CVE-2021-47023

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: net: marvell: prestera: corrige el manejo de eventos del puerto en init Por alguna razón, puede haber una falla durante la creación de puertos si los eventos del puerto se manejan al mismo tiempo porque fw puede enviar el puerto inicial evento con estado inactivo. El bloqueo apunta a cancel_delayed_work(), que se llama cuando el puerto está inactivo. Actualmente no descubrí la causa real del problema, así que lo solucioné cancelando las estadísticas del puerto solo si el estado del puerto anterior estaba activo y funcionando. El siguiente es el fallo que se puede desencadenar: [28.311104] No se puede manejar la solicitud de paginación del kernel en la dirección virtual 000071775f776600 [28.319097] Información de cancelación de memoria: [28.321914] ESR = 0x96000004 [28.324996] EC = 0x25: DABT (EL actual), IL = 32 bits [ 28.330350] SET = 0, FnV = 0 [ 28.333430] EA = 0, S1PTW = 0 [ 28.336597] Información de cancelación de datos: [ 28.339499] ISV = 0, ISS = 0x00000004 [ 28.343362] CM = 0, WnR = 0 [ 28.346354] tabla de páginas de usuario: páginas de 4k, VA de 48 bits, pgdp=0000000100bf7000 [ 28.352842] [000071775f776600] pgd=00000000000000000, p4d=0000000000000000 [ 28.359695] Error interno: Ups: 96000004 [#1] PREEMPT SMP [ 28.365310] Módulos vinculados en: prestera_pci(+) prestera uio_pdrv_genirq [ 28.372005] CPU: 0 PID: 1291 Comm: kworker/0:1H No contaminado 5.11.0-rc4 #1 [ 28.378846] Nombre de hardware: DNI Placa AmazonGo1 A7040 (DT) [ 28.384283] Cola de trabajo : prestera_fw_wq prestera_fw_evt_work_fn [prestera_pci] [ 28.391413] pstate: 60000085 (nZCv daIf -PAN -UAO -TCO BTYPE=--) [ 28.397468] pc : get_work_pool+0x48/0x60 [ 28.401442] lr : try_to _grab_pending+0x6c/0x1b0 [28.406018] sp : ffff80001391bc60 [ 28.409358] x29: ffff80001391bc60 x28: 0000000000000000 [ 28.414725] x27: ffff000104fc8b40 x26: ffff80001127de88 [ 28.4200 89] x25: 0000000000000000 x24: ffff000106119760 [ 28.425452] x23: ffff00010775dd60 x22: ffff00010567e000 [ 28.430814] x21: 000000000000000000 x20: ffff80001391bcb0 [28.436175] x19: ffff00010775deb8 x18: 00000000000000c0 [ 28.441537] x17: 0000000000000000 x16: 000000008d9b0e88 [ 28.446898] x15: 00000000000000 01 x14: 00000000000002ba [ 28.452261] x13: 80a3002c00000002 x12: 00000000000005f4 [ 28.457622] x11: 0000000000000030 x10: 00000000000 0000c [28.462985] x9: 000000000000000c x8: 0000000000000030 [28.468346] x7: ffff800014400000 x6: ffff000106119758 [28.473708] x5: 00000000000000003 x4: ffff00010775dc60 [28.4790 68] x3: 0000000000000000 x2: 00000000000000060 [28.484429] x1: 000071775f776600 x0: ffff00010775deb8 [28.489791] Rastreo de llamadas: [28.492259] get_work_pool+ 0x48/ 0x60 [ 28.495874] cancel_delayed_work+0x38/0xb0 [ 28.500011] prestera_port_handle_event+0x90/0xa0 [prestera] [ 28.505743] prestera_evt_recv+0x98/0xe0 [prestera] [ 28.510683] prestera_fw _evt_work_fn+0x180/0x228 [prestera_pci] [ 28.516660] proceso_one_work+0x1e8/0x360 [ 28.520710] work_thread+0x44/0x480 [ 28.524412] kthread+0x154/0x160 [ 28.527670] ret_from_fork+0x10/0x38 [ 28.531290] Código: a8c17bfd d50323bf d65f03c0 92 78dc21 (f9400020) [28.537429] ---[ final de seguimiento 5eced933df3a080b ]---

In the Linux kernel, the following vulnerability has been resolved: net: marvell: prestera: fix port event handling on init For some reason there might be a crash during ports creation if port events are handling at the same time because fw may send initial port event with down state. The crash points to cancel_delayed_work() which is called when port went is down. Currently I did not find out the real cause of the issue, so fixed it by cancel port stats work only if previous port's state was up & runnig. The following is the crash which can be triggered: [ 28.311104] Unable to handle kernel paging request at virtual address 000071775f776600 [ 28.319097] Mem abort info: [ 28.321914] ESR = 0x96000004 [ 28.324996] EC = 0x25: DABT (current EL), IL = 32 bits [ 28.330350] SET = 0, FnV = 0 [ 28.333430] EA = 0, S1PTW = 0 [ 28.336597] Data abort info: [ 28.339499] ISV = 0, ISS = 0x00000004 [ 28.343362] CM = 0, WnR = 0 [ 28.346354] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000100bf7000 [ 28.352842] [000071775f776600] pgd=0000000000000000, p4d=0000000000000000 [ 28.359695] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 28.365310] Modules linked in: prestera_pci(+) prestera uio_pdrv_genirq [ 28.372005] CPU: 0 PID: 1291 Comm: kworker/0:1H Not tainted 5.11.0-rc4 #1 [ 28.378846] Hardware name: DNI AmazonGo1 A7040 board (DT) [ 28.384283] Workqueue: prestera_fw_wq prestera_fw_evt_work_fn [prestera_pci] [ 28.391413] pstate: 60000085 (nZCv daIf -PAN -UAO -TCO BTYPE=--) [ 28.397468] pc : get_work_pool+0x48/0x60 [ 28.401442] lr : try_to_grab_pending+0x6c/0x1b0 [ 28.406018] sp : ffff80001391bc60 [ 28.409358] x29: ffff80001391bc60 x28: 0000000000000000 [ 28.414725] x27: ffff000104fc8b40 x26: ffff80001127de88 [ 28.420089] x25: 0000000000000000 x24: ffff000106119760 [ 28.425452] x23: ffff00010775dd60 x22: ffff00010567e000 [ 28.430814] x21: 0000000000000000 x20: ffff80001391bcb0 [ 28.436175] x19: ffff00010775deb8 x18: 00000000000000c0 [ 28.441537] x17: 0000000000000000 x16: 000000008d9b0e88 [ 28.446898] x15: 0000000000000001 x14: 00000000000002ba [ 28.452261] x13: 80a3002c00000002 x12: 00000000000005f4 [ 28.457622] x11: 0000000000000030 x10: 000000000000000c [ 28.462985] x9 : 000000000000000c x8 : 0000000000000030 [ 28.468346] x7 : ffff800014400000 x6 : ffff000106119758 [ 28.473708] x5 : 0000000000000003 x4 : ffff00010775dc60 [ 28.479068] x3 : 0000000000000000 x2 : 0000000000000060 [ 28.484429] x1 : 000071775f776600 x0 : ffff00010775deb8 [ 28.489791] Call trace: [ 28.492259] get_work_pool+0x48/0x60 [ 28.495874] cancel_delayed_work+0x38/0xb0 [ 28.500011] prestera_port_handle_event+0x90/0xa0 [prestera] [ 28.505743] prestera_evt_recv+0x98/0xe0 [prestera] [ 28.510683] prestera_fw_evt_work_fn+0x180/0x228 [prestera_pci] [ 28.516660] process_one_work+0x1e8/0x360 [ 28.520710] worker_thread+0x44/0x480 [ 28.524412] kthread+0x154/0x160 [ 28.527670] ret_from_fork+0x10/0x38 [ 28.531290] Code: a8c17bfd d50323bf d65f03c0 9278dc21 (f9400020) [ 28.537429] ---[ end trace 5eced933df3a080b ]---