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 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 c783399efc22d035443f1dfbf2a09bf9562aaa5e upstream.

rfcomm_tty_set_termios() tests dlc->session without rfcomm_mutex and
later passes the pointer to rfcomm_send_rpn(). The latter dereferences
both session->initiator and session->sock. Meanwhile, krfcommd can
unlink the DLC and free the session while holding rfcomm_mutex.

The race can proceed as follows:

  TTY ioctl task                 krfcommd
  --------------                 --------
  load dlc->session
  enter rfcomm_send_rpn()
                                 lock rfcomm_mutex
                                 clear dlc->session
                                 free session
                                 unlock rfcomm_mutex
  read session->initiator

KASAN reported:

  BUG: KASAN: slab-use-after-free in rfcomm_send_rpn+0x297/0x2a0
  Read of size 4 at addr ffff88810012a850 by task poc/92

  Call Trace:
   rfcomm_send_rpn+0x297/0x2a0
   rfcomm_tty_set_termios+0x50d/0x850
   tty_set_termios+0x596/0x950
   set_termios+0x46a/0x6e0
   tty_mode_ioctl+0x152/0xbd0
   tty_ioctl+0x915/0x1240
   __x64_sys_ioctl+0x134/0x1c0

  Allocated by task 92:
   rfcomm_session_add+0x9e/0x2e0
   rfcomm_dlc_open+0x8b1/0xe00
   rfcomm_dev_activate+0x85/0x1a0
   rfcomm_tty_open+0x90/0x280

  Freed by task 68:
   kfree+0x131/0x3c0
   rfcomm_session_del+0x119/0x180
   rfcomm_run+0x737/0x4710

Add rfcomm_dlc_send_rpn(), which holds rfcomm_mutex while it verifies
that the DLC is still attached and sends the RPN frame. Have the TTY
path use the helper and drop its unlocked session check. This keeps the
session valid through both the frame construction and socket send.

Fixes: 3a5e903c09ae ("[Bluetooth]: Implement RFCOMM remote port negotiation")
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>

[ Upstream commit 23882b828c3c8c51d0c946446a396b10abb3b16b ]

The RFCOMM MCC handlers cast skb->data to protocol-specific structs
without validating skb->len first. A malicious remote device can send
truncated MCC frames and trigger out-of-bounds reads in these handlers.

Fix this by using skb_pull_data() to validate and access the required
data before dereferencing it.

rfcomm_recv_rpn() requires special handling since ETSI TS 07.10 allows
1-byte RPN requests. Handle this by validating only the DLCI byte first,
and validating the full struct only when len > 1.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Suggested-by: Muhammad Bilal <meatuni001@gmail.com>
Signed-off-by: SeungJu Cheon <suunj1331@gmail.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Found by codespell.

Signed-off-by: Bastien Nocera <hadess@hadess.net>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.

Conversion was done with coccinelle plus manual fixups where necessary.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

This reverts commit 4d94f05558271654670d18c26c912da0c1c15549 which has
problems (see [1]) and is no longer needed since 581dd2dc168f
("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: 4d94f0555827 ("Bluetooth: hci_core: Fix sleeping function called from invalid context")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

This reworks hci_cb_list to not use mutex hci_cb_list_lock to avoid bugs
like the bellow:

BUG: sleeping function called from invalid context at kernel/locking/mutex.c:585
in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 5070, name: kworker/u9:2
preempt_count: 0, expected: 0
RCU nest depth: 1, expected: 0
4 locks held by kworker/u9:2/5070:
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3229 [inline]
 #0: ffff888015be3948 ((wq_completion)hci0#2){+.+.}-{0:0}, at: process_scheduled_works+0x8e0/0x1770 kernel/workqueue.c:3335
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3230 [inline]
 #1: ffffc90003b6fd00 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0}, at: process_scheduled_works+0x91b/0x1770 kernel/workqueue.c:3335
 #2: ffff8880665d0078 (&hdev->lock){+.+.}-{3:3}, at: hci_le_create_big_complete_evt+0xcf/0xae0 net/bluetooth/hci_event.c:6914
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire include/linux/rcupdate.h:298 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: rcu_read_lock include/linux/rcupdate.h:750 [inline]
 #3: ffffffff8e132020 (rcu_read_lock){....}-{1:2}, at: hci_le_create_big_complete_evt+0xdb/0xae0 net/bluetooth/hci_event.c:6915
CPU: 0 PID: 5070 Comm: kworker/u9:2 Not tainted 6.8.0-syzkaller-08073-g480e035fc4c7 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Workqueue: hci0 hci_rx_work
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
 __might_resched+0x5d4/0x780 kernel/sched/core.c:10187
 __mutex_lock_common kernel/locking/mutex.c:585 [inline]
 __mutex_lock+0xc1/0xd70 kernel/locking/mutex.c:752
 hci_connect_cfm include/net/bluetooth/hci_core.h:2004 [inline]
 hci_le_create_big_complete_evt+0x3d9/0xae0 net/bluetooth/hci_event.c:6939
 hci_event_func net/bluetooth/hci_event.c:7514 [inline]
 hci_event_packet+0xa53/0x1540 net/bluetooth/hci_event.c:7569
 hci_rx_work+0x3e8/0xca0 net/bluetooth/hci_core.c:4171
 process_one_work kernel/workqueue.c:3254 [inline]
 process_scheduled_works+0xa00/0x1770 kernel/workqueue.c:3335
 worker_thread+0x86d/0xd70 kernel/workqueue.c:3416
 kthread+0x2f0/0x390 kernel/kthread.c:388
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243
 </TASK>

Reported-by: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com
Tested-by: syzbot+2fb0835e0c9cefc34614@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=2fb0835e0c9cefc34614
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.

auto-generated by the following:

for i in `git grep -l -w asm/unaligned.h`; do
	sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
	sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h