ghsa-3vg9-6vwr-fh6q
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu
Fix the race condition between the following two flows that run in parallel:
-
l2cap_reassemble_sdu -> chan->ops->recv (l2cap_sock_recv_cb) -> __sock_queue_rcv_skb.
-
bt_sock_recvmsg -> skb_recv_datagram, skb_free_datagram.
An SKB can be queued by the first flow and immediately dequeued and freed by the second flow, therefore the callers of l2cap_reassemble_sdu can't use the SKB after that function returns. However, some places continue accessing struct l2cap_ctrl that resides in the SKB's CB for a short time after l2cap_reassemble_sdu returns, leading to a use-after-free condition (the stack trace is below, line numbers for kernel 5.19.8).
Fix it by keeping a local copy of struct l2cap_ctrl.
BUG: KASAN: use-after-free in l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth Read of size 1 at addr ffff88812025f2f0 by task kworker/u17:3/43169
Workqueue: hci0 hci_rx_work [bluetooth]
Call Trace:
Allocated by task 43169: kasan_save_stack (mm/kasan/common.c:39) __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469) kmem_cache_alloc_node (mm/slab.h:750 mm/slub.c:3243 mm/slub.c:3293) __alloc_skb (net/core/skbuff.c:414) l2cap_recv_frag (./include/net/bluetooth/bluetooth.h:425 net/bluetooth/l2cap_core.c:8329) bluetooth l2cap_recv_acldata (net/bluetooth/l2cap_core.c:8442) bluetooth hci_rx_work (net/bluetooth/hci_core.c:3642 net/bluetooth/hci_core.c:3832) bluetooth process_one_work (kernel/workqueue.c:2289) worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2437) kthread (kernel/kthread.c:376) ret_from_fork (arch/x86/entry/entry_64.S:306)
Freed by task 27920: kasan_save_stack (mm/kasan/common.c:39) kasan_set_track (mm/kasan/common.c:45) kasan_set_free_info (mm/kasan/generic.c:372) ____kasan_slab_free (mm/kasan/common.c:368 mm/kasan/common.c:328) slab_free_freelist_hook (mm/slub.c:1780) kmem_cache_free (mm/slub.c:3536 mm/slub.c:3553) skb_free_datagram (./include/net/sock.h:1578 ./include/net/sock.h:1639 net/core/datagram.c:323) bt_sock_recvmsg (net/bluetooth/af_bluetooth.c:295) bluetooth l2cap_sock_recvmsg (net/bluetooth/l2cap_sock.c:1212) bluetooth sock_read_iter (net/socket.c:1087) new_sync_read (./include/linux/fs.h:2052 fs/read_write.c:401) vfs_read (fs/read_write.c:482) ksys_read (fs/read_write.c:620) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)
{
"affected": [],
"aliases": [
"CVE-2022-49910"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-05-01T15:16:16Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu\n\nFix the race condition between the following two flows that run in\nparallel:\n\n1. l2cap_reassemble_sdu -\u003e chan-\u003eops-\u003erecv (l2cap_sock_recv_cb) -\u003e\n __sock_queue_rcv_skb.\n\n2. bt_sock_recvmsg -\u003e skb_recv_datagram, skb_free_datagram.\n\nAn SKB can be queued by the first flow and immediately dequeued and\nfreed by the second flow, therefore the callers of l2cap_reassemble_sdu\ncan\u0027t use the SKB after that function returns. However, some places\ncontinue accessing struct l2cap_ctrl that resides in the SKB\u0027s CB for a\nshort time after l2cap_reassemble_sdu returns, leading to a\nuse-after-free condition (the stack trace is below, line numbers for\nkernel 5.19.8).\n\nFix it by keeping a local copy of struct l2cap_ctrl.\n\nBUG: KASAN: use-after-free in l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth\nRead of size 1 at addr ffff88812025f2f0 by task kworker/u17:3/43169\n\nWorkqueue: hci0 hci_rx_work [bluetooth]\nCall Trace:\n \u003cTASK\u003e\n dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4))\n print_report.cold (mm/kasan/report.c:314 mm/kasan/report.c:429)\n ? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth\n kasan_report (mm/kasan/report.c:162 mm/kasan/report.c:493)\n ? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth\n l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth\n l2cap_rx (net/bluetooth/l2cap_core.c:7236 net/bluetooth/l2cap_core.c:7271) bluetooth\n ret_from_fork (arch/x86/entry/entry_64.S:306)\n \u003c/TASK\u003e\n\nAllocated by task 43169:\n kasan_save_stack (mm/kasan/common.c:39)\n __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469)\n kmem_cache_alloc_node (mm/slab.h:750 mm/slub.c:3243 mm/slub.c:3293)\n __alloc_skb (net/core/skbuff.c:414)\n l2cap_recv_frag (./include/net/bluetooth/bluetooth.h:425 net/bluetooth/l2cap_core.c:8329) bluetooth\n l2cap_recv_acldata (net/bluetooth/l2cap_core.c:8442) bluetooth\n hci_rx_work (net/bluetooth/hci_core.c:3642 net/bluetooth/hci_core.c:3832) bluetooth\n process_one_work (kernel/workqueue.c:2289)\n worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2437)\n kthread (kernel/kthread.c:376)\n ret_from_fork (arch/x86/entry/entry_64.S:306)\n\nFreed by task 27920:\n kasan_save_stack (mm/kasan/common.c:39)\n kasan_set_track (mm/kasan/common.c:45)\n kasan_set_free_info (mm/kasan/generic.c:372)\n ____kasan_slab_free (mm/kasan/common.c:368 mm/kasan/common.c:328)\n slab_free_freelist_hook (mm/slub.c:1780)\n kmem_cache_free (mm/slub.c:3536 mm/slub.c:3553)\n skb_free_datagram (./include/net/sock.h:1578 ./include/net/sock.h:1639 net/core/datagram.c:323)\n bt_sock_recvmsg (net/bluetooth/af_bluetooth.c:295) bluetooth\n l2cap_sock_recvmsg (net/bluetooth/l2cap_sock.c:1212) bluetooth\n sock_read_iter (net/socket.c:1087)\n new_sync_read (./include/linux/fs.h:2052 fs/read_write.c:401)\n vfs_read (fs/read_write.c:482)\n ksys_read (fs/read_write.c:620)\n do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80)\n entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120)",
"id": "GHSA-3vg9-6vwr-fh6q",
"modified": "2025-05-01T15:31:53Z",
"published": "2025-05-01T15:31:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49910"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/03af22e23b96fb7ef75fb7885407ef457e8b403d"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/3aff8aaca4e36dc8b17eaa011684881a80238966"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4cd094fd5d872862ca278e15b9b51b07e915ef3f"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6c7407bfbeafc80a04e6eaedcf34d378532a04f2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8278a87bb1eeea94350d675ef961ee5a03341fde"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9a04161244603f502c6e453913e51edd59cb70c1"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cb1c012099ef5904cd468bdb8d6fcdfdd9bcb569"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/dc30e05bb18852303084430c03ca76e69257d9ea"
}
],
"schema_version": "1.4.0",
"severity": []
}
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.