"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nxen/netback: avoid entering xenvif_rx_next_skb() with an empty rx queue\n\nxenvif_rx_next_skb() is expecting the rx queue not being empty, but\nin case the loop in xenvif_rx_action() is doing multiple iterations,\nthe availability of another skb in the rx queue is not being checked.\n\nThis can lead to crashes:\n\n[40072.537261] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080\n[40072.537407] IP: xenvif_rx_skb+0x23/0x590 [xen_netback]\n[40072.537534] PGD 0 P4D 0\n[40072.537644] Oops: 0000 [#1] SMP NOPTI\n[40072.537749] CPU: 0 PID: 12505 Comm: v1-c40247-q2-gu Not tainted 4.12.14-122.121-default #1 SLE12-SP5\n[40072.537867] Hardware name: HP ProLiant DL580 Gen9/ProLiant DL580 Gen9, BIOS U17 11/23/2021\n[40072.537999] task: ffff880433b38100 task.stack: ffffc90043d40000\n[40072.538112] RIP: e030:xenvif_rx_skb+0x23/0x590 [xen_netback]\n[40072.538217] RSP: e02b:ffffc90043d43de0 EFLAGS: 00010246\n[40072.538319] RAX: 0000000000000000 RBX: ffffc90043cd7cd0 RCX: 00000000000000f7\n[40072.538430] RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffffc90043d43df8\n[40072.538531] RBP: 000000000000003f R08: 000077ff80000000 R09: 0000000000000008\n[40072.538644] R10: 0000000000007ff0 R11: 00000000000008f6 R12: ffffc90043ce2708\n[40072.538745] R13: 0000000000000000 R14: ffffc90043d43ed0 R15: ffff88043ea748c0\n[40072.538861] FS: 0000000000000000(0000) GS:ffff880484600000(0000) knlGS:0000000000000000\n[40072.538988] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033\n[40072.539088] CR2: 0000000000000080 CR3: 0000000407ac8000 CR4: 0000000000040660\n[40072.539211] Call Trace:\n[40072.539319] xenvif_rx_action+0x71/0x90 [xen_netback]\n[40072.539429] xenvif_kthread_guest_rx+0x14a/0x29c [xen_netback]\n\nFix that by stopping the loop in case the rx queue becomes empty."
"value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: xen/netback: evitar ingresar a xenvif_rx_next_skb() con una cola rx vac\u00eda xenvif_rx_next_skb() espera que la cola rx no est\u00e9 vac\u00eda, pero en caso de que el bucle en xenvif_rx_action() est\u00e9 realizando m\u00faltiples iteraciones, no se verifica la disponibilidad de otro skb en la cola rx. Esto puede provocar fallos: [40072.537261] ERROR: no se puede gestionar la desreferencia del puntero NULL del n\u00facleo en 0000000000000080 [40072.537407] IP: xenvif_rx_skb+0x23/0x590 [xen_netback] [40072.537534] PGD 0 P4D 0 [40072.537644] Oops: 0000 [#1] SMP NOPTI [40072.537749] CPU: 0 PID: 12505 Comm: v1-c40247-q2-gu Not tainted 4.12.14-122.121-default #1 SLE12-SP5 [40072.537867] Hardware name: HP ProLiant DL580 Gen9/ProLiant DL580 Gen9, BIOS U17 11/23/2021 [40072.537999] task: ffff880433b38100 task.stack: ffffc90043d40000 [40072.538112] RIP: e030:xenvif_rx_skb+0x23/0x590 [xen_netback] [40072.538217] RSP: e02b:ffffc90043d43de0 EFLAGS: 00010246 [40072.538319] RAX: 0000000000000000 RBX: ffffc90043cd7cd0 RCX: 00000000000000f7 [40072.538430] RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffffc90043d43df8 [40072.538531] RBP: 000000000000003f R08: 000077ff80000000 R09: 0000000000000008 [40072.538644] R10: 0000000000007ff0 R11: 00000000000008f6 R12: ffffc90043ce2708 [40072.538745] R13: 0000000000000000 R14: ffffc90043d43ed0 R15: ffff88043ea748c0 [40072.538861] FS: 0000000000000000(0000) GS:ffff880484600000(0000) knlGS:0000000000000000 [40072.538988] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 [40072.539088] CR2: 0000000000000080 CR3: 0000000407ac8000 CR4: 0000000000040660 [40072.539211] Call Trace: [40072.539319] xenvif_rx_action+0x71/0x90 [xen_netback] [40072.539429] xenvif_kthread_guest_rx+0x14a/0x29c [xen_netback] Solucione esto deteniendo el bucle en caso de que la cola de recepci\u00f3n se vac\u00ede."