Vulnerabilidad en kernel de Linux (CVE-2024-35899)

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: netfilter: nf_tables: vaciado pendiente de destrucción antes del lanzamiento de exit_net. Similar a 2c9f0293280e ("netfilter: nf_tables: vaciado pendiente de destrucción antes del notificador netlink") para abordar una carrera entre exit_net y destroy cola de trabajo. El siguiente seguimiento muestra un elemento que se liberará mediante la destrucción de la cola de trabajo, mientras que la ruta exit_net (activada mediante la eliminación del módulo) ya ha liberado el conjunto que se utiliza en dicha transacción. [1360.547789] ERROR: KASAN: slab-use-after-free en nf_tables_trans_destroy_work+0x3f5/0x590 [nf_tables] [1360.547861] Lectura de tamaño 8 en la dirección ffff888140500cc0 por tarea kworker/4:1/152465 [1360. 547870] CPU: 4 PID: 152465 Comm: kworker/4:1 No contaminado 6.8.0+ #359 [ 1360.547882] Cola de trabajo: eventos nf_tables_trans_destroy_work [nf_tables] [ 1360.547984] Seguimiento de llamadas: [ 1360.547991] [ 1360.547998] stack_lvl+0x53/0x70 [ 1360.548014] print_report +0xc4/0x610 [1360.548026] ? __virt_addr_valid+0xba/0x160 [1360.548040]? __pfx__raw_spin_lock_irqsave+0x10/0x10 [1360.548054]? nf_tables_trans_destroy_work+0x3f5/0x590 [nf_tables] [ 1360.548176] kasan_report+0xae/0xe0 [ 1360.548189] ? nf_tables_trans_destroy_work+0x3f5/0x590 [nf_tables] [1360.548312] nf_tables_trans_destroy_work+0x3f5/0x590 [nf_tables] [1360.548447] ? __pfx_nf_tables_trans_destroy_work+0x10/0x10 [nf_tables] [1360.548577]? _raw_spin_unlock_irq+0x18/0x30 [ 1360.548591] Process_one_work+0x2f1/0x670 [ 1360.548610] worker_thread+0x4d3/0x760 [ 1360.548627] ? __pfx_worker_thread+0x10/0x10 [ 1360.548640] kthread+0x16b/0x1b0 [ 1360.548653] ? __pfx_kthread+0x10/0x10 [ 1360.548665] ret_from_fork+0x2f/0x50 [ 1360.548679] ? __pfx_kthread+0x10/0x10 [ 1360.548690] ret_from_fork_asm+0x1a/0x30 [ 1360.548707] [ 1360.548719] Asignado por tarea 192061: [ 1360.548726] x20/0x40 [ 1360.548739] kasan_save_track+0x14/0x30 [ 1360.548750] __kasan_kmalloc+0x8f /0xa0 [ 1360.548760] __kmalloc_node+0x1f1/0x450 [ 1360.548771] nf_tables_newset+0x10c7/0x1b50 [nf_tables] [ 1360.548883] nfnetlink_rcv_batch+0xbc4/0xdc0 ] [ 1360.548909] nfnetlink_rcv+0x1a8/0x1e0 [nfnetlink] [ 1360.548927] netlink_unicast+0x367/ 0x4f0 [ 1360.548935] netlink_sendmsg+0x34b/0x610 [ 1360.548944] ____sys_sendmsg+0x4d4/0x510 [ 1360.548953] ___sys_sendmsg+0xc9/0x120 [ 1360.5489 61] __sys_sendmsg+0xbe/0x140 [ 1360.548971] do_syscall_64+0x55/0x120 [ 1360.548982] Entry_SYSCALL_64_after_hwframe+0x55/0x5d [ 1360.548994] Liberado por la tarea 192222: [ 1360.548999] kasan_save_stack+0x20/0x40 [ 1360.549009] kasan_save_track+0x14/0x30 [ 1360.549019] kasan_save_free_info+0x3b/0x60 [ 1360.549028] poison_slab_object+0x100/0x180 [ 1360.549036] __kasan_slab_free+0x14/0x30 [ 1360.549042] kfree+0xb6/0x260 [ 1360.549049] __nft_release_table+0x473/0x6a0 [nf_tables] [ 1360.549131] nf_tables_exit_net+0x170/0x240 [nf_tables] [ 1360.549221] ops_exit_list+0x5 0/0xa0 [ 1360.549229] free_exit_list+0x101/0x140 [ 1360.549236] operaciones_unregister_pernet+0x107/ 0x160 [ 1360.549245] unregister_pernet_subsys+0x1c/0x30 [ 1360.549254] nf_tables_module_exit+0x43/0x80 [nf_tables] [ 1360.549345] [ 1360.549352] do_syscall_64+0x55/0x120 [ 1360.549360] Entry_SYSCALL_64_after_hwframe+0x55/0x5d (gdb) lista *__nft_release_table +0x473 0x1e033 está en __nft_release_table (net/netfilter/nf_tables_api.c:11354). 11349 list_for_each_entry_safe(flowtable, nf, &table->flowtables, lista) { 11350 list_del(&flowtable->list); 11351 nft_use_dec(&table->use); 11352 nf_tables_flowtable_destroy(tabla de flujo); 11353 } 11354 list_for_each_entry_safe(set, ns, &table->sets, list) { 11355 list_del(&set->list); 11356 nft_use_dec(&table->use); 11357 if (set->flags & (NFT_SET_MAP | NFT_SET_OBJECT)) 11358 nft_map_deactivat ---truncado---