// For flags

CVE-2024-36902

ipv6: fib6_rules: avoid possible NULL dereference in fib6_rule_action()

Severity Score

5.5
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved:

ipv6: fib6_rules: avoid possible NULL dereference in fib6_rule_action()

syzbot is able to trigger the following crash [1],
caused by unsafe ip6_dst_idev() use.

Indeed ip6_dst_idev() can return NULL, and must always be checked.

[1]

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 31648 Comm: syz-executor.0 Not tainted 6.9.0-rc4-next-20240417-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
RIP: 0010:__fib6_rule_action net/ipv6/fib6_rules.c:237 [inline]
RIP: 0010:fib6_rule_action+0x241/0x7b0 net/ipv6/fib6_rules.c:267
Code: 02 00 00 49 8d 9f d8 00 00 00 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 f9 32 bf f7 48 8b 1b 48 89 d8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 df e8 e0 32 bf f7 4c 8b 03 48 89 ef 4c
RSP: 0018:ffffc9000fc1f2f0 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 1a772f98c8186700
RDX: 0000000000000003 RSI: ffffffff8bcac4e0 RDI: ffffffff8c1f9760
RBP: ffff8880673fb980 R08: ffffffff8fac15ef R09: 1ffffffff1f582bd
R10: dffffc0000000000 R11: fffffbfff1f582be R12: dffffc0000000000
R13: 0000000000000080 R14: ffff888076509000 R15: ffff88807a029a00
FS: 00007f55e82ca6c0(0000) GS:ffff8880b9400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b31d23000 CR3: 0000000022b66000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
fib_rules_lookup+0x62c/0xdb0 net/core/fib_rules.c:317
fib6_rule_lookup+0x1fd/0x790 net/ipv6/fib6_rules.c:108
ip6_route_output_flags_noref net/ipv6/route.c:2637 [inline]
ip6_route_output_flags+0x38e/0x610 net/ipv6/route.c:2649
ip6_route_output include/net/ip6_route.h:93 [inline]
ip6_dst_lookup_tail+0x189/0x11a0 net/ipv6/ip6_output.c:1120
ip6_dst_lookup_flow+0xb9/0x180 net/ipv6/ip6_output.c:1250
sctp_v6_get_dst+0x792/0x1e20 net/sctp/ipv6.c:326
sctp_transport_route+0x12c/0x2e0 net/sctp/transport.c:455
sctp_assoc_add_peer+0x614/0x15c0 net/sctp/associola.c:662
sctp_connect_new_asoc+0x31d/0x6c0 net/sctp/socket.c:1099
__sctp_connect+0x66d/0xe30 net/sctp/socket.c:1197
sctp_connect net/sctp/socket.c:4819 [inline]
sctp_inet_connect+0x149/0x1f0 net/sctp/socket.c:4834
__sys_connect_file net/socket.c:2048 [inline]
__sys_connect+0x2df/0x310 net/socket.c:2065
__do_sys_connect net/socket.c:2075 [inline]
__se_sys_connect net/socket.c:2072 [inline]
__x64_sys_connect+0x7a/0x90 net/socket.c:2072
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: ipv6: fib6_rules: evita una posible desreferencia NULL en fib6_rule_action() syzbot es capaz de desencadenar el siguiente bloqueo [1], causado por el uso inseguro de ip6_dst_idev(). De hecho, ip6_dst_idev() puede devolver NULL y siempre debe verificarse. [1] Vaya: fallo de protección general, probablemente para la dirección no canónica 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN PTI KASAN: null-ptr-deref en el rango [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 31648 Comm : syz- executor.0 No contaminado 6.9.0-rc4-next-20240417-syzkaller #0 Nombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 27/03/2024 RIP: 0010:__fib6_rule_action net/ipv6/fib6_rules.c: 237 [en línea] RIP: 0010:fib6_rule_action+0x241/0x7b0 net/ipv6/fib6_rules.c:267 Código: 02 00 00 49 8d 9f d8 00 00 00 48 89 d8 48 c1 e8 03 42 80 3c 20 00 74 08 48 89 df e8 f9 32 bf f7 48 8b 1b 48 89 d8 48 c1 e8 03 &lt;42&gt; 80 3c 20 00 74 08 48 89 df e8 e0 32 bf f7 4c 8b 03 48 89 ef 4c RSP:ffffc9000fc1f2f 0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000000000000000 RCX: 1a772f98c8186700 RDX: 0000000000000003 RSI: ffffffff8bcac4e0 RDI: ffffffff8c1f9760 RBP: ffff8880673f b980 R08: ffffffff8fac15ef R09: 1ffffffff1f582bd R10: dffffc0000000000 R11: ffffbfff1f582be R12: dffffc0000000000 R13: 0000000000000080 R14: ffff88807650 9000 R15: ffff88807a029a00 FS: 00007f55e82ca6c0(0000) GS :ffff8880b9400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b31d23000 CR3: 0000000022b66000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 00000000000000000 DR6: 00000000ffe0ff0 DR7: 0000000000400 Seguimiento de llamadas: fib_rules_lookup+0x62c/0xdb0 net/core/fib_rules.c:317 fib6_rule_lookup+0x1fd/0x790 net/ipv6/fib6_rules.c:108 ip6_route_output_flags_noref net/ipv6/route.c:2637 [en línea] gs+0x38e/0x610 neto /ipv6/route.c:2649 ip6_route_output include/net/ip6_route.h:93 [en línea] ip6_dst_lookup_tail+0x189/0x11a0 net/ipv6/ip6_output.c:1120 ip6_dst_lookup_flow+0xb9/0x180 net/ipv6/ip6_output.c:1250 sctp_v6_get_dst +0x792/0x1e20 net/sctp/ipv6.c:326 sctp_transport_route+0x12c/0x2e0 net/sctp/transport.c:455 sctp_assoc_add_peer+0x614/0x15c0 net/sctp/associola.c:662 sctp_connect_new_asoc+0x31d/ 0x6c0 neto/sctp/ socket.c:1099 __sctp_connect+0x66d/0xe30 net/sctp/socket.c:1197 sctp_connect net/sctp/socket.c:4819 [en línea] sctp_inet_connect+0x149/0x1f0 net/sctp/socket.c:4834 __sys_connect_file net/socket .c:2048 [en línea] __sys_connect+0x2df/0x310 net/socket.c:2065 __do_sys_connect net/socket.c:2075 [en línea] __se_sys_connect net/socket.c:2072 [en línea] __x64_sys_connect+0x7a/0x90 net/socket. c:2072 do_syscall_x64 arch/x86/entry/common.c:52 [en línea] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 Entry_SYSCALL_64_after_hwframe+0x77/0x7f

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-05-30 CVE Reserved
  • 2024-05-30 CVE Published
  • 2024-06-11 EPSS Updated
  • 2024-11-05 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-476: NULL Pointer Dereference
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.26 < 4.19.314
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.26 < 4.19.314"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.26 < 5.4.276
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.26 < 5.4.276"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.26 < 5.10.217
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.26 < 5.10.217"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.26 < 5.15.159
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.26 < 5.15.159"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.26 < 6.1.91
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.26 < 6.1.91"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.26 < 6.6.31
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.26 < 6.6.31"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.26 < 6.8.10
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.26 < 6.8.10"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.26 < 6.9
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.26 < 6.9"
en
Affected