CVE-2021-47540

2024-05-2415:15:18

CWE-476

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

web.nvd.nist.gov

linux kernel

mt7915 driver

null pointer dereference

vulnerability

fix

5.5 Medium

CVSS3

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

NONE

Integrity Impact

NONE

Availability Impact

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

6.5 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

5.1%

JSON

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

mt76: mt7915: fix NULL pointer dereference in mt7915_get_phy_mode

Fix the following NULL pointer dereference in mt7915_get_phy_mode
routine adding an ibss interface to the mt7915 driver.

[ 101.137097] wlan0: Trigger new scan to find an IBSS to join
[ 102.827039] wlan0: Creating new IBSS network, BSSID 26:a4:50:1a:6e:69
[ 103.064756] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
[ 103.073670] Mem abort info:
[ 103.076520] ESR = 0x96000005
[ 103.079614] EC = 0x25: DABT (current EL), IL = 32 bits
[ 103.084934] SET = 0, FnV = 0
[ 103.088042] EA = 0, S1PTW = 0
[ 103.091215] Data abort info:
[ 103.094104] ISV = 0, ISS = 0x00000005
[ 103.098041] CM = 0, WnR = 0
[ 103.101044] user pgtable: 4k pages, 39-bit VAs, pgdp=00000000460b1000
[ 103.107565] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000
[ 103.116590] Internal error: Oops: 96000005 [#1] SMP
[ 103.189066] CPU: 1 PID: 333 Comm: kworker/u4:3 Not tainted 5.10.75 #0
[ 103.195498] Hardware name: MediaTek MT7622 RFB1 board (DT)
[ 103.201124] Workqueue: phy0 ieee80211_iface_work [mac80211]
[ 103.206695] pstate: 20000005 (nzCv daif -PAN -UAO -TCO BTYPE=–)
[ 103.212705] pc : mt7915_get_phy_mode+0x68/0x120 [mt7915e]
[ 103.218103] lr : mt7915_mcu_add_bss_info+0x11c/0x760 [mt7915e]
[ 103.223927] sp : ffffffc011cdb9e0
[ 103.227235] x29: ffffffc011cdb9e0 x28: ffffff8006563098
[ 103.232545] x27: ffffff8005f4da22 x26: ffffff800685ac40
[ 103.237855] x25: 0000000000000001 x24: 000000000000011f
[ 103.243165] x23: ffffff8005f4e260 x22: ffffff8006567918
[ 103.248475] x21: ffffff8005f4df80 x20: ffffff800685ac58
[ 103.253785] x19: ffffff8006744400 x18: 0000000000000000
[ 103.259094] x17: 0000000000000000 x16: 0000000000000001
[ 103.264403] x15: 000899c3a2d9d2e4 x14: 000899bdc3c3a1c8
[ 103.269713] x13: 0000000000000000 x12: 0000000000000000
[ 103.275024] x11: ffffffc010e30c20 x10: 0000000000000000
[ 103.280333] x9 : 0000000000000050 x8 : ffffff8006567d88
[ 103.285642] x7 : ffffff8006563b5c x6 : ffffff8006563b44
[ 103.290952] x5 : 0000000000000002 x4 : 0000000000000001
[ 103.296262] x3 : 0000000000000001 x2 : 0000000000000001
[ 103.301572] x1 : 0000000000000000 x0 : 0000000000000011
[ 103.306882] Call trace:
[ 103.309328] mt7915_get_phy_mode+0x68/0x120 [mt7915e]
[ 103.314378] mt7915_bss_info_changed+0x198/0x200 [mt7915e]
[ 103.319941] ieee80211_bss_info_change_notify+0x128/0x290 [mac80211]
[ 103.326360] __ieee80211_sta_join_ibss+0x308/0x6c4 [mac80211]
[ 103.332171] ieee80211_sta_create_ibss+0x8c/0x10c [mac80211]
[ 103.337895] ieee80211_ibss_work+0x3dc/0x614 [mac80211]
[ 103.343185] ieee80211_iface_work+0x388/0x3f0 [mac80211]
[ 103.348495] process_one_work+0x288/0x690
[ 103.352499] worker_thread+0x70/0x464
[ 103.356157] kthread+0x144/0x150
[ 103.359380] ret_from_fork+0x10/0x18
[ 103.362952] Code: 394008c3 52800220 394000e4 7100007f (39400023)

Affected configurations

Vulners

NVD

Node

linuxlinux_kernelRange5.8–5.10.84

linuxlinux_kernelRange5.11.0–5.15.7

linuxlinux_kernelRange5.16.0≥

CPENameOperatorVersion
linux:linux_kernellinux linux kernellt5.10.84
linux:linux_kernellinux linux kernellt5.15.7

CPE	Name	Operator	Version
linux:linux_kernel	linux linux kernel	lt	5.10.84
linux:linux_kernel	linux linux kernel	lt	5.15.7

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/mediatek/mt76/mt7915/mcu.c"
    ],
    "versions": [
      {
        "version": "37f4ca907c46",
        "lessThan": "932b338f4e5c",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "37f4ca907c46",
        "lessThan": "14b03b8cebdf",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "37f4ca907c46",
        "lessThan": "6e53d6d26920",
        "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/mediatek/mt76/mt7915/mcu.c"
    ],
    "versions": [
      {
        "version": "5.8",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "5.8",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.84",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.15.7",
        "lessThanOrEqual": "5.15.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.16",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]