
lands correctly on the next field. eir_len does not, and the shortfall
compounds across fields until eir_get_data() reads the length and type
bytes of a "field" past the end of the buffer.
For an ISO broadcast sink that buffer is hcon->le_per_adv_data[], filled
from the periodic advertising reports of a remote broadcaster. A PA
payload packed with mismatching Service Data fields walks off the array
into the rest of struct hci_conn. A drifted field that matches the BAA
UUID puts those bytes in iso_pi(sk)->base, where user space reads them
back with getsockopt(BT_ISO_BASE).
Recompute eir_len from the end of the buffer each iteration.
Fixes: 8f9ae5b3ae80 ("Bluetooth: eir: Add helpers for managing service data")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-5
Signed-off-by: HyeongJun An <sammiee5311@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5d95286b6d6e8f1d304da7522bfa6860fc017e48 upstream.
mgmt_hci_cmd_sync() checks that the message length agrees with params_len
but puts no upper bound on it. params_len is __le16 while the parameter
length in the HCI command header is a u8:
struct hci_command_hdr {
__le16 opcode;
__u8 plen;
} __packed;
hci_cmd_sync_alloc() assigns one to the other:
hdr->plen = plen;
if (plen)
skb_put_data(skb, param, plen);
so a params_len of 256 leaves plen at 0 while all 256 bytes are still
appended. The frame handed to the driver then declares no parameters and
carries 256 of them. On a length framed transport such as H:4 the
controller takes the trailing bytes as the start of the next packet.
The mgmt socket MTU is HCI_MAX_FRAME_SIZE, so params_len can reach about
1KB this way. Commit 03f1700b9b4d ("Bluetooth: MGMT: reject malformed
HCI_CMD_SYNC commands") only made params_len agree with the message
length, a value that fits the message but not the header field is still
accepted.
Reject params_len that does not fit the header field.
Fixes: 827af4787e74 ("Bluetooth: MGMT: Add initial implementation of MGMT_OP_HCI_CMD_SYNC")
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 884cf2cc957da7ac178a0e6c6c69ddfec0481cc8 upstream.
iso_sock_getname() fills a struct sockaddr_iso in place and returns its
size without clearing it first, so bytes it does not write are copied to
user space from the kernel stack. The getsockname(2) and getpeername(2)
paths both run through do_getsockname(), which hands getname() an
uninitialized sockaddr_storage on the stack and copies back up to the
number of bytes getname() returns, so the driver has to initialize every
byte it accounts for.
Two ranges are left uninitialized:
- struct sockaddr_iso is 10 bytes but only 9 are written (family,
iso_bdaddr, iso_bdaddr_type), leaking the trailing pad byte on every
call.
- for a broadcast peer (BIS_LINK or PA_LINK) the returned length grows
by sizeof(struct sockaddr_iso_bc), but only bc_sid, bc_num_bis and
bc_bis are filled; bc_bdaddr and bc_bdaddr_type, the first 7 bytes of
that structure, are never written.
An unprivileged process can open a BTPROTO_ISO socket and reach the pad
leak with getsockname(); the broadcast leak needs an established BIS/PA
connection. l2cap and rfcomm already memset their sockaddr in getname
for the same reason; do the same here.
Fixes: ccf74f2390d6 ("Bluetooth: Add BTPROTO_ISO socket type")
Fixes: 0a766a0affb5 ("Bluetooth: ISO: Fix getpeername not returning sockaddr_iso_bc fields")
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 9838a80096ba472d5e03057136a112631aabae6e upstream.
iso_sock_recvmsg() handles the deferred setup of a broadcast sink by
dropping the socket lock, calling iso_conn_big_sync() and taking the
lock again:
release_sock(sk);
iso_conn_big_sync(sk);
lock_sock(sk);
sk->sk_state = BT_LISTEN;
The state is written unconditionally, but iso_conn_big_sync() returns
void and has paths that do nothing at all: hci_get_route() may fail, and
after re-acquiring the socket lock the connection may already be gone,
in which case it bails out without ever issuing an LE BIG Create Sync.
While the lock is dropped the connection can be torn down, for example
when the controller reports HCI_EV_LE_PA_SYNC_LOST:
hci_le_pa_sync_lost_evt()
hci_disconn_cfm() -> iso_disconn_cfm() -> iso_conn_del()
iso_chan_del()
iso_pi(sk)->conn = NULL
sk->sk_state = BT_CLOSED
sock_set_flag(sk, SOCK_ZAPPED)
iso_conn_big_sync() then finds conn == NULL and returns, but the caller
still overwrites the BT_CLOSED that iso_chan_del() has just set. The
socket ends up marked BT_LISTEN with no connection, so recvmsg() reports
success for a setup that never happened and a later accept() waits for
BIS connections that can never arrive instead of failing.
A concurrent shutdown() reaches the same write by another route:
__iso_sock_close() takes the BT_CONNECT2 PA sync path to
iso_sock_disconn(), which sets BT_DISCONN but leaves conn and
conn->hcon in place, so iso_conn_big_sync() succeeds and BT_LISTEN is
written over BT_DISCONN. Both the BT_CONNECT2 and the BT_CONNECTED case
write the state the same way.
Let iso_conn_big_sync() report whether the BIG sync was started, and
only move the socket to BT_LISTEN when it was and when the state has not
changed while the lock was dropped, mirroring what the BT_CONNECT case
of the same switch already does with iso_connect_cis(). Both conditions
are needed, the error alone does not cover the shutdown() race.
This corrupts the socket state machine only, it is not a memory safety
issue. KASAN and lockdep stayed quiet in all of the runs below.
Reproduced with an emulated controller over /dev/vhci on a KASAN +
PROVE_LOCKING kernel. A PA sync broadcast sink socket is driven to
BT_CONNECT2 and recvmsg() on it is raced against teardown, with a debug
delay inside the lock-dropped section to widen the window:
- HCI_EV_LE_PA_SYNC_LOST injected: 64 of 64 rounds left the socket in
BT_LISTEN with the connection gone, recvmsg() returned 0 and accept()
on that fd returned EAGAIN, which iso_sock_accept() can only do while
the socket is BT_LISTEN. With this patch, 0 of 64, recvmsg() returns
an error and accept() returns EBADFD.
- shutdown() instead of a controller event: 24 of 32 rounds wedged in
BT_LISTEN, 0 of 32 with this patch. With only the error check in
place and a short window, one round still wedged while recvmsg()
returned 0, which is the case the state re-check covers.
An unraced control round behaves the same before and after: recvmsg()
returns 0, the socket reaches BT_LISTEN and an LE BIG Create Sync is
issued.
Fixes: 7a17308c1788 ("Bluetooth: iso: Fix circular lock in iso_conn_big_sync")
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>