Vulnerabilidad en kernel de Linux (CVE-2021-47540)

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mt76: mt7915: corrige la desreferencia del puntero NULL en mt7915_get_phy_mode. Corrija la siguiente desreferencia del puntero NULL en la rutina mt7915_get_phy_mode agregando una interfaz ibss al controlador mt7915. [ 101.137097] wlan0: activa una nueva exploración para encontrar un IBSS al que unirse [ 102.827039] wlan0: crea una nueva red IBSS, BSSID 26:a4:50:1a:6e:69 [ 103.064756] No se puede manejar la desreferencia del puntero NULL del kernel en la dirección virtual 0000000000000000 [ 103.073670] Información de cancelación de memoria: [ 103.076520] ESR = 0x96000005 [ 103.079614] EC = 0x25: DABT (EL actual), IL = 32 bits [ 103.084934] SET = 0, FnV = 0 [ 103.088042] EA = 0, 1PTW = 0 [ 103.091215] Información de cancelación de datos: [ 103.094104] ISV = 0, ISS = 0x00000005 [ 103.098041] CM = 0, WnR = 0 [ 103.101044] tabla de páginas de usuario: páginas de 4k, VA de 39 bits, pgdp=00000000460 b1000 [ 103.107565 ] [0000000000000000] pgd=0000000000000000, p4d=0000000000000000, pud=0000000000000000 [103.116590] Error interno: Ups: 96000005 [#1] SMP [103.189066] CPU: 1 PID: 333 Comunicaciones: kworker/u4:3 No contaminado 5.10.75 #0 [ 103.195498 ] Nombre del hardware: Placa MediaTek MT7622 RFB1 (DT) [103.201124] Cola de trabajo: phy0 ieee80211_iface_work [mac80211] [103.206695] pstate: 20000005 (nzCv daif -PAN -UAO -TCO BTYPE=--) [103.212705] pc: t7915_get_phy_mode+0x68/ 0x120 [MT7915E] [103.218103] LR: MT7915_MCU_ADD_BSS_INFO+0X11C/0X760 [MT7915E] [103.223927] SP: FFFFFFFC011CDB9E0 [103.222235] x29: F8006563098 [103.232545] x27: ffffff8005f4da22 x26: ffffff800685ac40 [103.237855] x25: 000000000000000001 x24: 000000000000011f [ 103.243165] x23: ffffff8005f4e260 x22: ffffff8006567918 [ 103.248475] x21: ffffff8005f4df80 x20: ffffff800685ac58 [ 103.253785] x19: 44400 x18: 0000000000000000 [ 103.259094] x17: 0000000000000000 x16: 0000000000000001 [ 103.264403] x15: 000899c3a2d9d2e4 x14: 99bdc3c3a1c8 [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: 00000000000000002 x4: 0000000000000001 [ 103.2 96262] x3: 0000000000000001 x2: 0000000000000001 [ 103.301572] x1: 0000000000000000 x0: 0000000000000011 [103.306882] Rastreo de llamadas: [103.309328] mt7915_get_phy_mode+0x68/0x120 [mt7915e] [ 378] 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] 614 [mac80211] [ 103.343185] ieee80211_iface_work+0x388/0x3f0 [mac80211] [ 103.348495] Process_one_work+0x288/0x690 [ 103.352499] work_thread+0x70/0x464 [ 103.356157] kthread+0x144/0x150 [ 103.359380] ret_from_fork+0x10/0x18 [ 103.362952] Código: 394008c3 52800220 00e4 7100007f (39400023)