ghsa-hfjw-rcpx-5rv6
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
vhost-vdpa: fix an iotlb memory leak
Before commit 3d5698793897 ("vhost-vdpa: introduce asid based IOTLB") we called vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1) during release to free all the resources allocated when processing user IOTLB messages through vhost_vdpa_process_iotlb_update(). That commit changed the handling of IOTLB a bit, and we accidentally removed some code called during the release.
We partially fixed this with commit 037d4305569a ("vhost-vdpa: call vhost_vdpa_cleanup during the release") but a potential memory leak is still there as showed by kmemleak if the application does not send VHOST_IOTLB_INVALIDATE or crashes:
unreferenced object 0xffff888007fbaa30 (size 16): comm "blkio-bench", pid 914, jiffies 4294993521 (age 885.500s) hex dump (first 16 bytes): 40 73 41 07 80 88 ff ff 00 00 00 00 00 00 00 00 @sA............. backtrace: [<0000000087736d2a>] kmem_cache_alloc_trace+0x142/0x1c0 [<0000000060740f50>] vhost_vdpa_process_iotlb_msg+0x68c/0x901 [vhost_vdpa] [<0000000083e8e205>] vhost_chr_write_iter+0xc0/0x4a0 [vhost] [<000000008f2f414a>] vhost_vdpa_chr_write_iter+0x18/0x20 [vhost_vdpa] [<00000000de1cd4a0>] vfs_write+0x216/0x4b0 [<00000000a2850200>] ksys_write+0x71/0xf0 [<00000000de8e720b>] __x64_sys_write+0x19/0x20 [<0000000018b12cbb>] do_syscall_64+0x3f/0x90 [<00000000986ec465>] entry_SYSCALL_64_after_hwframe+0x63/0xcd
Let's fix this calling vhost_vdpa_iotlb_unmap() on the whole range in vhost_vdpa_remove_as(). We move that call before vhost_dev_cleanup() since we need a valid v->vdev.mm in vhost_vdpa_pa_unmap(). vhost_iotlb_reset() call can be removed, since vhost_vdpa_iotlb_unmap() on the whole range removes all the entries.
The kmemleak log reported was observed with a vDPA device that has use_va
set to true (e.g. VDUSE). This patch has been tested with both types of
devices.
{
"affected": [],
"aliases": [
"CVE-2022-50738"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-12-24T13:16:00Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nvhost-vdpa: fix an iotlb memory leak\n\nBefore commit 3d5698793897 (\"vhost-vdpa: introduce asid based IOTLB\")\nwe called vhost_vdpa_iotlb_unmap(v, iotlb, 0ULL, 0ULL - 1) during\nrelease to free all the resources allocated when processing user IOTLB\nmessages through vhost_vdpa_process_iotlb_update().\nThat commit changed the handling of IOTLB a bit, and we accidentally\nremoved some code called during the release.\n\nWe partially fixed this with commit 037d4305569a (\"vhost-vdpa: call\nvhost_vdpa_cleanup during the release\") but a potential memory leak is\nstill there as showed by kmemleak if the application does not send\nVHOST_IOTLB_INVALIDATE or crashes:\n\n unreferenced object 0xffff888007fbaa30 (size 16):\n comm \"blkio-bench\", pid 914, jiffies 4294993521 (age 885.500s)\n hex dump (first 16 bytes):\n 40 73 41 07 80 88 ff ff 00 00 00 00 00 00 00 00 @sA.............\n backtrace:\n [\u003c0000000087736d2a\u003e] kmem_cache_alloc_trace+0x142/0x1c0\n [\u003c0000000060740f50\u003e] vhost_vdpa_process_iotlb_msg+0x68c/0x901 [vhost_vdpa]\n [\u003c0000000083e8e205\u003e] vhost_chr_write_iter+0xc0/0x4a0 [vhost]\n [\u003c000000008f2f414a\u003e] vhost_vdpa_chr_write_iter+0x18/0x20 [vhost_vdpa]\n [\u003c00000000de1cd4a0\u003e] vfs_write+0x216/0x4b0\n [\u003c00000000a2850200\u003e] ksys_write+0x71/0xf0\n [\u003c00000000de8e720b\u003e] __x64_sys_write+0x19/0x20\n [\u003c0000000018b12cbb\u003e] do_syscall_64+0x3f/0x90\n [\u003c00000000986ec465\u003e] entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nLet\u0027s fix this calling vhost_vdpa_iotlb_unmap() on the whole range in\nvhost_vdpa_remove_as(). We move that call before vhost_dev_cleanup()\nsince we need a valid v-\u003evdev.mm in vhost_vdpa_pa_unmap().\nvhost_iotlb_reset() call can be removed, since vhost_vdpa_iotlb_unmap()\non the whole range removes all the entries.\n\nThe kmemleak log reported was observed with a vDPA device that has `use_va`\nset to true (e.g. VDUSE). This patch has been tested with both types of\ndevices.",
"id": "GHSA-hfjw-rcpx-5rv6",
"modified": "2025-12-24T15:30:33Z",
"published": "2025-12-24T15:30:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-50738"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/4e92cb33bfb51eee5f28bb10846c46f266a4bb67"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a2907867e2c86067accd2f011d6f23ee5533aa6c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c070c1912a83432530cbb4271d5b9b11fa36b67a"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
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