CVE-2021-47349

2024-05-2115:15:21

416baaa9-dc9f-4396-8d5f-8c081fb06d67

web.nvd.nist.gov

linux kernel

mwifiex

deadlock

6.7 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

15.6%

JSON

In the Linux kernel, the following vulnerability has been resolved:

mwifiex: bring down link before deleting interface

We can deadlock when rmmod’ing the driver or going through firmware
reset, because the cfg80211_unregister_wdev() has to bring down the link
for us, … which then grab the same wiphy lock.

nl80211_del_interface() already handles a very similar case, with a nice
description:

    /*
     * We hold RTNL, so this is safe, without RTNL opencount cannot
     * reach 0, and thus the rdev cannot be deleted.
     *
     * We need to do it for the dev_close(), since that will call
     * the netdev notifiers, and we need to acquire the mutex there
     * but don't know if we get there from here or from some other
     * place (e.g. "ip link set ... down").
     */
    mutex_unlock(&rdev-&gt;wiphy.mtx);

…

Do similarly for mwifiex teardown, by ensuring we bring the link down
first.

Sample deadlock trace:

[ 247.103516] INFO: task rmmod:2119 blocked for more than 123 seconds.
[ 247.110630] Not tainted 5.12.4 #5
[ 247.115796] “echo 0 > /proc/sys/kernel/hung_task_timeout_secs” disables this message.
[ 247.124557] task:rmmod state:D stack: 0 pid: 2119 ppid: 2114 flags:0x00400208
[ 247.133905] Call trace:
[ 247.136644] __switch_to+0x130/0x170
[ 247.140643] __schedule+0x714/0xa0c
[ 247.144548] schedule_preempt_disabled+0x88/0xf4
[ 247.149714] __mutex_lock_common+0x43c/0x750
[ 247.154496] mutex_lock_nested+0x5c/0x68
[ 247.158884] cfg80211_netdev_notifier_call+0x280/0x4e0 [cfg80211]
[ 247.165769] raw_notifier_call_chain+0x4c/0x78
[ 247.170742] call_netdevice_notifiers_info+0x68/0xa4
[ 247.176305] __dev_close_many+0x7c/0x138
[ 247.180693] dev_close_many+0x7c/0x10c
[ 247.184893] unregister_netdevice_many+0xfc/0x654
[ 247.190158] unregister_netdevice_queue+0xb4/0xe0
[ 247.195424] _cfg80211_unregister_wdev+0xa4/0x204 [cfg80211]
[ 247.201816] cfg80211_unregister_wdev+0x20/0x2c [cfg80211]
[ 247.208016] mwifiex_del_virtual_intf+0xc8/0x188 [mwifiex]
[ 247.214174] mwifiex_uninit_sw+0x158/0x1b0 [mwifiex]
[ 247.219747] mwifiex_remove_card+0x38/0xa0 [mwifiex]
[ 247.225316] mwifiex_pcie_remove+0xd0/0xe0 [mwifiex_pcie]
[ 247.231451] pci_device_remove+0x50/0xe0
[ 247.235849] device_release_driver_internal+0x110/0x1b0
[ 247.241701] driver_detach+0x5c/0x9c
[ 247.245704] bus_remove_driver+0x84/0xb8
[ 247.250095] driver_unregister+0x3c/0x60
[ 247.254486] pci_unregister_driver+0x2c/0x90
[ 247.259267] cleanup_module+0x18/0xcdc [mwifiex_pcie]

Affected configurations

Vulners

Node

linuxlinux_kernelRange5.12–5.12.18

linuxlinux_kernelRange5.13.0–5.13.3

linuxlinux_kernelRange5.14.0≥

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/wireless/marvell/mwifiex/main.c"
    ],
    "versions": [
      {
        "version": "a05829a7222e",
        "lessThan": "a3041d39d3c1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "a05829a7222e",
        "lessThan": "35af69c7c049",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "a05829a7222e",
        "lessThan": "1f9482aa8d41",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/net/wireless/marvell/mwifiex/main.c"
    ],
    "versions": [
      {
        "version": "5.12",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.12",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.18",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13.3",
        "lessThanOrEqual": "5.13.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.14",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]