kernel/linux.git/net/bluetooth/l2cap_core.c, branch v4.9.331

Bluetooth: L2CAP: Fix user-after-free

2022-10-26T11:15:46+00:00

[ Upstream commit 35fcbc4243aad7e7d020b7c1dfb14bb888b20a4f ] This uses l2cap_chan_hold_unless_zero() after calling __l2cap_get_chan_blah() to prevent the following trace: Bluetooth: l2cap_core.c:static void l2cap_chan_destroy(struct kref *kref) Bluetooth: chan 0000000023c4974d Bluetooth: parent 00000000ae861c08 ================================================================== BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:671 [inline] BUG: KASAN: use-after-free in __mutex_lock+0x278/0x400 kernel/locking/mutex.c:729 Read of size 8 at addr ffff888006a49b08 by task kworker/u3:2/389 Link: https://lore.kernel.org/lkml/20220622082716.478486-1-lee.jones@linaro.org Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sungwoo Kim Signed-off-by: Sasha Levin

Bluetooth: L2CAP: initialize delayed works at l2cap_chan_create()

2022-10-26T11:15:45+00:00

[ Upstream commit 2d2cb3066f2c90cd8ca540b36ba7a55e7f2406e0 ] syzbot is reporting cancel_delayed_work() without INIT_DELAYED_WORK() at l2cap_chan_del() [1], for CONF_NOT_COMPLETE flag (which meant to prevent l2cap_chan_del() from calling cancel_delayed_work()) is cleared by timer which fires before l2cap_chan_del() is called by closing file descriptor created by socket(AF_BLUETOOTH, SOCK_STREAM, BTPROTO_L2CAP). l2cap_bredr_sig_cmd(L2CAP_CONF_REQ) and l2cap_bredr_sig_cmd(L2CAP_CONF_RSP) are calling l2cap_ertm_init(chan), and they call l2cap_chan_ready() (which clears CONF_NOT_COMPLETE flag) only when l2cap_ertm_init(chan) succeeded. l2cap_sock_init() does not call l2cap_ertm_init(chan), and it instead sets CONF_NOT_COMPLETE flag by calling l2cap_chan_set_defaults(). However, when connect() is requested, "command 0x0409 tx timeout" happens after 2 seconds from connect() request, and CONF_NOT_COMPLETE flag is cleared after 4 seconds from connect() request, for l2cap_conn_start() from l2cap_info_timeout() callback scheduled by schedule_delayed_work(&conn->info_timer, L2CAP_INFO_TIMEOUT); in l2cap_connect() is calling l2cap_chan_ready(). Fix this problem by initializing delayed works used by L2CAP_MODE_ERTM mode as soon as l2cap_chan_create() allocates a channel, like I did in commit be8597239379f0f5 ("Bluetooth: initialize skb_queue_head at l2cap_chan_create()"). Link: https://syzkaller.appspot.com/bug?extid=83672956c7aa6af698b3 [1] Reported-by: syzbot Signed-off-by: Tetsuo Handa Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: L2CAP: Fix build errors in some archs

2022-09-05T08:23:57+00:00

commit b840304fb46cdf7012722f456bce06f151b3e81b upstream. This attempts to fix the follow errors: In function 'memcmp', inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9, inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2003:15: ./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread] 44 | #define __underlying_memcmp __builtin_memcmp | ^ ./include/linux/fortify-string.h:420:16: note: in expansion of macro '__underlying_memcmp' 420 | return __underlying_memcmp(p, q, size); | ^~~~~~~~~~~~~~~~~~~ In function 'memcmp', inlined from 'bacmp' at ./include/net/bluetooth/bluetooth.h:347:9, inlined from 'l2cap_global_chan_by_psm' at net/bluetooth/l2cap_core.c:2004:15: ./include/linux/fortify-string.h:44:33: error: '__builtin_memcmp' specified bound 6 exceeds source size 0 [-Werror=stringop-overread] 44 | #define __underlying_memcmp __builtin_memcmp | ^ ./include/linux/fortify-string.h:420:16: note: in expansion of macro '__underlying_memcmp' 420 | return __underlying_memcmp(p, q, size); | ^~~~~~~~~~~~~~~~~~~ Fixes: 332f1795ca20 ("Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression") Signed-off-by: Luiz Augusto von Dentz Cc: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman

Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression

2022-08-25T09:09:27+00:00

commit 332f1795ca202489c665a75e62e18ff6284de077 upstream. The patch d0be8347c623: "Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put" from Jul 21, 2022, leads to the following Smatch static checker warning: net/bluetooth/l2cap_core.c:1977 l2cap_global_chan_by_psm() error: we previously assumed 'c' could be null (see line 1996) Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put") Reported-by: Dan Carpenter Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put

2022-08-25T09:09:20+00:00

commit d0be8347c623e0ac4202a1d4e0373882821f56b0 upstream. This fixes the following trace which is caused by hci_rx_work starting up *after* the final channel reference has been put() during sock_close() but *before* the references to the channel have been destroyed, so instead the code now rely on kref_get_unless_zero/l2cap_chan_hold_unless_zero to prevent referencing a channel that is about to be destroyed. refcount_t: increment on 0; use-after-free. BUG: KASAN: use-after-free in refcount_dec_and_test+0x20/0xd0 Read of size 4 at addr ffffffc114f5bf18 by task kworker/u17:14/705 CPU: 4 PID: 705 Comm: kworker/u17:14 Tainted: G S W 4.14.234-00003-g1fb6d0bd49a4-dirty #28 Hardware name: Qualcomm Technologies, Inc. SM8150 V2 PM8150 Google Inc. MSM sm8150 Flame DVT (DT) Workqueue: hci0 hci_rx_work Call trace: dump_backtrace+0x0/0x378 show_stack+0x20/0x2c dump_stack+0x124/0x148 print_address_description+0x80/0x2e8 __kasan_report+0x168/0x188 kasan_report+0x10/0x18 __asan_load4+0x84/0x8c refcount_dec_and_test+0x20/0xd0 l2cap_chan_put+0x48/0x12c l2cap_recv_frame+0x4770/0x6550 l2cap_recv_acldata+0x44c/0x7a4 hci_acldata_packet+0x100/0x188 hci_rx_work+0x178/0x23c process_one_work+0x35c/0x95c worker_thread+0x4cc/0x960 kthread+0x1a8/0x1c4 ret_from_fork+0x10/0x18 Cc: stable@kernel.org Reported-by: Lee Jones Signed-off-by: Luiz Augusto von Dentz Tested-by: Lee Jones Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: initialize skb_queue_head at l2cap_chan_create()

2021-05-22T08:40:29+00:00

[ Upstream commit be8597239379f0f53c9710dd6ab551bbf535bec6 ] syzbot is hitting "INFO: trying to register non-static key." message [1], for "struct l2cap_chan"->tx_q.lock spinlock is not yet initialized when l2cap_chan_del() is called due to e.g. timeout. Since "struct l2cap_chan"->lock mutex is initialized at l2cap_chan_create() immediately after "struct l2cap_chan" is allocated using kzalloc(), let's as well initialize "struct l2cap_chan"->{tx_q,srej_q}.lock spinlocks there. [1] https://syzkaller.appspot.com/bug?extid=fadfba6a911f6bf71842 Reported-and-tested-by: syzbot Signed-off-by: Tetsuo Handa Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin

Bluetooth: Set CONF_NOT_COMPLETE as l2cap_chan default

2021-05-22T08:40:29+00:00

[ Upstream commit 3a9d54b1947ecea8eea9a902c0b7eb58a98add8a ] Currently l2cap_chan_set_defaults() reset chan->conf_state to zero. However, there is a flag CONF_NOT_COMPLETE which is set when creating the l2cap_chan. It is suggested that the flag should be cleared when l2cap_chan is ready, but when l2cap_chan_set_defaults() is called, l2cap_chan is not yet ready. Therefore, we must set this flag as the default. Example crash call trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0xc4/0x118 lib/dump_stack.c:56 panic+0x1c6/0x38b kernel/panic.c:117 __warn+0x170/0x1b9 kernel/panic.c:471 warn_slowpath_fmt+0xc7/0xf8 kernel/panic.c:494 debug_print_object+0x175/0x193 lib/debugobjects.c:260 debug_object_assert_init+0x171/0x1bf lib/debugobjects.c:614 debug_timer_assert_init kernel/time/timer.c:629 [inline] debug_assert_init kernel/time/timer.c:677 [inline] del_timer+0x7c/0x179 kernel/time/timer.c:1034 try_to_grab_pending+0x81/0x2e5 kernel/workqueue.c:1230 cancel_delayed_work+0x7c/0x1c4 kernel/workqueue.c:2929 l2cap_clear_timer+0x1e/0x41 include/net/bluetooth/l2cap.h:834 l2cap_chan_del+0x2d8/0x37e net/bluetooth/l2cap_core.c:640 l2cap_chan_close+0x532/0x5d8 net/bluetooth/l2cap_core.c:756 l2cap_sock_shutdown+0x806/0x969 net/bluetooth/l2cap_sock.c:1174 l2cap_sock_release+0x64/0x14d net/bluetooth/l2cap_sock.c:1217 __sock_release+0xda/0x217 net/socket.c:580 sock_close+0x1b/0x1f net/socket.c:1039 __fput+0x322/0x55c fs/file_table.c:208 ____fput+0x17/0x19 fs/file_table.c:244 task_work_run+0x19b/0x1d3 kernel/task_work.c:115 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0xe4c/0x204a kernel/exit.c:766 do_group_exit+0x291/0x291 kernel/exit.c:891 get_signal+0x749/0x1093 kernel/signal.c:2396 do_signal+0xa5/0xcdb arch/x86/kernel/signal.c:737 exit_to_usermode_loop arch/x86/entry/common.c:243 [inline] prepare_exit_to_usermode+0xed/0x235 arch/x86/entry/common.c:277 syscall_return_slowpath+0x3a7/0x3b3 arch/x86/entry/common.c:348 int_ret_from_sys_call+0x25/0xa3 Signed-off-by: Archie Pusaka Reported-by: syzbot+338f014a98367a08a114@syzkaller.appspotmail.com Reviewed-by: Alain Michaud Reviewed-by: Abhishek Pandit-Subedi Reviewed-by: Guenter Roeck Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin

Bluetooth: L2CAP: Fix calling sk_filter on non-socket based channel

2020-10-17T09:02:19+00:00

commit f19425641cb2572a33cb074d5e30283720bd4d22 upstream. Only sockets will have the chan->data set to an actual sk, channels like A2MP would have its own data which would likely cause a crash when calling sk_filter, in order to fix this a new callback has been introduced so channels can implement their own filtering if necessary. Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Marcel Holtmann Signed-off-by: Greg Kroah-Hartman

Bluetooth: L2CAP: handle l2cap config request during open state

2020-10-01T18:40:09+00:00

[ Upstream commit 96298f640104e4cd9a913a6e50b0b981829b94ff ] According to Core Spec Version 5.2 | Vol 3, Part A 6.1.5, the incoming L2CAP_ConfigReq should be handled during OPEN state. The section below shows the btmon trace when running L2CAP/COS/CFD/BV-12-C before and after this change. === Before === ... > ACL Data RX: Handle 256 flags 0x02 dlen 12 #22 L2CAP: Connection Request (0x02) ident 2 len 4 PSM: 1 (0x0001) Source CID: 65 < ACL Data TX: Handle 256 flags 0x00 dlen 16 #23 L2CAP: Connection Response (0x03) ident 2 len 8 Destination CID: 64 Source CID: 65 Result: Connection successful (0x0000) Status: No further information available (0x0000) < ACL Data TX: Handle 256 flags 0x00 dlen 12 #24 L2CAP: Configure Request (0x04) ident 2 len 4 Destination CID: 65 Flags: 0x0000 > HCI Event: Number of Completed Packets (0x13) plen 5 #25 Num handles: 1 Handle: 256 Count: 1 > HCI Event: Number of Completed Packets (0x13) plen 5 #26 Num handles: 1 Handle: 256 Count: 1 > ACL Data RX: Handle 256 flags 0x02 dlen 16 #27 L2CAP: Configure Request (0x04) ident 3 len 8 Destination CID: 64 Flags: 0x0000 Option: Unknown (0x10) [hint] 01 00 .. < ACL Data TX: Handle 256 flags 0x00 dlen 18 #28 L2CAP: Configure Response (0x05) ident 3 len 10 Source CID: 65 Flags: 0x0000 Result: Success (0x0000) Option: Maximum Transmission Unit (0x01) [mandatory] MTU: 672 > HCI Event: Number of Completed Packets (0x13) plen 5 #29 Num handles: 1 Handle: 256 Count: 1 > ACL Data RX: Handle 256 flags 0x02 dlen 14 #30 L2CAP: Configure Response (0x05) ident 2 len 6 Source CID: 64 Flags: 0x0000 Result: Success (0x0000) > ACL Data RX: Handle 256 flags 0x02 dlen 20 #31 L2CAP: Configure Request (0x04) ident 3 len 12 Destination CID: 64 Flags: 0x0000 Option: Unknown (0x10) [hint] 01 00 91 02 11 11 ...... < ACL Data TX: Handle 256 flags 0x00 dlen 14 #32 L2CAP: Command Reject (0x01) ident 3 len 6 Reason: Invalid CID in request (0x0002) Destination CID: 64 Source CID: 65 > HCI Event: Number of Completed Packets (0x13) plen 5 #33 Num handles: 1 Handle: 256 Count: 1 ... === After === ... > ACL Data RX: Handle 256 flags 0x02 dlen 12 #22 L2CAP: Connection Request (0x02) ident 2 len 4 PSM: 1 (0x0001) Source CID: 65 < ACL Data TX: Handle 256 flags 0x00 dlen 16 #23 L2CAP: Connection Response (0x03) ident 2 len 8 Destination CID: 64 Source CID: 65 Result: Connection successful (0x0000) Status: No further information available (0x0000) < ACL Data TX: Handle 256 flags 0x00 dlen 12 #24 L2CAP: Configure Request (0x04) ident 2 len 4 Destination CID: 65 Flags: 0x0000 > HCI Event: Number of Completed Packets (0x13) plen 5 #25 Num handles: 1 Handle: 256 Count: 1 > HCI Event: Number of Completed Packets (0x13) plen 5 #26 Num handles: 1 Handle: 256 Count: 1 > ACL Data RX: Handle 256 flags 0x02 dlen 16 #27 L2CAP: Configure Request (0x04) ident 3 len 8 Destination CID: 64 Flags: 0x0000 Option: Unknown (0x10) [hint] 01 00 .. < ACL Data TX: Handle 256 flags 0x00 dlen 18 #28 L2CAP: Configure Response (0x05) ident 3 len 10 Source CID: 65 Flags: 0x0000 Result: Success (0x0000) Option: Maximum Transmission Unit (0x01) [mandatory] MTU: 672 > HCI Event: Number of Completed Packets (0x13) plen 5 #29 Num handles: 1 Handle: 256 Count: 1 > ACL Data RX: Handle 256 flags 0x02 dlen 14 #30 L2CAP: Configure Response (0x05) ident 2 len 6 Source CID: 64 Flags: 0x0000 Result: Success (0x0000) > ACL Data RX: Handle 256 flags 0x02 dlen 20 #31 L2CAP: Configure Request (0x04) ident 3 len 12 Destination CID: 64 Flags: 0x0000 Option: Unknown (0x10) [hint] 01 00 91 02 11 11 ..... < ACL Data TX: Handle 256 flags 0x00 dlen 18 #32 L2CAP: Configure Response (0x05) ident 3 len 10 Source CID: 65 Flags: 0x0000 Result: Success (0x0000) Option: Maximum Transmission Unit (0x01) [mandatory] MTU: 672 < ACL Data TX: Handle 256 flags 0x00 dlen 12 #33 L2CAP: Configure Request (0x04) ident 3 len 4 Destination CID: 65 Flags: 0x0000 > HCI Event: Number of Completed Packets (0x13) plen 5 #34 Num handles: 1 Handle: 256 Count: 1 > HCI Event: Number of Completed Packets (0x13) plen 5 #35 Num handles: 1 Handle: 256 Count: 1 ... Signed-off-by: Howard Chung Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin

Bluetooth: Fix refcount use-after-free issue

2020-10-01T18:40:05+00:00

[ Upstream commit 6c08fc896b60893c5d673764b0668015d76df462 ] There is no lock preventing both l2cap_sock_release() and chan->ops->close() from running at the same time. If we consider Thread A running l2cap_chan_timeout() and Thread B running l2cap_sock_release(), expected behavior is: A::l2cap_chan_timeout()->l2cap_chan_close()->l2cap_sock_teardown_cb() A::l2cap_chan_timeout()->l2cap_sock_close_cb()->l2cap_sock_kill() B::l2cap_sock_release()->sock_orphan() B::l2cap_sock_release()->l2cap_sock_kill() where, sock_orphan() clears "sk->sk_socket" and l2cap_sock_teardown_cb() marks socket as SOCK_ZAPPED. In l2cap_sock_kill(), there is an "if-statement" that checks if both sock_orphan() and sock_teardown() has been run i.e. sk->sk_socket is NULL and socket is marked as SOCK_ZAPPED. Socket is killed if the condition is satisfied. In the race condition, following occurs: A::l2cap_chan_timeout()->l2cap_chan_close()->l2cap_sock_teardown_cb() B::l2cap_sock_release()->sock_orphan() B::l2cap_sock_release()->l2cap_sock_kill() A::l2cap_chan_timeout()->l2cap_sock_close_cb()->l2cap_sock_kill() In this scenario, "if-statement" is true in both B::l2cap_sock_kill() and A::l2cap_sock_kill() and we hit "refcount: underflow; use-after-free" bug. Similar condition occurs at other places where teardown/sock_kill is happening: l2cap_disconnect_rsp()->l2cap_chan_del()->l2cap_sock_teardown_cb() l2cap_disconnect_rsp()->l2cap_sock_close_cb()->l2cap_sock_kill() l2cap_conn_del()->l2cap_chan_del()->l2cap_sock_teardown_cb() l2cap_conn_del()->l2cap_sock_close_cb()->l2cap_sock_kill() l2cap_disconnect_req()->l2cap_chan_del()->l2cap_sock_teardown_cb() l2cap_disconnect_req()->l2cap_sock_close_cb()->l2cap_sock_kill() l2cap_sock_cleanup_listen()->l2cap_chan_close()->l2cap_sock_teardown_cb() l2cap_sock_cleanup_listen()->l2cap_sock_kill() Protect teardown/sock_kill and orphan/sock_kill by adding hold_lock on l2cap channel to ensure that the socket is killed only after marked as zapped and orphan. Signed-off-by: Manish Mandlik Signed-off-by: Marcel Holtmann Signed-off-by: Sasha Levin