{"cve":"CVE-2021-47540","nvd":{"published":"2024-05-24T15:15:18.147","modified":"2026-06-17T04:17:43.400","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmt76: mt7915: fix NULL pointer dereference in mt7915_get_phy_mode\n\nFix the following NULL pointer dereference in mt7915_get_phy_mode\nroutine adding an ibss interface to the mt7915 driver.\n\n[  101.137097] wlan0: Trigger new scan to find an IBSS to join\n[  102.827039] wlan0: Creating new IBSS network, BSSID 26:a4:50:1a:6e:69\n[  103.064756] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000\n[  103.073670] Mem abort info:\n[  103.076520]   ESR = 0x96000005\n[  103.079614]   EC = 0x25: DABT (current EL), IL = 32 bits\n[  103.084934]   SET = 0, FnV = 0\n[  103.088042]   EA = 0, S1PTW = 0\n[  103.091215] Data abort info:\n[  103.094104]   ISV = 0, ISS = 0x00000005\n[  103.098041]   CM = 0, WnR = 0\n[  103.101044] user pgtable: 4k pages, 39-bit VAs, pgdp=00000000460b1000\n[  103.107565] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000\n[  103.116590] Internal error: Oops: 96000005 [#1] SMP\n[  103.189066] CPU: 1 PID: 333 Comm: kworker/u4:3 Not tainted 5.10.75 #0\n[  103.195498] Hardware name: MediaTek MT7622 RFB1 board (DT)\n[  103.201124] Workqueue: phy0 ieee80211_iface_work [mac80211]\n[  103.206695] pstate: 20000005 (nzCv daif -PAN -UAO -TCO BTYPE=--)\n[  103.212705] pc : mt7915_get_phy_mode+0x68/0x120 [mt7915e]\n[  103.218103] lr : mt7915_mcu_add_bss_info+0x11c/0x760 [mt7915e]\n[  103.223927] sp : ffffffc011cdb9e0\n[  103.227235] x29: ffffffc011cdb9e0 x28: ffffff8006563098\n[  103.232545] x27: ffffff8005f4da22 x26: ffffff800685ac40\n[  103.237855] x25: 0000000000000001 x24: 000000000000011f\n[  103.243165] x23: ffffff8005f4e260 x22: ffffff8006567918\n[  103.248475] x21: ffffff8005f4df80 x20: ffffff800685ac58\n[  103.253785] x19: ffffff8006744400 x18: 0000000000000000\n[  103.259094] x17: 0000000000000000 x16: 0000000000000001\n[  103.264403] x15: 000899c3a2d9d2e4 x14: 000899bdc3c3a1c8\n[  103.269713] x13: 0000000000000000 x12: 0000000000000000\n[  103.275024] x11: ffffffc010e30c20 x10: 0000000000000000\n[  103.280333] x9 : 0000000000000050 x8 : ffffff8006567d88\n[  103.285642] x7 : ffffff8006563b5c x6 : ffffff8006563b44\n[  103.290952] x5 : 0000000000000002 x4 : 0000000000000001\n[  103.296262] x3 : 0000000000000001 x2 : 0000000000000001\n[  103.301572] x1 : 0000000000000000 x0 : 0000000000000011\n[  103.306882] Call trace:\n[  103.309328]  mt7915_get_phy_mode+0x68/0x120 [mt7915e]\n[  103.314378]  mt7915_bss_info_changed+0x198/0x200 [mt7915e]\n[  103.319941]  ieee80211_bss_info_change_notify+0x128/0x290 [mac80211]\n[  103.326360]  __ieee80211_sta_join_ibss+0x308/0x6c4 [mac80211]\n[  103.332171]  ieee80211_sta_create_ibss+0x8c/0x10c [mac80211]\n[  103.337895]  ieee80211_ibss_work+0x3dc/0x614 [mac80211]\n[  103.343185]  ieee80211_iface_work+0x388/0x3f0 [mac80211]\n[  103.348495]  process_one_work+0x288/0x690\n[  103.352499]  worker_thread+0x70/0x464\n[  103.356157]  kthread+0x144/0x150\n[  103.359380]  ret_from_fork+0x10/0x18\n[  103.362952] Code: 394008c3 52800220 394000e4 7100007f (39400023)","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/14b03b8cebdf18ff13c39d58501b625411314de2","https://git.kernel.org/stable/c/6e53d6d26920d5221d3f4d4f5ffdd629ea69aa5c","https://git.kernel.org/stable/c/932b338f4e5c4cb0c2ed640da3bced1e63620198","https://git.kernel.org/stable/c/14b03b8cebdf18ff13c39d58501b625411314de2","https://git.kernel.org/stable/c/6e53d6d26920d5221d3f4d4f5ffdd629ea69aa5c"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47540","score":0.00236,"percentile":0.14582,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}