IM
IronMonkey Threat Research

CVE-2024-40905 MEDIUM

Published: 2024-07-12 | Last Modified: 2026-05-12 | Status: Modified

Description

In the Linux kernel, the following vulnerability has been resolved: ipv6: fix possible race in __fib6_drop_pcpu_from() syzbot found a race in __fib6_drop_pcpu_from() [1] If compiler reads more than once (*ppcpu_rt), second read could read NULL, if another cpu clears the value in rt6_get_pcpu_route(). Add a READ_ONCE() to prevent this race. Also add rcu_read_lock()/rcu_read_unlock() because we rely on RCU protection while dereferencing pcpu_rt. [1] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref in range [0x0000000000000090-0x0000000000000097] CPU: 0 PID: 7543 Comm: kworker/u8:17 Not tainted 6.10.0-rc1-syzkaller-00013-g2bfcfd584ff5 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024 Workqueue: netns cleanup_net RIP: 0010:__fib6_drop_pcpu_from.part.0+0x10a/0x370 net/ipv6/ip6_fib.c:984 Code: f8 48 c1 e8 03 80 3c 28 00 0f 85 16 02 00 00 4d 8b 3f 4d 85 ff 74 31 e8 74 a7 fa f7 49 8d bf 90 00 00 00 48 89 f8 48 c1 e8 03 <80> 3c 28 00 0f 85 1e 02 00 00 49 8b 87 90 00 00 00 48 8b 0c 24 48 RSP: 0018:ffffc900040df070 EFLAGS: 00010206 RAX: 0000000000000012 RBX: 0000000000000001 RCX: ffffffff89932e16 RDX: ffff888049dd1e00 RSI: ffffffff89932d7c RDI: 0000000000000091 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000007 R10: 0000000000000001 R11: 0000000000000006 R12: ffff88807fa080b8 R13: fffffbfff1a9a07d R14: ffffed100ff41022 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32c26000 CR3: 000000005d56e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __fib6_drop_pcpu_from net/ipv6/ip6_fib.c:966 [inline] fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1027 [inline] fib6_purge_rt+0x7f2/0x9f0 net/ipv6/ip6_fib.c:1038 fib6_del_route net/ipv6/ip6_fib.c:1998 [inline] fib6_del+0xa70/0x17b0 net/ipv6/ip6_fib.c:2043 fib6_clean_node+0x426/0x5b0 net/ipv6/ip6_fib.c:2205 fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2127 fib6_walk+0x182/0x370 net/ipv6/ip6_fib.c:2175 fib6_clean_tree+0xd7/0x120 net/ipv6/ip6_fib.c:2255 __fib6_clean_all+0x100/0x2d0 net/ipv6/ip6_fib.c:2271 rt6_sync_down_dev net/ipv6/route.c:4906 [inline] rt6_disable_ip+0x7ed/0xa00 net/ipv6/route.c:4911 addrconf_ifdown.isra.0+0x117/0x1b40 net/ipv6/addrconf.c:3855 addrconf_notify+0x223/0x19e0 net/ipv6/addrconf.c:3778 notifier_call_chain+0xb9/0x410 kernel/notifier.c:93 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992 call_netdevice_notifiers_extack net/core/dev.c:2030 [inline] call_netdevice_notifiers net/core/dev.c:2044 [inline] dev_close_many+0x333/0x6a0 net/core/dev.c:1585 unregister_netdevice_many_notify+0x46d/0x19f0 net/core/dev.c:11193 unregister_netdevice_many net/core/dev.c:11276 [inline] default_device_exit_batch+0x85b/0xae0 net/core/dev.c:11759 ops_exit_list+0x128/0x180 net/core/net_namespace.c:178 cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640 process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231 process_scheduled_works kernel/workqueue.c:3312 [inline] worker_thread+0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Additional Descriptions (1)

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ipv6: corrige posible ejecución en __fib6_drop_pcpu_from() syzbot encontró una ejecución en __fib6_drop_pcpu_from() [1] Si el compilador lee más de una vez (*ppcpu_rt), la segunda lectura podría leer NULL, si otra CPU borra el valor en rt6_get_pcpu_route(). Agregue un READ_ONCE() para evitar esta ejecución. Agregue también rcu_read_lock()/rcu_read_unlock() porque confiamos en la protección de RCU al eliminar la referencia a pcpu_rt. [1] Ups: falla de protección general, probablemente para la dirección no canónica 0xdffffc0000000012: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref en el rango [0x0000000000000090-0x0000000000000097] CPU: 0 PID: 7543 Comm: trabajador/ u8:17 No contaminado 6.10.0-rc1-syzkaller-00013-g2bfcfd584ff5 #0 Nombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/04/2024 Cola de trabajo: netns cleanup_net RIP: 0010:__fib6_drop_pcpu_from.part.0 +0x10a/0x370 net/ipv6/ip6_fib.c:984 Código: f8 48 c1 e8 03 80 3c 28 00 0f 85 16 02 00 00 4d 8b 3f 4d 85 ff 74 31 e8 74 a7 fa f7 49 8d bf 90 00 00 48 89 f8 48 c1 e8 03 &lt;80&gt; 3c 28 00 0f 85 1e 02 00 00 49 8b 87 90 00 00 00 48 8b 0c 24 48 RSP: 0018:ffffc900040df070 EFLAGS: 00010206 X: 0000000000000012 RBX: 0000000000000001 RCX: ffffffff89932e16 RDX: ffff888049dd1e00 RSI: ffffffff89932d7c RDI: 0000000000000091 RBP: dffffc0000000000 R08: 0000000000000005 R09: 0000000000000007 R10: 0000001 R11: 0000000000000006 R12: ffff88807fa080b8 R13: ffffbfff1a9a07d R14: ffffed100ff41022 R15: 0000000000000001 FS: 0000000000000000(00 00) GS:ffff8880b9200000(0000) knlGS:0000000000000000CS : 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001B32C26000 CR3: 000000005D56E000 CR4: 00000000003526F0 DR0: 00000000000000000000000000000000000000000000000000000000SET 0000000000FFFE0FF0 DR7: 000000000000000400 TRACE DE LLAMADA: __fib6_drop_pcpu_from net/ipv6/ip6_fib .c:966 [en línea] fib6_drop_pcpu_from net/ipv6/ip6_fib.c:1027 [en línea] fib6_purge_rt+0x7f2/0x9f0 net/ipv6/ip6_fib.c:1038 fib6_del_route net/ipv6/ip6_fib.c:1998 [en línea] fib6_del+0xa70 /0x17b0 net/ipv6/ip6_fib.c:2043 fib6_clean_node+0x426/0x5b0 net/ipv6/ip6_fib.c:2205 fib6_walk_continue+0x44f/0x8d0 net/ipv6/ip6_fib.c:2127 fib6_walk+0x182/0x370 /ip6_fib. c:2175 fib6_clean_tree+0xd7/0x120 net/ipv6/ip6_fib.c:2255 __fib6_clean_all+0x100/0x2d0 net/ipv6/ip6_fib.c:2271 rt6_sync_down_dev net/ipv6/route.c:4906 [en línea] /0xa00 neto /ipv6/route.c:4911 addrconf_ifdown.isra.0+0x117/0x1b40 net/ipv6/addrconf.c:3855 addrconf_notify+0x223/0x19e0 net/ipv6/addrconf.c:3778 notifier_call_chain+0xb9/0x410 kernel/notifier.c :93 call_netdevice_notifiers_info+0xbe/0x140 net/core/dev.c:1992 call_netdevice_notifiers_extack net/core/dev.c:2030 [en línea] call_netdevice_notifiers net/core/dev.c:2044 [en línea] dev_close_many+0x333/0x6a0 net/core /dev.c:1585 unregister_netdevice_many_notify+0x46d/0x19f0 net/core/dev.c:11193 unregister_netdevice_many net/core/dev.c:11276 [en línea] default_device_exit_batch+0x85b/0xae0 net/core/dev.c:11759 ops_exit_list+0x 128 /0x180 net/core/net_namespace.c:178 cleanup_net+0x5b7/0xbf0 net/core/net_namespace.c:640 Process_one_work+0x9fb/0x1b60 kernel/workqueue.c:3231 Process_scheduled_works kernel/workqueue.c:3312 [en línea] work_thread+ 0x6c8/0xf70 kernel/workqueue.c:3393 kthread+0x2c1/0x3a0 kernel/kthread.c:389 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64 .S:244

CVSS Metrics

Base Score: 4.7 (MEDIUM)

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Attack VectorLOCAL
Attack ComplexityHIGH
Privileges RequiredLOW
User InteractionNONE
ScopeUNCHANGED
Confidentiality ImpactNONE
Integrity ImpactNONE
Availability ImpactHIGH

Source: [email protected]

Type: Primary

Exploitability Score: 1.0

Impact Score: 3.6

Weaknesses

Source Type Description
[email protected] Primary
en CWE-476

Affected Products

Vendor Product Version Update Type
linux linux_kernel * <built-in method update of dict object at 0x7fd38499f940> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd3686e58c0> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd2d39fd800> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd3695ad340> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd3408f6b80> Operating System
linux linux_kernel * <built-in method update of dict object at 0x7fd3408f5900> Operating System
linux linux_kernel 6.10 <built-in method update of dict object at 0x7fd3686e7a80> Operating System
linux linux_kernel 6.10 <built-in method update of dict object at 0x7fd369ad06c0> Operating System

Affected Configurations

Operator: OR

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:6.10:rc1:*:*:*:*:*:*
Yes cpe:2.3:o:linux:linux_kernel:6.10:rc2:*:*:*:*:*:*

References