Vulnerabilidad en kernel de Linux (CVE-2024-50085)

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: mptcp: pm: corrección de lectura UaF en mptcp_pm_nl_rm_addr_or_subflow Syzkaller informó este splat: ===================================================================== ERROR: KASAN: slab-use-after-free en mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881 Lectura de tamaño 4 en la dirección ffff8880569ac858 por la tarea syz.1.2799/14662 CPU: 0 UID: 0 PID: 14662 Comm: syz.1.2799 No contaminado 6.12.0-rc2-syzkaller-00307-g36c254515dc6 #0 Nombre del hardware: PC estándar QEMU (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 01/04/2014 Seguimiento de llamadas: __dump_stack lib/dump_stack.c:94 [en línea] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:377 [en línea] print_report+0xc3/0x620 mm/kasan/report.c:488 kasan_report+0xd9/0x110 mm/kasan/report.c:601 mptcp_pm_nl_rm_addr_or_subflow+0xb44/0xcc0 net/mptcp/pm_netlink.c:881 mptcp_pm_nl_rm_subflow_received net/mptcp/pm_netlink.c:914 [en línea] mptcp_nl_remove_id_zero_address+0x305/0x4a0 net/mptcp/pm_netlink.c:1572 mptcp_pm_nl_del_addr_doit+0x5c9/0x770 net/mptcp/pm_netlink.c:1603 genl_family_rcv_msg_doit+0x202/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [en línea] genl_rcv_msg+0x565/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2551 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [en línea] netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901 sock_sendmsg_nosec red/socket.c:729 [en línea] __sock_sendmsg red/socket.c:744 [en línea] ____sys_sendmsg+0x9ae/0xb40 red/socket.c:2607 ___sys_sendmsg+0x135/0x1e0 red/socket.c:2661 __sys_sendmsg+0x117/0x1f0 red/socket.c:2690 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [en línea] __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fe4579 Código: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 RSP: 002b:00000000f574556c EFLAGS: 00000296 ORIG_RAX: 0000000000000172 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000020000140 RDX: 0000000000000000 RSI: 000000000000000 RDI: 000000000000000 RBP: 000000000000000 R08: 000000000000000 R09: 0000000000000000 R10: 00000000000000000 R11: 0000000000000296 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Asignado por la tarea 5387: kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [en línea] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394 kmalloc_noprof include/linux/slab.h:878 [en línea] kzalloc_noprof include/linux/slab.h:1014 [en línea] subflow_create_ctx+0x87/0x2a0 net/mptcp/subflow.c:1803 subflow_ulp_init+0xc3/0x4d0 net/mptcp/subflow.c:1956 __tcp_set_ulp net/ipv4/tcp_ulp.c:146 [en línea] tcp_set_ulp+0x326/0x7f0 net/ipv4/tcp_ulp.c:167 mptcp_subflow_create_socket+0x4ae/0x10a0 net/mptcp/subflow.c:1764 __mptcp_subflow_connect+0x3cc/0x1490 net/mptcp/subflow.c:1592 mptcp_pm_create_subflow_or_signal_addr+0xbda/0x23a0 net/mptcp/pm_netlink.c:642 mptcp_pm_nl_fully_established net/mptcp/pm_netlink.c:650 [en línea] mptcp_pm_nl_work+0x3a1/0x4f0 net/mptcp/pm_netlink.c:943 mptcp_worker+0x15a/0x1240 net/mptcp/protocol.c:2777 proceso_uno_trabajo+0x958/0x1b30 kernel/workqueue.c:3229 proceso_trabajo_programado kernel/workqueue.c:3310 [en línea] worker_thread+0x6c8/0xf00 kernel/workqueue.c:3391 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/ke ---truncado---