"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmptcp: Fix crash due to tcp_tsorted_anchor was initialized before release skb\n\nGot crash when doing pressure test of mptcp:\n\n===========================================================================\ndst_release: dst:ffffa06ce6e5c058 refcnt:-1\nkernel tried to execute NX-protected page - exploit attempt? (uid: 0)\nBUG: unable to handle kernel paging request at ffffa06ce6e5c058\nPGD 190a01067 P4D 190a01067 PUD 43fffb067 PMD 22e403063 PTE 8000000226e5c063\nOops: 0011 [#1] SMP PTI\nCPU: 7 PID: 7823 Comm: kworker/7:0 Kdump: loaded Tainted: G E\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.2.1 04/01/2014\nCall Trace:\n ? skb_release_head_state+0x68/0x100\n ? skb_release_all+0xe/0x30\n ? kfree_skb+0x32/0xa0\n ? mptcp_sendmsg_frag+0x57e/0x750\n ? __mptcp_retrans+0x21b/0x3c0\n ? __switch_to_asm+0x35/0x70\n ? mptcp_worker+0x25e/0x320\n ? process_one_work+0x1a7/0x360\n ? worker_thread+0x30/0x390\n ? create_worker+0x1a0/0x1a0\n ? kthread+0x112/0x130\n ? kthread_flush_work_fn+0x10/0x10\n ? ret_from_fork+0x35/0x40\n===========================================================================\n\nIn __mptcp_alloc_tx_skb skb was allocated and skb->tcp_tsorted_anchor will\nbe initialized, in under memory pressure situation sk_wmem_schedule will\nreturn false and then kfree_skb. In this case skb->_skb_refdst is not null\nbecause_skb_refdst and tcp_tsorted_anchor are stored in the same mem, and\nkfree_skb will try to release dst and cause crash."
"value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mptcp: Se corrigi\u00f3 el bloqueo debido a que tcp_tsorted_anchor se inicializ\u00f3 antes del lanzamiento de skb Se produjo un bloqueo al realizar una prueba de presi\u00f3n de mptcp: ==================================================================================== dst_release: dst:ffffa06ce6e5c058 refcnt:-1 el kernel intent\u00f3 ejecutar una p\u00e1gina protegida por NX: \u00bfintento de explotaci\u00f3n? (uid: 0) ERROR: no se puede manejar la solicitud de paginaci\u00f3n del n\u00facleo en ffffa06ce6e5c058 PGD 190a01067 P4D 190a01067 PUD 43fffb067 PMD 22e403063 PTE 8000000226e5c063 Oops: 0011 [#1] SMP PTI CPU: 7 PID: 7823 Comm: kworker/7:0 Kdump: cargado Tainted: GE Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.2.1 04/01/2014 Seguimiento de llamadas: ? skb_release_head_state+0x68/0x100 ? skb_release_all+0xe/0x30 ? kfree_skb+0x32/0xa0 ? mptcp_sendmsg_frag+0x57e/0x750 ? __mptcp_retrans+0x21b/0x3c0 ? __switch_to_asm+0x35/0x70 ? mptcp_worker+0x25e/0x320 ? process_one_work+0x1a7/0x360 ? worker_thread+0x30/0x390 ? create_worker+0x1a0/0x1a0 ? kthread+0x112/0x130 ? kthread_flush_work_fn+0x10/0x10 ? ret_from_fork+0x35/0x40\n=========================================================================== En __mptcp_alloc_tx_skb, se asign\u00f3 skb y se inicializar\u00e1 skb->tcp_tsorted_anchor. En una situaci\u00f3n de presi\u00f3n de memoria insuficiente, sk_wmem_schedule devolver\u00e1 falso y luego kfree_skb. En este caso, skb->_skb_refdst no es nulo porque _skb_refdst y tcp_tsorted_anchor est\u00e1n almacenados en la misma memoria y kfree_skb intentar\u00e1 liberar dst y provocar\u00e1 un bloqueo."