{"id":"DEBIAN-CVE-2022-49909","details":"In the Linux kernel, the following vulnerability has been resolved:  Bluetooth: L2CAP: fix use-after-free in l2cap_conn_del()  When l2cap_recv_frame() is invoked to receive data, and the cid is L2CAP_CID_A2MP, if the channel does not exist, it will create a channel. However, after a channel is created, the hold operation of the channel is not performed. In this case, the value of channel reference counting is 1. As a result, after hci_error_reset() is triggered, l2cap_conn_del() invokes the close hook function of A2MP to release the channel. Then  l2cap_chan_unlock(chan) will trigger UAF issue.  The process is as follows: Receive data: l2cap_data_channel()     a2mp_channel_create()  ---\u003echannel ref is 2     l2cap_chan_put()       ---\u003echannel ref is 1  Triger event:     hci_error_reset()         hci_dev_do_close()         ...         l2cap_disconn_cfm()             l2cap_conn_del()                 l2cap_chan_hold()    ---\u003echannel ref is 2                 l2cap_chan_del()     ---\u003echannel ref is 1                 a2mp_chan_close_cb() ---\u003echannel ref is 0, release channel                 l2cap_chan_unlock()  ---\u003eUAF of channel  The detailed Call Trace is as follows: BUG: KASAN: use-after-free in __mutex_unlock_slowpath+0xa6/0x5e0 Read of size 8 at addr ffff8880160664b8 by task kworker/u11:1/7593 Workqueue: hci0 hci_error_reset Call Trace:  \u003cTASK\u003e  dump_stack_lvl+0xcd/0x134  print_report.cold+0x2ba/0x719  kasan_report+0xb1/0x1e0  kasan_check_range+0x140/0x190  __mutex_unlock_slowpath+0xa6/0x5e0  l2cap_conn_del+0x404/0x7b0  l2cap_disconn_cfm+0x8c/0xc0  hci_conn_hash_flush+0x11f/0x260  hci_dev_close_sync+0x5f5/0x11f0  hci_dev_do_close+0x2d/0x70  hci_error_reset+0x9e/0x140  process_one_work+0x98a/0x1620  worker_thread+0x665/0x1080  kthread+0x2e4/0x3a0  ret_from_fork+0x1f/0x30  \u003c/TASK\u003e  Allocated by task 7593:  kasan_save_stack+0x1e/0x40  __kasan_kmalloc+0xa9/0xd0  l2cap_chan_create+0x40/0x930  amp_mgr_create+0x96/0x990  a2mp_channel_create+0x7d/0x150  l2cap_recv_frame+0x51b8/0x9a70  l2cap_recv_acldata+0xaa3/0xc00  hci_rx_work+0x702/0x1220  process_one_work+0x98a/0x1620  worker_thread+0x665/0x1080  kthread+0x2e4/0x3a0  ret_from_fork+0x1f/0x30  Freed by task 7593:  kasan_save_stack+0x1e/0x40  kasan_set_track+0x21/0x30  kasan_set_free_info+0x20/0x30  ____kasan_slab_free+0x167/0x1c0  slab_free_freelist_hook+0x89/0x1c0  kfree+0xe2/0x580  l2cap_chan_put+0x22a/0x2d0  l2cap_conn_del+0x3fc/0x7b0  l2cap_disconn_cfm+0x8c/0xc0  hci_conn_hash_flush+0x11f/0x260  hci_dev_close_sync+0x5f5/0x11f0  hci_dev_do_close+0x2d/0x70  hci_error_reset+0x9e/0x140  process_one_work+0x98a/0x1620  worker_thread+0x665/0x1080  kthread+0x2e4/0x3a0  ret_from_fork+0x1f/0x30  Last potentially related work creation:  kasan_save_stack+0x1e/0x40  __kasan_record_aux_stack+0xbe/0xd0  call_rcu+0x99/0x740  netlink_release+0xe6a/0x1cf0  __sock_release+0xcd/0x280  sock_close+0x18/0x20  __fput+0x27c/0xa90  task_work_run+0xdd/0x1a0  exit_to_user_mode_prepare+0x23c/0x250  syscall_exit_to_user_mode+0x19/0x50  do_syscall_64+0x42/0x80  entry_SYSCALL_64_after_hwframe+0x63/0xcd  Second to last potentially related work creation:  kasan_save_stack+0x1e/0x40  __kasan_record_aux_stack+0xbe/0xd0  call_rcu+0x99/0x740  netlink_release+0xe6a/0x1cf0  __sock_release+0xcd/0x280  sock_close+0x18/0x20  __fput+0x27c/0xa90  task_work_run+0xdd/0x1a0  exit_to_user_mode_prepare+0x23c/0x250  syscall_exit_to_user_mode+0x19/0x50  do_syscall_64+0x42/0x80  entry_SYSCALL_64_after_hwframe+0x63/0xcd","modified":"2025-12-02T19:46:19.971275Z","published":"2025-05-01T15:16:16.030Z","withdrawn":"2025-12-02T19:46:19.971275Z","upstream":["CVE-2022-49909"],"references":[{"type":"ADVISORY","url":"https://security-tracker.debian.org/tracker/CVE-2022-49909"}],"affected":[{"package":{"name":"linux","ecosystem":"Debian:11","purl":"pkg:deb/debian/linux?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.10.158-1"}]}],"versions":["5.10.103-1","5.10.103-1~bpo10+1","5.10.106-1","5.10.113-1","5.10.120-1","5.10.120-1~bpo10+1","5.10.127-1","5.10.127-2","5.10.127-2~bpo10+1","5.10.136-1","5.10.140-1","5.10.148-1","5.10.149-1","5.10.149-2","5.10.46-4","5.10.46-5","5.10.70-1","5.10.70-1~bpo10+1","5.10.84-1","5.10.92-1","5.10.92-1~bpo10+1","5.10.92-2"],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49909.json"}},{"package":{"name":"linux","ecosystem":"Debian:12","purl":"pkg:deb/debian/linux?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.8-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49909.json"}},{"package":{"name":"linux","ecosystem":"Debian:13","purl":"pkg:deb/debian/linux?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.8-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49909.json"}},{"package":{"name":"linux","ecosystem":"Debian:14","purl":"pkg:deb/debian/linux?arch=source"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"6.0.8-1"}]}],"ecosystem_specific":{"urgency":"not yet assigned"},"database_specific":{"source":"https://storage.googleapis.com/osv-test-debian-osv/debian-cve-osv/DEBIAN-CVE-2022-49909.json"}}],"schema_version":"1.7.3","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}