{
   "containers": {
      "cna": {
         "providerMetadata": {
            "orgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038"
         },
         "descriptions": [
            {
               "lang": "en",
               "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nxen/netfront: destroy queues before real_num_tx_queues is zeroed\n\nxennet_destroy_queues() relies on info->netdev->real_num_tx_queues to\ndelete queues. Since d7dac083414eb5bb99a6d2ed53dc2c1b405224e5\n(\"net-sysfs: update the queue counts in the unregistration path\"),\nunregister_netdev() indirectly sets real_num_tx_queues to 0. Those two\nfacts together means, that xennet_destroy_queues() called from\nxennet_remove() cannot do its job, because it's called after\nunregister_netdev(). This results in kfree-ing queues that are still\nlinked in napi, which ultimately crashes:\n\n    BUG: kernel NULL pointer dereference, address: 0000000000000000\n    #PF: supervisor read access in kernel mode\n    #PF: error_code(0x0000) - not-present page\n    PGD 0 P4D 0\n    Oops: 0000 [#1] PREEMPT SMP PTI\n    CPU: 1 PID: 52 Comm: xenwatch Tainted: G        W         5.16.10-1.32.fc32.qubes.x86_64+ #226\n    RIP: 0010:free_netdev+0xa3/0x1a0\n    Code: ff 48 89 df e8 2e e9 00 00 48 8b 43 50 48 8b 08 48 8d b8 a0 fe ff ff 48 8d a9 a0 fe ff ff 49 39 c4 75 26 eb 47 e8 ed c1 66 ff <48> 8b 85 60 01 00 00 48 8d 95 60 01 00 00 48 89 ef 48 2d 60 01 00\n    RSP: 0000:ffffc90000bcfd00 EFLAGS: 00010286\n    RAX: 0000000000000000 RBX: ffff88800edad000 RCX: 0000000000000000\n    RDX: 0000000000000001 RSI: ffffc90000bcfc30 RDI: 00000000ffffffff\n    RBP: fffffffffffffea0 R08: 0000000000000000 R09: 0000000000000000\n    R10: 0000000000000000 R11: 0000000000000001 R12: ffff88800edad050\n    R13: ffff8880065f8f88 R14: 0000000000000000 R15: ffff8880066c6680\n    FS:  0000000000000000(0000) GS:ffff8880f3300000(0000) knlGS:0000000000000000\n    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n    CR2: 0000000000000000 CR3: 00000000e998c006 CR4: 00000000003706e0\n    Call Trace:\n     <TASK>\n     xennet_remove+0x13d/0x300 [xen_netfront]\n     xenbus_dev_remove+0x6d/0xf0\n     __device_release_driver+0x17a/0x240\n     device_release_driver+0x24/0x30\n     bus_remove_device+0xd8/0x140\n     device_del+0x18b/0x410\n     ? _raw_spin_unlock+0x16/0x30\n     ? klist_iter_exit+0x14/0x20\n     ? xenbus_dev_request_and_reply+0x80/0x80\n     device_unregister+0x13/0x60\n     xenbus_dev_changed+0x18e/0x1f0\n     xenwatch_thread+0xc0/0x1a0\n     ? do_wait_intr_irq+0xa0/0xa0\n     kthread+0x16b/0x190\n     ? set_kthread_struct+0x40/0x40\n     ret_from_fork+0x22/0x30\n     </TASK>\n\nFix this by calling xennet_destroy_queues() from xennet_uninit(),\nwhen real_num_tx_queues is still available. This ensures that queues are\ndestroyed when real_num_tx_queues is set to 0, regardless of how\nunregister_netdev() was called.\n\nOriginally reported at\nhttps://github.com/QubesOS/qubes-issues/issues/7257"
            }
         ],
         "affected": [
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "drivers/net/xen-netfront.c"
               ],
               "versions": [
                  {
                     "version": "35cad2003b64",
                     "lessThan": "198cdc287769",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "a5d8e6189b13",
                     "lessThan": "b40c91262477",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "443133330a5d",
                     "lessThan": "a1753d5c29a6",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "0abd3f9903fa",
                     "lessThan": "a63eb1e4a2e1",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "c5eb468cbc1f",
                     "lessThan": "47e2f166ed9f",
                     "status": "affected",
                     "versionType": "git"
                  },
                  {
                     "version": "d7dac083414e",
                     "lessThan": "dcf4ff7a48e7",
                     "status": "affected",
                     "versionType": "git"
                  }
               ]
            },
            {
               "product": "Linux",
               "vendor": "Linux",
               "defaultStatus": "unaffected",
               "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
               "programFiles": [
                  "drivers/net/xen-netfront.c"
               ],
               "versions": [
                  {
                     "version": "4.19.226",
                     "lessThan": "4.19.233",
                     "status": "affected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.4.174",
                     "lessThan": "5.4.183",
                     "status": "affected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.10.94",
                     "lessThan": "5.10.104",
                     "status": "affected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.15.17",
                     "lessThan": "5.15.27",
                     "status": "affected",
                     "versionType": "custom"
                  },
                  {
                     "version": "5.16.3",
                     "lessThan": "5.16.13",
                     "status": "affected",
                     "versionType": "custom"
                  }
               ]
            }
         ],
         "references": [
            {
               "url": "https://git.kernel.org/stable/c/198cdc287769c717dafff5887c6125cb7a373bf3"
            },
            {
               "url": "https://git.kernel.org/stable/c/b40c912624775a21da32d1105e158db5f6d0554a"
            },
            {
               "url": "https://git.kernel.org/stable/c/a1753d5c29a6fb9a8966dcf04cb4f3b71e303ae8"
            },
            {
               "url": "https://git.kernel.org/stable/c/a63eb1e4a2e1a191a90217871e67fba42fd39255"
            },
            {
               "url": "https://git.kernel.org/stable/c/47e2f166ed9fe17f24561d6315be2228f6a90209"
            },
            {
               "url": "https://git.kernel.org/stable/c/dcf4ff7a48e7598e6b10126cc02177abb8ae4f3f"
            }
         ],
         "title": "xen/netfront: destroy queues before real_num_tx_queues is zeroed",
         "x_generator": {
            "engine": "bippy-c9c4e1df01b2"
         }
      }
   },
   "cveMetadata": {
      "assignerOrgId": "f4215fc3-5b6b-47ff-a258-f7189bd81038",
      "cveID": "CVE-2022-48914",
      "requesterUserId": "gregkh@kernel.org",
      "serial": "1",
      "state": "PUBLISHED"
   },
   "dataType": "CVE_RECORD",
   "dataVersion": "5.0"
}