linux/net/bluetooth
Duoming Zhou adf0398cee Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout
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>
2024-05-03 13:05:54 -04:00
..
bnep Bluetooth: bnep: Fix out-of-bound access 2024-03-06 17:26:24 -05:00
cmtp Merge branch 'signal-for-v5.17' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2022-01-17 05:49:30 +02:00
hidp Bluetooth: Init sk_peer_* on bt_sock_alloc 2023-08-11 11:37:22 -07:00
rfcomm Bluetooth: RFCOMM: Fix not validating setsockopt user input 2024-04-10 15:03:47 -04:00
6lowpan.c Bluetooth: constify the struct device_type usage 2024-03-06 17:24:07 -05:00
af_bluetooth.c Bluetooth: af_bluetooth: Fix deadlock 2024-03-06 17:26:25 -05:00
aosp.c Bluetooth: Fix null pointer deref on unexpected status event 2022-08-08 17:04:37 -07:00
aosp.h Bluetooth: aosp: Support AOSP Bluetooth Quality Report 2021-11-02 19:37:52 +01:00
coredump.c Bluetooth: Remove unnecessary NULL check before vfree() 2023-08-11 11:56:54 -07:00
ecdh_helper.c Bluetooth: Use crypto_wait_req 2023-02-13 18:34:48 +08:00
ecdh_helper.h Fix misc new gcc warnings 2021-04-27 17:05:53 -07:00
eir.c Bluetooth: Fix eir name length 2024-03-08 10:22:17 -05:00
eir.h Bluetooth: Add initial implementation of BIS connections 2022-07-22 17:13:56 -07:00
hci_codec.c Bluetooth: Fix support for Read Local Supported Codecs V2 2022-12-02 13:09:31 -08:00
hci_codec.h Bluetooth: Add support for Read Local Supported Codecs V2 2021-09-07 14:09:18 -07:00
hci_conn.c Bluetooth: hci_sync: Use advertised PHYs on hci_le_ext_create_conn_sync 2024-04-24 16:26:08 -04:00
hci_core.c Bluetooth: msft: fix slab-use-after-free in msft_do_close() 2024-05-03 13:05:28 -04:00
hci_debugfs.c Bluetooth: Fix TOCTOU in HCI debugfs implementation 2024-03-29 09:48:37 -04:00
hci_debugfs.h Bluetooth: hci_core: Move all debugfs handling to hci_debugfs.c 2021-09-22 16:17:13 +02:00
hci_event.c Bluetooth: HCI: Fix potential null-ptr-deref 2024-05-03 13:05:53 -04:00
hci_request.c Bluetooth: Fix memory leak in hci_req_sync_complete() 2024-04-10 15:03:44 -04:00
hci_request.h Bluetooth: Delete unused hci_req_prepare_suspend() declaration 2023-09-20 10:55:29 -07:00
hci_sock.c Bluetooth: hci_sock: Fix not validating setsockopt user input 2024-04-10 15:03:52 -04:00
hci_sync.c Bluetooth: hci_sync: Use advertised PHYs on hci_le_ext_create_conn_sync 2024-04-24 16:26:08 -04:00
hci_sysfs.c Bluetooth: Fix double free in hci_conn_cleanup 2023-10-23 11:05:11 -07:00
iso.c Bluetooth: ISO: Fix not validating setsockopt user input 2024-04-10 15:03:50 -04:00
Kconfig Bluetooth: Remove BT_HS 2024-03-06 17:22:39 -05:00
l2cap_core.c Bluetooth: l2cap: fix null-ptr-deref in l2cap_chan_timeout 2024-05-03 13:05:54 -04:00
l2cap_sock.c Bluetooth: Fix type of len in {l2cap,sco}_sock_getsockopt_old() 2024-04-24 16:26:06 -04:00
leds.c
leds.h
lib.c Bluetooth: Add documentation to exported functions in lib 2023-12-22 12:54:55 -05:00
Makefile Bluetooth: Remove BT_HS 2024-03-06 17:22:39 -05:00
mgmt_config.c Bluetooth: mgmt: Use the correct print format 2021-06-26 07:12:42 +02:00
mgmt_config.h
mgmt_util.c Bluetooth: Implement support for Mesh 2022-09-06 13:18:24 -07:00
mgmt_util.h Bluetooth: Fix a buffer overflow in mgmt_mesh_add() 2023-01-17 15:50:10 -08:00
mgmt.c Bluetooth: hci_sync: Using hci_cmd_sync_submit when removing Adv Monitor 2024-04-24 16:26:20 -04:00
msft.c Bluetooth: msft: fix slab-use-after-free in msft_do_close() 2024-05-03 13:05:28 -04:00
msft.h Bluetooth: msft: fix slab-use-after-free in msft_do_close() 2024-05-03 13:05:28 -04:00
sco.c Bluetooth: Fix use-after-free bugs caused by sco_sock_timeout 2024-05-03 13:03:53 -04:00
selftest.c crypto: ecdh - move curve_id of ECDH from the key to algorithm name 2021-03-13 00:04:03 +11:00
selftest.h
smp.c Bluetooth: MGMT/SMP: Fix address type when using SMP over BREDR/LE 2023-12-15 11:53:09 -05:00
smp.h Bluetooth: use inclusive language in SMP 2021-06-26 07:12:37 +02:00