CVE-2021-47540

MEDIUM
Published May 24, 2024 Modified Nov 21, 2024 CWE-476

Description

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)

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CVSS v3.1 Score

5.5
MEDIUM
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Weakness Type (CWE)

CWE-476 CWE-476

Affected Products

Vendor Product
linux linux_kernel
linux linux_kernel

References

Frequently Asked Questions

What is CVE-2021-47540? +
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) It has a CVSS v3.1 base score of 5.5 (MEDIUM).
How severe is CVE-2021-47540? +
CVE-2021-47540 has a CVSS v3.1 score of 5.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance.
What products are affected by CVE-2021-47540? +
CVE-2021-47540 affects products from linux, specifically: linux_kernel. Check the affected products table above for specific version ranges.
How do I check if I'm vulnerable to CVE-2021-47540? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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