"value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: do not leave a dangling sk pointer, when socket creation fails\n\nIt is possible to trigger a use-after-free by:\n * attaching an fentry probe to __sock_release() and the probe calling the\n bpf_get_socket_cookie() helper\n * running traceroute -I 1.1.1.1 on a freshly booted VM\n\nA KASAN enabled kernel will log something like below (decoded and stripped):\n==================================================================\nBUG: KASAN: slab-use-after-free in __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)\nRead of size 8 at addr ffff888007110dd8 by task traceroute/299\n\nCPU: 2 PID: 299 Comm: traceroute Tainted: G E 6.10.0-rc2+ #2\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 04/01/2014\nCall Trace:\n <TASK>\ndump_stack_lvl (lib/dump_stack.c:117 (discriminator 1))\nprint_report (mm/kasan/report.c:378 mm/kasan/report.c:488)\n? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)\nkasan_report (mm/kasan/report.c:603)\n? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)\nkasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189)\n__sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29)\nbpf_get_socket_ptr_cookie (./arch/x86/include/asm/preempt.h:94 ./include/linux/sock_diag.h:42 net/core/filter.c:5094 net/core/filter.c:5092)\nbpf_prog_875642cf11f1d139___sock_release+0x6e/0x8e\nbpf_trampoline_6442506592+0x47/0xaf\n__sock_release (net/socket.c:652)\n__sock_create (net/socket.c:1601)\n...\nAllocated by task 299 on cpu 2 at 78.328492s:\nkasan_save_stack (mm/kasan/common.c:48)\nkasan_save_track (mm/kasan/common.c:68)\n__kasan_slab_alloc (mm/kasan/common.c:312 mm/kasan/common.c:338)\nkmem_cache_alloc_noprof (mm/slub.c:3941 mm/slub.c:4000 mm/slub.c:4007)\nsk_prot_alloc (net/core/sock.c:2075)\nsk_alloc (net/core/sock.c:2134)\ninet_create (net/ipv4/af_inet.c:327 net/ipv4/af_inet.c:252)\n__sock_create (net/socket.c:1572)\n__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)\n__x64_sys_socket (net/socket.c:1718)\ndo_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)\nentry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)\n\nFreed by task 299 on cpu 2 at 78.328502s:\nkasan_save_stack (mm/kasan/common.c:48)\nkasan_save_track (mm/kasan/common.c:68)\nkasan_save_free_info (mm/kasan/generic.c:582)\npoison_slab_object (mm/kasan/common.c:242)\n__kasan_slab_free (mm/kasan/common.c:256)\nkmem_cache_free (mm/slub.c:4437 mm/slub.c:4511)\n__sk_destruct (net/core/sock.c:2117 net/core/sock.c:2208)\ninet_create (net/ipv4/af_inet.c:397 net/ipv4/af_inet.c:252)\n__sock_create (net/socket.c:1572)\n__sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706)\n__x64_sys_socket (net/socket.c:1718)\ndo_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83)\nentry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)\n\nFix this by clearing the struct socket reference in sk_common_release() to cover\nall protocol families create functions, which may already attached the\nreference to the sk object with sock_init_data()."
"value":"En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: net: no deja un puntero sk colgando cuando falla la creaci\u00f3n del socket. Es posible activar un use-after-free: * adjuntando una sonda fentry a __sock_release() y el sonda que llama al asistente bpf_get_socket_cookie() * ejecuta traceroute -I 1.1.1.1 en una m\u00e1quina virtual reci\u00e9n iniciada. Un kernel habilitado para KASAN registrar\u00e1 algo como lo siguiente (decodificado y eliminado): =============== ==================================================== = ERROR: KASAN: slab-use-after-free en __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include /linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) Lectura de tama\u00f1o 8 en la direcci\u00f3n ffff888007110dd8 mediante tarea traceroute/299 CPU: 2 PID: 299 Comm: traceroute Contaminado: GE 6.10.0- rc2+ #2 Nombre del hardware: PC est\u00e1ndar QEMU (i440FX + PIIX, 1996), BIOS 1.16.2-debian-1.16.2-1 01/04/2014 Seguimiento de llamadas: dump_stack_lvl (lib/dump_stack.c:117 ( discriminador 1)) print_report (mm/kasan/report.c:378 mm/kasan/report.c:488)? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 neto /core/sock_diag.c:29) kasan_report (mm/kasan/report.c:603)? __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include/linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 neto /core/sock_diag.c:29) kasan_check_range (mm/kasan/generic.c:183 mm/kasan/generic.c:189) __sock_gen_cookie (./arch/x86/include/asm/atomic64_64.h:15 ./include /linux/atomic/atomic-arch-fallback.h:2583 ./include/linux/atomic/atomic-instrumented.h:1611 net/core/sock_diag.c:29) bpf_get_socket_ptr_cookie (./arch/x86/include/asm /preempt.h:94 ./include/linux/sock_diag.h:42 net/core/filter.c:5094 net/core/filter.c:5092) bpf_prog_875642cf11f1d139___sock_release+0x6e/0x8e bpf_trampoline_6442506592+0x47/0xaf __ calcet\u00edn_release (net/ socket.c:652) __sock_create (net/socket.c:1601) ... Asignado por la tarea 299 en la CPU 2 en 78.328492s: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common. c:68) __kasan_slab_alloc (mm/kasan/common.c:312 mm/kasan/common.c:338) kmem_cache_alloc_noprof (mm/slub.c:3941 mm/slub.c:4000 mm/slub.c:4007) sk_prot_alloc (net/core/sock.c:2075) sk_alloc (net/core/sock.c:2134) inet_create (net/ipv4/af_inet.c:327 net/ipv4/af_inet.c:252) __sock_create (net/socket. c:1572) __sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706) __x64_sys_socket (net/socket.c:1718) do_syscall_64 (arch/x86/entry/common.c: 52 arch/x86/entry/common.c:83) Entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Liberado por la tarea 299 en la CPU 2 a las 78.328502s: kasan_save_stack (mm/kasan/common.c:48) kasan_save_track (mm/kasan/common.c:68) kasan_save_free_info (mm/kasan/generic.c:582) veneno_slab_object (mm/kasan/common.c:242) __kasan_slab_free (mm/kasan/common.c:256) kmem_cache_free ( mm/slub.c:4437 mm/slub.c:4511) __sk_destruct (net/core/sock.c:2117 net/core/sock.c:2208) inet_create (net/ipv4/af_inet.c:397 net/ipv4 /af_inet.c:252) __sock_create (net/socket.c:1572) __sys_socket (net/socket.c:1660 net/socket.c:1644 net/socket.c:1706) __x64_sys_socket (net/socket.c:1718 ) do_syscall_64 (arch/x86/entry/common.c:52 arch/x86/entry/common.c:83) Entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) Solucione este problema borrando la referencia del socket de estructura en sk_common_release () para cubrir todas las familias de protocolos, cree funciones, que pueden ya adjuntar la referencia al objeto sk con sock_init_data()."
