linux-stable/net/bluetooth
Duoming Zhou e97e16433e Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout
[ Upstream commit adf0398cee ]

There is a race condition between l2cap_chan_timeout() and
l2cap_chan_del(). When we use l2cap_chan_del() to delete the
channel, the chan->conn will be set to null. But the conn could
be dereferenced again in the mutex_lock() of l2cap_chan_timeout().
As a result the null pointer dereference bug will happen. The
KASAN report triggered by POC is shown below:

[  472.074580] ==================================================================
[  472.075284] BUG: KASAN: null-ptr-deref in mutex_lock+0x68/0xc0
[  472.075308] Write of size 8 at addr 0000000000000158 by task kworker/0:0/7
[  472.075308]
[  472.075308] CPU: 0 PID: 7 Comm: kworker/0:0 Not tainted 6.9.0-rc5-00356-g78c0094a146b #36
[  472.075308] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4
[  472.075308] Workqueue: events l2cap_chan_timeout
[  472.075308] Call Trace:
[  472.075308]  <TASK>
[  472.075308]  dump_stack_lvl+0x137/0x1a0
[  472.075308]  print_report+0x101/0x250
[  472.075308]  ? __virt_addr_valid+0x77/0x160
[  472.075308]  ? mutex_lock+0x68/0xc0
[  472.075308]  kasan_report+0x139/0x170
[  472.075308]  ? mutex_lock+0x68/0xc0
[  472.075308]  kasan_check_range+0x2c3/0x2e0
[  472.075308]  mutex_lock+0x68/0xc0
[  472.075308]  l2cap_chan_timeout+0x181/0x300
[  472.075308]  process_one_work+0x5d2/0xe00
[  472.075308]  worker_thread+0xe1d/0x1660
[  472.075308]  ? pr_cont_work+0x5e0/0x5e0
[  472.075308]  kthread+0x2b7/0x350
[  472.075308]  ? pr_cont_work+0x5e0/0x5e0
[  472.075308]  ? kthread_blkcg+0xd0/0xd0
[  472.075308]  ret_from_fork+0x4d/0x80
[  472.075308]  ? kthread_blkcg+0xd0/0xd0
[  472.075308]  ret_from_fork_asm+0x11/0x20
[  472.075308]  </TASK>
[  472.075308] ==================================================================
[  472.094860] Disabling lock debugging due to kernel taint
[  472.096136] BUG: kernel NULL pointer dereference, address: 0000000000000158
[  472.096136] #PF: supervisor write access in kernel mode
[  472.096136] #PF: error_code(0x0002) - not-present page
[  472.096136] PGD 0 P4D 0
[  472.096136] Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI
[  472.096136] CPU: 0 PID: 7 Comm: kworker/0:0 Tainted: G    B              6.9.0-rc5-00356-g78c0094a146b #36
[  472.096136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu4
[  472.096136] Workqueue: events l2cap_chan_timeout
[  472.096136] RIP: 0010:mutex_lock+0x88/0xc0
[  472.096136] Code: be 08 00 00 00 e8 f8 23 1f fd 4c 89 f7 be 08 00 00 00 e8 eb 23 1f fd 42 80 3c 23 00 74 08 48 88
[  472.096136] RSP: 0018:ffff88800744fc78 EFLAGS: 00000246
[  472.096136] RAX: 0000000000000000 RBX: 1ffff11000e89f8f RCX: ffffffff8457c865
[  472.096136] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88800744fc78
[  472.096136] RBP: 0000000000000158 R08: ffff88800744fc7f R09: 1ffff11000e89f8f
[  472.096136] R10: dffffc0000000000 R11: ffffed1000e89f90 R12: dffffc0000000000
[  472.096136] R13: 0000000000000158 R14: ffff88800744fc78 R15: ffff888007405a00
[  472.096136] FS:  0000000000000000(0000) GS:ffff88806d200000(0000) knlGS:0000000000000000
[  472.096136] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  472.096136] CR2: 0000000000000158 CR3: 000000000da32000 CR4: 00000000000006f0
[  472.096136] Call Trace:
[  472.096136]  <TASK>
[  472.096136]  ? __die_body+0x8d/0xe0
[  472.096136]  ? page_fault_oops+0x6b8/0x9a0
[  472.096136]  ? kernelmode_fixup_or_oops+0x20c/0x2a0
[  472.096136]  ? do_user_addr_fault+0x1027/0x1340
[  472.096136]  ? _printk+0x7a/0xa0
[  472.096136]  ? mutex_lock+0x68/0xc0
[  472.096136]  ? add_taint+0x42/0xd0
[  472.096136]  ? exc_page_fault+0x6a/0x1b0
[  472.096136]  ? asm_exc_page_fault+0x26/0x30
[  472.096136]  ? mutex_lock+0x75/0xc0
[  472.096136]  ? mutex_lock+0x88/0xc0
[  472.096136]  ? mutex_lock+0x75/0xc0
[  472.096136]  l2cap_chan_timeout+0x181/0x300
[  472.096136]  process_one_work+0x5d2/0xe00
[  472.096136]  worker_thread+0xe1d/0x1660
[  472.096136]  ? pr_cont_work+0x5e0/0x5e0
[  472.096136]  kthread+0x2b7/0x350
[  472.096136]  ? pr_cont_work+0x5e0/0x5e0
[  472.096136]  ? kthread_blkcg+0xd0/0xd0
[  472.096136]  ret_from_fork+0x4d/0x80
[  472.096136]  ? kthread_blkcg+0xd0/0xd0
[  472.096136]  ret_from_fork_asm+0x11/0x20
[  472.096136]  </TASK>
[  472.096136] Modules linked in:
[  472.096136] CR2: 0000000000000158
[  472.096136] ---[ end trace 0000000000000000 ]---
[  472.096136] RIP: 0010:mutex_lock+0x88/0xc0
[  472.096136] Code: be 08 00 00 00 e8 f8 23 1f fd 4c 89 f7 be 08 00 00 00 e8 eb 23 1f fd 42 80 3c 23 00 74 08 48 88
[  472.096136] RSP: 0018:ffff88800744fc78 EFLAGS: 00000246
[  472.096136] RAX: 0000000000000000 RBX: 1ffff11000e89f8f RCX: ffffffff8457c865
[  472.096136] RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffff88800744fc78
[  472.096136] RBP: 0000000000000158 R08: ffff88800744fc7f R09: 1ffff11000e89f8f
[  472.132932] R10: dffffc0000000000 R11: ffffed1000e89f90 R12: dffffc0000000000
[  472.132932] R13: 0000000000000158 R14: ffff88800744fc78 R15: ffff888007405a00
[  472.132932] FS:  0000000000000000(0000) GS:ffff88806d200000(0000) knlGS:0000000000000000
[  472.132932] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  472.132932] CR2: 0000000000000158 CR3: 000000000da32000 CR4: 00000000000006f0
[  472.132932] Kernel panic - not syncing: Fatal exception
[  472.132932] Kernel Offset: disabled
[  472.132932] ---[ end Kernel panic - not syncing: Fatal exception ]---

Add a check to judge whether the conn is null in l2cap_chan_timeout()
in order to mitigate the bug.

Fixes: 3df91ea20e ("Bluetooth: Revert to mutexes from RCU list")
Signed-off-by: Duoming Zhou <duoming@zju.edu.cn>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2024-05-17 11:50:57 +02:00
..
bnep exit: Rename module_put_and_exit to module_put_and_kthread_exit 2024-04-10 16:18:55 +02:00
cmtp exit: Rename module_put_and_exit to module_put_and_kthread_exit 2024-04-10 16:18:55 +02:00
hidp exit: Rename module_put_and_exit to module_put_and_kthread_exit 2024-04-10 16:18:55 +02:00
rfcomm Bluetooth: rfcomm: Fix null-ptr-deref in rfcomm_check_security 2024-03-26 18:21:13 -04:00
6lowpan.c Bluetooth: 6LoWPAN: add missing hci_dev_put() in get_l2cap_conn() 2022-12-14 11:37:24 +01:00
Kconfig
Makefile
a2mp.c
a2mp.h
af_bluetooth.c Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg 2024-01-05 15:13:39 +01:00
amp.c
amp.h
aosp.c
aosp.h
ecdh_helper.c
ecdh_helper.h
hci_conn.c Bluetooth: Fix bogus check for re-auth no supported with non-ssp 2024-01-25 14:52:40 -08:00
hci_core.c Bluetooth: hci_core: Fix possible buffer overflow 2024-03-26 18:21:22 -04:00
hci_debugfs.c Bluetooth: Fix TOCTOU in HCI debugfs implementation 2024-04-10 16:19:37 +02:00
hci_debugfs.h
hci_event.c Bluetooth: hci_event: set the conn encrypted before conn establishes 2024-04-10 16:19:36 +02:00
hci_request.c Bluetooth: Fix memory leak in hci_req_sync_complete() 2024-04-17 11:15:13 +02:00
hci_request.h
hci_sock.c Bluetooth: hci_sock: Correctly bounds check and pad HCI_MON_NEW_INDEX name 2023-10-25 11:59:04 +02:00
hci_sysfs.c Bluetooth: Fix double free in hci_conn_cleanup 2023-11-28 16:56:16 +00:00
l2cap_core.c Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout 2024-05-17 11:50:57 +02:00
l2cap_sock.c Bluetooth: Fix type of len in {l2cap,sco}_sock_getsockopt_old() 2024-05-02 16:24:48 +02:00
leds.c
leds.h
lib.c
mgmt.c Bluetooth: MGMT/SMP: Fix address type when using SMP over BREDR/LE 2024-01-05 15:13:34 +01:00
mgmt_config.c
mgmt_config.h
mgmt_util.c
mgmt_util.h
msft.c
msft.h
sco.c Bluetooth: Fix use-after-free bugs caused by sco_sock_timeout 2024-05-17 11:50:57 +02:00
selftest.c
selftest.h
smp.c Bluetooth: MGMT/SMP: Fix address type when using SMP over BREDR/LE 2024-01-05 15:13:34 +01:00
smp.h