kernel/linux.git/include/net/bluetooth/l2cap.h, branch v6.6.131

Bluetooth: L2CAP: Fix invalid response to L2CAP_ECRED_RECONF_REQ

2026-03-04T12:21:00+00:00

[ Upstream commit 7accb1c4321acb617faf934af59d928b0b047e2b ] This fixes responding with an invalid result caused by checking the wrong size of CID which should have been (cmd_len - sizeof(*req)) and on top of it the wrong result was use L2CAP_CR_LE_INVALID_PARAMS which is invalid/reserved for reconf when running test like L2CAP/ECFC/BI-03-C: > ACL Data RX: Handle 64 flags 0x02 dlen 14 LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 2 len 6 MTU: 64 MPS: 64 Source CID: 64 < ACL Data TX: Handle 64 flags 0x00 dlen 10 LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2 ! Result: Reserved (0x000c) Result: Reconfiguration failed - one or more Destination CIDs invalid (0x0003) Fiix L2CAP/ECFC/BI-04-C which expects L2CAP_RECONF_INVALID_MPS (0x0002) when more than one channel gets its MPS reduced: > ACL Data RX: Handle 64 flags 0x02 dlen 16 LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 2 len 8 MTU: 264 MPS: 99 Source CID: 64 ! Source CID: 65 < ACL Data TX: Handle 64 flags 0x00 dlen 10 LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2 ! Result: Reconfiguration successful (0x0000) Result: Reconfiguration failed - reduction in size of MPS not allowed for more than one channel at a time (0x0002) Fix L2CAP/ECFC/BI-05-C when SCID is invalid (85 unconnected): > ACL Data RX: Handle 64 flags 0x02 dlen 14 LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 2 len 6 MTU: 65 MPS: 64 ! Source CID: 85 < ACL Data TX: Handle 64 flags 0x00 dlen 10 LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2 ! Result: Reconfiguration successful (0x0000) Result: Reconfiguration failed - one or more Destination CIDs invalid (0x0003) Fix L2CAP/ECFC/BI-06-C when MPS < L2CAP_ECRED_MIN_MPS (64): > ACL Data RX: Handle 64 flags 0x02 dlen 14 LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 2 len 6 MTU: 672 ! MPS: 63 Source CID: 64 < ACL Data TX: Handle 64 flags 0x00 dlen 10 LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2 ! Result: Reconfiguration failed - reduction in size of MPS not allowed for more than one channel at a time (0x0002) Result: Reconfiguration failed - other unacceptable parameters (0x0004) Fix L2CAP/ECFC/BI-07-C when MPS reduced for more than one channel: > ACL Data RX: Handle 64 flags 0x02 dlen 16 LE L2CAP: Enhanced Credit Reconfigure Request (0x19) ident 3 len 8 MTU: 84 ! MPS: 71 Source CID: 64 ! Source CID: 65 < ACL Data TX: Handle 64 flags 0x00 dlen 10 LE L2CAP: Enhanced Credit Reconfigure Respond (0x1a) ident 2 len 2 ! Result: Reconfiguration successful (0x0000) Result: Reconfiguration failed - reduction in size of MPS not allowed for more than one channel at a time (0x0002) Link: https://github.com/bluez/bluez/issues/1865 Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode") Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: L2CAP: Fix corrupted list in hci_chan_del

2025-03-22T19:50:50+00:00

commit ab4eedb790cae44313759b50fe47da285e2519d5 upstream. This fixes the following trace by reworking the locking of l2cap_conn so instead of only locking when changing the chan_l list this promotes chan_lock to a general lock of l2cap_conn so whenever it is being held it would prevents the likes of l2cap_conn_del to run: list_del corruption, ffff888021297e00->prev is LIST_POISON2 (dead000000000122) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:61! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 UID: 0 PID: 5896 Comm: syz-executor213 Not tainted 6.14.0-rc1-next-20250204-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__list_del_entry_valid_or_report+0x12c/0x190 lib/list_debug.c:59 Code: 8c 4c 89 fe 48 89 da e8 32 8c 37 fc 90 0f 0b 48 89 df e8 27 9f 14 fd 48 c7 c7 a0 c0 60 8c 4c 89 fe 48 89 da e8 15 8c 37 fc 90 <0f> 0b 4c 89 e7 e8 0a 9f 14 fd 42 80 3c 2b 00 74 08 4c 89 e7 e8 cb RSP: 0018:ffffc90003f6f998 EFLAGS: 00010246 RAX: 000000000000004e RBX: dead000000000122 RCX: 01454d423f7fbf00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff819f077c R09: 1ffff920007eded0 R10: dffffc0000000000 R11: fffff520007eded1 R12: dead000000000122 R13: dffffc0000000000 R14: ffff8880352248d8 R15: ffff888021297e00 FS: 00007f7ace6686c0(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7aceeeb1d0 CR3: 000000003527c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __list_del_entry_valid include/linux/list.h:124 [inline] __list_del_entry include/linux/list.h:215 [inline] list_del_rcu include/linux/rculist.h:168 [inline] hci_chan_del+0x70/0x1b0 net/bluetooth/hci_conn.c:2858 l2cap_conn_free net/bluetooth/l2cap_core.c:1816 [inline] kref_put include/linux/kref.h:65 [inline] l2cap_conn_put+0x70/0xe0 net/bluetooth/l2cap_core.c:1830 l2cap_sock_shutdown+0xa8a/0x1020 net/bluetooth/l2cap_sock.c:1377 l2cap_sock_release+0x79/0x1d0 net/bluetooth/l2cap_sock.c:1416 __sock_release net/socket.c:642 [inline] sock_close+0xbc/0x240 net/socket.c:1393 __fput+0x3e9/0x9f0 fs/file_table.c:448 task_work_run+0x24f/0x310 kernel/task_work.c:227 ptrace_notify+0x2d2/0x380 kernel/signal.c:2522 ptrace_report_syscall include/linux/ptrace.h:415 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:477 [inline] syscall_exit_work+0xc7/0x1d0 kernel/entry/common.c:173 syscall_exit_to_user_mode_prepare kernel/entry/common.c:200 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:205 [inline] syscall_exit_to_user_mode+0x24a/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7aceeaf449 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 19 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f7ace668218 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: fffffffffffffffc RBX: 00007f7acef39328 RCX: 00007f7aceeaf449 RDX: 000000000000000e RSI: 0000000020000100 RDI: 0000000000000004 RBP: 00007f7acef39320 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000004 R14: 00007f7ace668670 R15: 000000000000000b Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__list_del_entry_valid_or_report+0x12c/0x190 lib/list_debug.c:59 Code: 8c 4c 89 fe 48 89 da e8 32 8c 37 fc 90 0f 0b 48 89 df e8 27 9f 14 fd 48 c7 c7 a0 c0 60 8c 4c 89 fe 48 89 da e8 15 8c 37 fc 90 <0f> 0b 4c 89 e7 e8 0a 9f 14 fd 42 80 3c 2b 00 74 08 4c 89 e7 e8 cb RSP: 0018:ffffc90003f6f998 EFLAGS: 00010246 RAX: 000000000000004e RBX: dead000000000122 RCX: 01454d423f7fbf00 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: dffffc0000000000 R08: ffffffff819f077c R09: 1ffff920007eded0 R10: dffffc0000000000 R11: fffff520007eded1 R12: dead000000000122 R13: dffffc0000000000 R14: ffff8880352248d8 R15: ffff888021297e00 FS: 00007f7ace6686c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7acef05b08 CR3: 000000003527c000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Reported-by: syzbot+10bd8fe6741eedd2be2e@syzkaller.appspotmail.com Tested-by: syzbot+10bd8fe6741eedd2be2e@syzkaller.appspotmail.com Fixes: b4f82f9ed43a ("Bluetooth: L2CAP: Fix slab-use-after-free Read in l2cap_send_cmd") Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Dan Carpenter Signed-off-by: Greg Kroah-Hartman

Bluetooth: compute LE flow credits based on recvbuf space

2024-06-12T09:11:55+00:00

[ Upstream commit ce60b9231b66710b6ee24042ded26efee120ecfc ] Previously LE flow credits were returned to the sender even if the socket's receive buffer was full. This meant that no back-pressure was applied to the sender, thus it continued to send data, resulting in data loss without any error being reported. Furthermore, the amount of credits was essentially fixed to a small amount, leading to reduced performance. This is fixed by computing the number of returned LE flow credits based on the estimated available space in the receive buffer of an L2CAP socket. Consequently, if the receive buffer is full, no credits are returned until the buffer is read and thus cleared by user-space. Since the computation of available receive buffer space can only be performed approximately (due to sk_buff overhead) and the receive buffer size may be changed by user-space after flow credits have been sent, superfluous received data is temporary stored within l2cap_pinfo. This is necessary because Bluetooth LE provides no retransmission mechanism once the data has been acked by the physical layer. If receive buffer space estimation is not possible at the moment, we fall back to providing credits for one full packet as before. This is currently the case during connection setup, when MPS is not yet available. Fixes: b1c325c23d75 ("Bluetooth: Implement returning of LE L2CAP credits") Signed-off-by: Sebastian Urban Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: Remove BT_HS

2024-03-26T22:19:37+00:00

[ Upstream commit e7b02296fb400ee64822fbdd81a0718449066333 ] High Speed, Alternate MAC and PHY (AMP) extension, has been removed from Bluetooth Core specification on 5.3: https://www.bluetooth.com/blog/new-core-specification-v5-3-feature-enhancements/ Fixes: 244bc377591c ("Bluetooth: Add BT_HS config option") Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: L2CAP: Delay identity address updates

2023-04-24T04:48:44+00:00

This delays the identity address updates to give time for userspace to process the new address otherwise there is a risk that userspace creates a duplicated device if the MGMT event is delayed for some reason. Signed-off-by: Luiz Augusto von Dentz

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

2022-07-26T20:35:24+00:00

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

Bluetooth: L2CAP: Fix not checking for maximum number of DCID

2021-03-15T20:08:33+00:00

When receiving L2CAP_CREDIT_BASED_CONNECTION_REQ the remote may request more channels than allowed by the spec (10 octecs = 5 CIDs) so this checks if the number of channels is bigger than the maximum allowed and respond with an error. Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Marcel Holtmann

Bluetooth: L2CAP: Fix handling fragmented length

2021-01-25T18:26:33+00:00

Bluetooth Core Specification v5.2, Vol. 3, Part A, section 1.4, table 1.1: 'Start Fragments always either begin with the first octet of the Basic L2CAP header of a PDU or they have a length of zero (see [Vol 2] Part B, Section 6.6.2).' Apparently this was changed by the following errata: https://www.bluetooth.org/tse/errata_view.cfm?errata_id=10216 Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Marcel Holtmann

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

2020-09-25T18:21:55+00:00

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

Bluetooth: L2CAP: Replace zero-length array with flexible-array

2020-05-18T07:57:41+00:00

The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva Signed-off-by: Marcel Holtmann