In the Linux kernel, the following vulnerability has been resolved: net/ipv6: avoid possible UAF in ip6_route_mpath_notify() syzbot found another use-after-free in ip6_route_mpath_notify() [1] Commit f7225172f25a ("net/ipv6: prevent use after free in ip6_route_mpath_notify") was not able to fix the root cause. We need to defer the fib6_info_release() calls after ip6_route_mpath_notify(), in the cleanup phase. [1] BUG: KASAN: slab-use-after-free in rt6_fill_node+0x1460/0x1ac0 Read of size 4 at addr ffff88809a07fc64 by task syz-executor.2/23037 CPU: 0 PID: 23037 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-01035-gea7f3cfaa588 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [inline] print_report+0x167/0x540 mm/kasan/report.c:488 kasan_report+0x142/0x180 mm/kasan/report.c:601 rt6_fill_node+0x1460/0x1ac0 inet6_rt_notify+0x13b/0x290 net/ipv6/route.c:6184 ip6_route_mpath_notify net/ipv6/route.c:5198 [inline] ip6_route_multipath_add net/ipv6/route.c:5404 [inline] inet6_rtm_newroute+0x1d0f/0x2300 net/ipv6/route.c:5517 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 RIP: 0033:0x7f73dd87dda9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f73de6550c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f73dd9ac050 RCX: 00007f73dd87dda9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 00007f73dd8ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f73dd9ac050 R15: 00007ffdbdeb7858 </TASK> Allocated by task 23037: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:372 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h:211 [inline] __do_kmalloc_node mm/slub.c:3981 [inline] __kmalloc+0x22e/0x490 mm/slub.c:3994 kmalloc include/linux/slab.h:594 [inline] kzalloc include/linux/slab.h:711 [inline] fib6_info_alloc+0x2e/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x445/0x12b0 net/ipv6/route.c:3758 ip6_route_multipath_add net/ipv6/route.c:5298 [inline] inet6_rtm_newroute+0x744/0x2300 net/ipv6/route.c:5517 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [inline] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [inline] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entry_SYSCALL_64_after_hwframe+0x6f/0x77 Freed by task 16: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x4e/0x60 mm/kasan/generic.c:640 poison_slab_object+0xa6/0xe0 m ---truncated---
En el kernel de Linux se ha resuelto la siguiente vulnerabilidad: net/ipv6: evita posible UAF en ip6_route_mpath_notify() syzbot encontró otro use-after-free en ip6_route_mpath_notify() [1] Commit f7225172f25a ("net/ipv6: previene el use-after-free in ip6_route_mpath_notify") no pudo solucionar la causa raíz. Necesitamos diferir las llamadas a fib6_info_release() después de ip6_route_mpath_notify(), en la fase de limpieza. [1] ERROR: KASAN: slab-use-after-free en rt6_fill_node+0x1460/0x1ac0 Lectura de tamaño 4 en la dirección ffff88809a07fc64 mediante la tarea syz-executor.2/23037 CPU: 0 PID: 23037 Comm: syz-executor.2 Not tainted 6.8.0-rc4-syzkaller-01035-gea7f3cfaa588 #0 Nombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 25/01/2024 Seguimiento de llamadas: __dump_stack lib/dump_stack.c:88 [en línea] dump_stack_lvl+0x1e7/0x2e0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:377 [en línea] print_report+0x167/0x540 mm/kasan/report.c:488 kasan_report+0x142/0x180 mm/kasan/report. c:601 rt6_fill_node+0x1460/0x1ac0 inet6_rt_notify+0x13b/0x290 net/ipv6/route.c:6184 ip6_route_mpath_notify net/ipv6/route.c:5198 [en línea] ip6_route_multipath_add net/ipv6/route.c:5404 et6_rtm_nuevaruta+ 0x1d0f/0x2300 net/ipv6/route.c:5517 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1 341 [en línea] netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [en línea] __sock_sendmsg+0x221/0x270 net/socket .c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [en línea] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entrada_SYSC ALL_64_after_hwframe+0x6f/0x77 RIP : 0033:0x7f73dd87dda9 Código: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 24 08 0f 05 <48 > 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f73de6550c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: de RBX: 00007f73dd9ac050 RCX: 00007f73dd87dda9 RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000005 RBP: 00007f73dd8ca47a R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000006e R14: 00007f73dd9ac050 R15: 00007ffdbdeb7858 Asignado por tarea 23037: kasan_save_stack mm/kasan/common.c:47 [en línea] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 veneno_kmalloc_redzone mm/kasan/common.c:372 [en línea] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:389 kasan_kmalloc include/linux/kasan.h: 211 [en línea] __do_kmalloc_node mm/slub.c:3981 [en línea] __kmalloc+0x22e/0x490 mm/slub.c:3994 kmalloc include/linux/slab.h:594 [en línea] kzalloc include/linux/slab.h:711 [en línea] fib6_info_alloc+0x2e/0xf0 net/ipv6/ip6_fib.c:155 ip6_route_info_create+0x445/0x12b0 net/ipv6/route.c:3758 ip6_route_multipath_add net/ipv6/route.c:5298 [inet6_rtm_newroute+0x74 4/0x2300 neto /ipv6/route.c:5517 rtnetlink_rcv_msg+0x885/0x1040 net/core/rtnetlink.c:6597 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2543 netlink_unicast_kernel net/netlink/af_netlink.c:1341 [en línea] netlink_unicast +0x7ea/0x980 net/netlink/af_netlink.c:1367 netlink_sendmsg+0xa3b/0xd70 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:730 [en línea] __sock_sendmsg+0x221/0x270 net/socket.c:745 ____sys_sendmsg+0x525/0x7d0 net/socket.c:2584 ___sys_sendmsg net/socket.c:2638 [en línea] __sys_sendmsg+0x2b0/0x3a0 net/socket.c:2667 do_syscall_64+0xf9/0x240 entrada_SYSCALL_64_after_ hwframe+0x6f/0x77 Liberado por la tarea 16: kasan_save_stack mm/kasan/common.c:47 [en línea] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x4e/0x60 mm/kasan/generic.c:640 veneno_slab_object+0xa6/0xe0 m --- truncado---
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | LOCAL |
|---|---|
| Attack Complexity | LOW |
| Privileges Required | LOW |
| User Interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality Impact | HIGH |
| Integrity Impact | HIGH |
| Availability Impact | HIGH |
Source: 134c704f-9b21-4f2e-91b3-4a467353bcc0
Type: Secondary
Exploitability Score: 1.8
Impact Score: 5.9
| Source | Type | Description |
|---|---|---|
| 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary |
en
CWE-416
|
| Vendor | Product | Version | Update | Type |
|---|---|---|---|---|
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd370195b00> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd36a7ddc80> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd3401ffc00> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd360614980> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd3401fe380> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd3401ff900> | Operating System |
| linux | linux_kernel | * | <built-in method update of dict object at 0x7fd3606158c0> | Operating System |
| linux | linux_kernel | 6.8 | <built-in method update of dict object at 0x7fd36b8d3a00> | Operating System |
| linux | linux_kernel | 6.8 | <built-in method update of dict object at 0x7fd2a1e27780> | Operating System |
| linux | linux_kernel | 6.8 | <built-in method update of dict object at 0x7fd3401fef40> | Operating System |
| linux | linux_kernel | 6.8 | <built-in method update of dict object at 0x7fd3105cb1c0> | Operating System |
| linux | linux_kernel | 6.8 | <built-in method update of dict object at 0x7fd360615880> | Operating System |
| linux | linux_kernel | 6.8 | <built-in method update of dict object at 0x7fd3686ec480> | Operating System |
| debian | debian_linux | 10.0 | <built-in method update of dict object at 0x7fd36a7dd540> | Operating System |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.8:rc1:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.8:rc2:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.8:rc3:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.8:rc4:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.8:rc5:*:*:*:*:*:* |
| Yes | cpe:2.3:o:linux:linux_kernel:6.8:rc6:*:*:*:*:*:* |
| Vulnerable | CPE |
|---|---|
| Yes | cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:* |