kernel/linux.git/net/bluetooth, branch v5.15.209

Bluetooth: bnep: Fix UAF read of dev->name

2026-06-01T15:35:46+00:00

commit 59e932ded949fa6f0340bf7c6d7818f962fa4fd2 upstream. bnep_add_connection() needs to keep holding the bnep_session_sem while reading dev->name (just like bnep_get_connlist() does); otherwise the bnep_session() thread can concurrently free the net_device, which can for example be triggered by a concurrent bnep_del_connection(). (This UAF is fairly uninteresting from a security perspective; calling bnep_add_connection() requires passing a capable(CAP_NET_ADMIN) check. It also requires completely tearing down a netdev during a fairly tight race window.) Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jann Horn Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: l2cap: Add missing chan lock in l2cap_ecred_reconf_rsp

2026-06-01T15:35:29+00:00

[ Upstream commit 42776497cdbc9a665b384a6dcb85f0d4bd927eab ] l2cap_ecred_reconf_rsp() calls l2cap_chan_del() without holding l2cap_chan_lock(). Every other l2cap_chan_del() caller in the file acquires the lock first. A remote BLE device can send a crafted L2CAP ECRED reconfiguration response to corrupt the channel list while another thread is iterating it. Add l2cap_chan_hold() and l2cap_chan_lock() before l2cap_chan_del(), and l2cap_chan_unlock() and l2cap_chan_put() after, matching the pattern used in l2cap_ecred_conn_rsp() and l2cap_conn_del(). Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode") Signed-off-by: Dudu Lu Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: fix locking in hci_conn_request_evt() with HCI_PROTO_DEFER

2026-06-01T15:35:29+00:00

[ Upstream commit 5c7209a341ff2ac338b2b0375c34a307b37c9ac2 ] When protocol sets HCI_PROTO_DEFER, hci_conn_request_evt() calls hci_connect_cfm(conn) without hdev->lock. Generally hci_connect_cfm() assumes it is held, and if conn is deleted concurrently -> UAF. Only SCO and ISO set HCI_PROTO_DEFER and only for defer setup listen, and HCI_EV_CONN_REQUEST is not generated for ISO. In the non-deferred listening socket code paths, hci_connect_cfm(conn) is called with hdev->lock held. Fix by holding the lock. Fixes: 70c464256310 ("Bluetooth: Refactor connection request handling") Signed-off-by: Pauli Virtanen Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Sasha Levin

Bluetooth: L2CAP: Fix printing wrong information if SDU length exceeds MTU

2026-06-01T15:35:29+00:00

[ Upstream commit 15bf35a660eb82a49f8397fc3d3acada8dae13db ] The code was printing skb->len and sdu_len in the places where it should be sdu_len and chan->imtu respectively to match the if conditions. Link: https://lore.kernel.org/linux-bluetooth/20260315132013.75ab40c5@kernel.org/T/#m1418f9c82eeff8510c1beaa21cf53af20db96c06 Fixes: e1d9a6688986 ("Bluetooth: LE L2CAP: Disconnect if received packet's SDU exceeds IMTU") Signed-off-by: Luiz Augusto von Dentz Reviewed-by: Paul Menzel Signed-off-by: Sasha Levin

Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_get_sndtimeo_cb()

2026-06-01T15:35:26+00:00

commit 78a88d43dab8d23aeef934ed8ce34d40e6b3d613 upstream. Add the same NULL guard already present in l2cap_sock_resume_cb() and l2cap_sock_ready_cb(). Fixes: 8d836d71e222 ("Bluetooth: Access sk_sndtimeo indirectly in l2cap_core.c") Cc: stable@kernel.org Signed-off-by: Siwei Zhang Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_state_change_cb()

2026-06-01T15:35:21+00:00

commit 2ff1a41a912de8517b4482e946dd951b7d80edbf upstream. Add the same NULL guard already present in l2cap_sock_resume_cb() and l2cap_sock_ready_cb(). Fixes: 89bc500e41fc ("Bluetooth: Add state tracking to struct l2cap_chan") Cc: stable@kernel.org Signed-off-by: Siwei Zhang Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: L2CAP: Fix null-ptr-deref in l2cap_sock_new_connection_cb()

2026-06-01T15:35:21+00:00

commit 0a120d96166301d7a95be75b52f843837dbd1219 upstream. Add the same NULL guard already present in l2cap_sock_resume_cb() and l2cap_sock_ready_cb(). Fixes: 80808e431e1e ("Bluetooth: Add l2cap_chan_ops abstraction") Cc: stable@kernel.org Signed-off-by: Siwei Zhang Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Greg Kroah-Hartman

Bluetooth: af_bluetooth: Fix deadlock

2026-06-01T15:35:10+00:00

[ Upstream commit f7b94bdc1ec107c92262716b073b3e816d4784fb ] Attemting to do sock_lock on .recvmsg may cause a deadlock as shown bellow, so instead of using sock_sock this uses sk_receive_queue.lock on bt_sock_ioctl to avoid the UAF: INFO: task kworker/u9:1:121 blocked for more than 30 seconds. Not tainted 6.7.6-lemon #183 Workqueue: hci0 hci_rx_work Call Trace: __schedule+0x37d/0xa00 schedule+0x32/0xe0 __lock_sock+0x68/0xa0 ? __pfx_autoremove_wake_function+0x10/0x10 lock_sock_nested+0x43/0x50 l2cap_sock_recv_cb+0x21/0xa0 l2cap_recv_frame+0x55b/0x30a0 ? psi_task_switch+0xeb/0x270 ? finish_task_switch.isra.0+0x93/0x2a0 hci_rx_work+0x33a/0x3f0 process_one_work+0x13a/0x2f0 worker_thread+0x2f0/0x410 ? __pfx_worker_thread+0x10/0x10 kthread+0xe0/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1b/0x30 Fixes: 2e07e8348ea4 ("Bluetooth: af_bluetooth: Fix Use-After-Free in bt_sock_recvmsg") Signed-off-by: Luiz Augusto von Dentz [ The context change is due to the commit f4b41f062c42 ("net: remove noblock parameter from skb_recv_datagram()") in v5.19 which is irrelevant to the logic of this patch. ] Signed-off-by: Johnny Hao Signed-off-by: Greg Kroah-Hartman

Bluetooth: hci_core: Fix use-after-free in vhci_flush()

2026-06-01T15:35:09+00:00

[ Upstream commit 1d6123102e9fbedc8d25bf4731da6d513173e49e ] syzbot reported use-after-free in vhci_flush() without repro. [0] >From the splat, a thread close()d a vhci file descriptor while its device was being used by iotcl() on another thread. Once the last fd refcnt is released, vhci_release() calls hci_unregister_dev(), hci_free_dev(), and kfree() for struct vhci_data, which is set to hci_dev->dev->driver_data. The problem is that there is no synchronisation after unlinking hdev from hci_dev_list in hci_unregister_dev(). There might be another thread still accessing the hdev which was fetched before the unlink operation. We can use SRCU for such synchronisation. Let's run hci_dev_reset() under SRCU and wait for its completion in hci_unregister_dev(). Another option would be to restore hci_dev->destruct(), which was removed in commit 587ae086f6e4 ("Bluetooth: Remove unused hci-destruct cb"). However, this would not be a good solution, as we should not run hci_unregister_dev() while there are in-flight ioctl() requests, which could lead to another data-race KCSAN splat. Note that other drivers seem to have the same problem, for exmaple, virtbt_remove(). [0]: BUG: KASAN: slab-use-after-free in skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline] BUG: KASAN: slab-use-after-free in skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937 Read of size 8 at addr ffff88807cb8d858 by task syz.1.219/6718 CPU: 1 UID: 0 PID: 6718 Comm: syz.1.219 Not tainted 6.16.0-rc1-syzkaller-00196-g08207f42d3ff #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xd2/0x2b0 mm/kasan/report.c:521 kasan_report+0x118/0x150 mm/kasan/report.c:634 skb_queue_empty_lockless include/linux/skbuff.h:1891 [inline] skb_queue_purge_reason+0x99/0x360 net/core/skbuff.c:3937 skb_queue_purge include/linux/skbuff.h:3368 [inline] vhci_flush+0x44/0x50 drivers/bluetooth/hci_vhci.c:69 hci_dev_do_reset net/bluetooth/hci_core.c:552 [inline] hci_dev_reset+0x420/0x5c0 net/bluetooth/hci_core.c:592 sock_do_ioctl+0xd9/0x300 net/socket.c:1190 sock_ioctl+0x576/0x790 net/socket.c:1311 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fcf5b98e929 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fcf5c7b9038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fcf5bbb6160 RCX: 00007fcf5b98e929 RDX: 0000000000000000 RSI: 00000000400448cb RDI: 0000000000000009 RBP: 00007fcf5ba10b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fcf5bbb6160 R15: 00007ffd6353d528 Allocated by task 6535: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x230/0x3d0 mm/slub.c:4359 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] vhci_open+0x57/0x360 drivers/bluetooth/hci_vhci.c:635 misc_open+0x2bc/0x330 drivers/char/misc.c:161 chrdev_open+0x4c9/0x5e0 fs/char_dev.c:414 do_dentry_open+0xdf0/0x1970 fs/open.c:964 vfs_open+0x3b/0x340 fs/open.c:1094 do_open fs/namei.c:3887 [inline] path_openat+0x2ee5/0x3830 fs/namei.c:4046 do_filp_open+0x1fa/0x410 fs/namei.c:4073 do_sys_openat2+0x121/0x1c0 fs/open.c:1437 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 6535: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x62/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2381 [inline] slab_free mm/slub.c:4643 [inline] kfree+0x18e/0x440 mm/slub.c:4842 vhci_release+0xbc/0xd0 drivers/bluetooth/hci_vhci.c:671 __fput+0x44c/0xa70 fs/file_table.c:465 task_work_run+0x1d1/0x260 kernel/task_work.c:227 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x6ad/0x22e0 kernel/exit.c:955 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104 __do_sys_exit_group kernel/exit.c:1115 [inline] __se_sys_exit_group kernel/exit.c:1113 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1113 x64_sys_call+0x21ba/0x21c0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88807cb8d800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 88 bytes inside of freed 1024-byte region [ffff88807cb8d800, ffff88807cb8dc00) Fixes: bf18c7118cf8 ("Bluetooth: vhci: Free driver_data on file release") Reported-by: syzbot+2faa4825e556199361f9@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=f62d64848fc4c7c30cd6 Signed-off-by: Kuniyuki Iwashima Acked-by: Paul Menzel Signed-off-by: Luiz Augusto von Dentz [ Minor context conflict resolved. ] Signed-off-by: Ruohan Lan Signed-off-by: Greg Kroah-Hartman

Bluetooth: L2CAP: Fix accepting multiple L2CAP_ECRED_CONN_REQ

2026-04-18T08:33:39+00:00

[ Upstream commit 5b3e2052334f2ff6d5200e952f4aa66994d09899 ] Currently the code attempts to accept requests regardless of the command identifier which may cause multiple requests to be marked as pending (FLAG_DEFER_SETUP) which can cause more than L2CAP_ECRED_MAX_CID(5) to be allocated in l2cap_ecred_rsp_defer causing an overflow. The spec is quite clear that the same identifier shall not be used on subsequent requests: 'Within each signaling channel a different Identifier shall be used for each successive request or indication.' https://www.bluetooth.com/wp-content/uploads/Files/Specification/HTML/Core-62/out/en/host/logical-link-control-and-adaptation-protocol-specification.html#UUID-32a25a06-4aa4-c6c7-77c5-dcfe3682355d So this attempts to check if there are any channels pending with the same identifier and rejects if any are found. Fixes: 15f02b910562 ("Bluetooth: L2CAP: Add initial code for Enhanced Credit Based Mode") Reported-by: Yiming Qian Signed-off-by: Luiz Augusto von Dentz [ adapted variable names ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman