ghsa-p98w-xrc8-4w6x
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: L2CAP: Fix memory leak in vhci_write
Syzkaller reports a memory leak as follows:
BUG: memory leak
unreferenced object 0xffff88810d81ac00 (size 240):
[...]
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[
HCI core will uses hci_rx_work() to process frame, which is queued to the hdev->rx_q tail in hci_recv_frame() by HCI driver.
Yet the problem is that, HCI core may not free the skb after handling ACL data packets. To be more specific, when start fragment does not contain the L2CAP length, HCI core just copies skb into conn->rx_skb and finishes frame process in l2cap_recv_acldata(), without freeing the skb, which triggers the above memory leak.
This patch solves it by releasing the relative skb, after processing the above case in l2cap_recv_acldata().
{
"affected": [],
"aliases": [
"CVE-2022-49908"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-05-01T15:16:15Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: Fix memory leak in vhci_write\n\nSyzkaller reports a memory leak as follows:\n====================================\nBUG: memory leak\nunreferenced object 0xffff88810d81ac00 (size 240):\n [...]\n hex dump (first 32 bytes):\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\n 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................\n backtrace:\n [\u003cffffffff838733d9\u003e] __alloc_skb+0x1f9/0x270 net/core/skbuff.c:418\n [\u003cffffffff833f742f\u003e] alloc_skb include/linux/skbuff.h:1257 [inline]\n [\u003cffffffff833f742f\u003e] bt_skb_alloc include/net/bluetooth/bluetooth.h:469 [inline]\n [\u003cffffffff833f742f\u003e] vhci_get_user drivers/bluetooth/hci_vhci.c:391 [inline]\n [\u003cffffffff833f742f\u003e] vhci_write+0x5f/0x230 drivers/bluetooth/hci_vhci.c:511\n [\u003cffffffff815e398d\u003e] call_write_iter include/linux/fs.h:2192 [inline]\n [\u003cffffffff815e398d\u003e] new_sync_write fs/read_write.c:491 [inline]\n [\u003cffffffff815e398d\u003e] vfs_write+0x42d/0x540 fs/read_write.c:578\n [\u003cffffffff815e3cdd\u003e] ksys_write+0x9d/0x160 fs/read_write.c:631\n [\u003cffffffff845e0645\u003e] do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n [\u003cffffffff845e0645\u003e] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80\n [\u003cffffffff84600087\u003e] entry_SYSCALL_64_after_hwframe+0x63/0xcd\n====================================\n\nHCI core will uses hci_rx_work() to process frame, which is queued to\nthe hdev-\u003erx_q tail in hci_recv_frame() by HCI driver.\n\nYet the problem is that, HCI core may not free the skb after handling\nACL data packets. To be more specific, when start fragment does not\ncontain the L2CAP length, HCI core just copies skb into conn-\u003erx_skb and\nfinishes frame process in l2cap_recv_acldata(), without freeing the skb,\nwhich triggers the above memory leak.\n\nThis patch solves it by releasing the relative skb, after processing\nthe above case in l2cap_recv_acldata().",
"id": "GHSA-p98w-xrc8-4w6x",
"modified": "2025-05-01T15:31:52Z",
"published": "2025-05-01T15:31:52Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-49908"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5b4f039a2f487c5edae681d763fe1af505f84c13"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7c9524d929648935bac2bbb4c20437df8f9c3f42"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/aa16cac06b752e5f609c106735bd7838f444784c"
}
],
"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.