CVE-2024-26641

ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv()

Severity Score

5.5

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

Track

*SSVC

Descriptions

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

ip6_tunnel: make sure to pull inner header in __ip6_tnl_rcv()

syzbot found __ip6_tnl_rcv() could access unitiliazed data [1].

Call pskb_inet_may_pull() to fix this, and initialize ipv6h
variable after this call as it can change skb->head.

[1]
BUG: KMSAN: uninit-value in __INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
BUG: KMSAN: uninit-value in INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
BUG: KMSAN: uninit-value in IP6_ECN_decapsulate+0x7df/0x1e50 include/net/inet_ecn.h:321
__INET_ECN_decapsulate include/net/inet_ecn.h:253 [inline]
INET_ECN_decapsulate include/net/inet_ecn.h:275 [inline]
IP6_ECN_decapsulate+0x7df/0x1e50 include/net/inet_ecn.h:321
ip6ip6_dscp_ecn_decapsulate+0x178/0x1b0 net/ipv6/ip6_tunnel.c:727
__ip6_tnl_rcv+0xd4e/0x1590 net/ipv6/ip6_tunnel.c:845
ip6_tnl_rcv+0xce/0x100 net/ipv6/ip6_tunnel.c:888
gre_rcv+0x143f/0x1870
ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438
ip6_input_finish net/ipv6/ip6_input.c:483 [inline]
NF_HOOK include/linux/netfilter.h:314 [inline]
ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492
ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586
dst_input include/net/dst.h:461 [inline]
ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79
NF_HOOK include/linux/netfilter.h:314 [inline]
ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310
__netif_receive_skb_one_core net/core/dev.c:5532 [inline]
__netif_receive_skb+0x1a6/0x5a0 net/core/dev.c:5646
netif_receive_skb_internal net/core/dev.c:5732 [inline]
netif_receive_skb+0x58/0x660 net/core/dev.c:5791
tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555
tun_get_user+0x53af/0x66d0 drivers/net/tun.c:2002
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
call_write_iter include/linux/fs.h:2084 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0x786/0x1200 fs/read_write.c:590
ksys_write+0x20f/0x4c0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x93/0xd0 fs/read_write.c:652
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

Uninit was created at:
slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
slab_alloc_node mm/slub.c:3478 [inline]
kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523
kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560
__alloc_skb+0x318/0x740 net/core/skbuff.c:651
alloc_skb include/linux/skbuff.h:1286 [inline]
alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334
sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2787
tun_alloc_skb drivers/net/tun.c:1531 [inline]
tun_get_user+0x1e8a/0x66d0 drivers/net/tun.c:1846
tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
call_write_iter include/linux/fs.h:2084 [inline]
new_sync_write fs/read_write.c:497 [inline]
vfs_write+0x786/0x1200 fs/read_write.c:590
ksys_write+0x20f/0x4c0 fs/read_write.c:643
__do_sys_write fs/read_write.c:655 [inline]
__se_sys_write fs/read_write.c:652 [inline]
__x64_sys_write+0x93/0xd0 fs/read_write.c:652
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x63/0x6b

CPU: 0 PID: 5034 Comm: syz-executor331 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: ip6_tunnel: asegúrese de extraer el encabezado interno en __ip6_tnl_rcv(). El syzbot encontró que __ip6_tnl_rcv() podía acceder a datos unificados [1]. Llame a pskb_inet_may_pull() para solucionar este problema e inicialice la variable ipv6h después de esta llamada, ya que puede cambiar skb->head. [1] ERROR: KMSAN: valor uninit en __INET_ECN_decapsulate include/net/inet_ecn.h:253 [en línea] ERROR: KMSAN: valor uninit en INET_ECN_decapsulate include/net/inet_ecn.h:275 [en línea] ERROR: KMSAN: uninit -valor en IP6_ECN_decapsulate+0x7df/0x1e50 include/net/inet_ecn.h:321 __INET_ECN_decapsulate include/net/inet_ecn.h:253 [en línea] INET_ECN_decapsulate include/net/inet_ecn.h:275 [en línea] IP6_ECN_decapsulate+0x7df/0x1e50 include/ net/inet_ecn.h:321 ip6ip6_dscp_ecn_decapsulate+0x178/0x1b0 net/ipv6/ip6_tunnel.c:727 __ip6_tnl_rcv+0xd4e/0x1590 net/ipv6/ip6_tunnel.c:845 ip6_tnl_rcv+0xce/0x100 net/ipv 6/ip6_tunnel.c:888 gre_rcv +0x143f/0x1870 ip6_protocol_deliver_rcu+0xda6/0x2a60 net/ipv6/ip6_input.c:438 ip6_input_finish net/ipv6/ip6_input.c:483 [en línea] NF_HOOK include/linux/netfilter.h:314 [en línea] ip6_input+0x15d/0x 430 netos /ipv6/ip6_input.c:492 ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586 dst_input include/net/dst.h:461 [en línea] ip6_rcv_finish+0x5db/0x870 net/ipv6/ip6_input.c:79 NF_HOOK include/linux/netfilter.h:314 [en línea] ipv6_rcv+0xda/0x390 net/ipv6/ip6_input.c:310 __netif_receive_skb_one_core net/core/dev.c:5532 [en línea] __netif_receive_skb+0x1a6/0x5a0 net/core/dev. c:5646 netif_receive_skb_internal net/core/dev.c:5732 [en línea] netif_receive_skb+0x58/0x660 net/core/dev.c:5791 tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1555 tun_get_user+0x53af/0x66d0 drivers /net/tun.c:2002 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2084 [en línea] new_sync_write fs/read_write.c:497 [en línea] vfs_write+0x786/ 0x1200 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [en línea] __se_sys_write fs/read_write.c:652 [en línea] __x64_sys_write+0x93/0xd0 fs/read _escribir .c:652 do_syscall_x64 arch/x86/entry/common.c:52 [en línea] do_syscall_64+0x6d/0x140 arch/x86/entry/common.c:83 Entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit se creó en: slab_post_alloc_hook+0x129/0xa 70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [en línea] kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560 __alloc_skb+0x318/0x740 net /core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1286 [en línea] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2787 tun_alloc_skb drivers/net/tun.c:1531 [en línea] tun_get_user+0x1e8a/0x66d0 drivers/net/tun.c:1846 tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048 call_write_iter include/linux/fs.h:2084 [en línea] new_sync_write fs/read_write.c:497 [en línea] vfs_write+0x786/0x1200 fs/read_write.c:590 ksys_write+0x20f/0x4c0 fs/read_write.c:643 __do_sys_write fs/read_write.c:655 [en línea] __se_sys_write fs/read_write.c:652 [en línea] __x64_sys_write+0x93/0xd0 fs/read_write.c:652 do_syscall_x64 arch/x86/entry/common.c:52 [en línea] do_syscall_64+0x6d/0x140 arch/x86/entry/common. c:83 Entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 0 PID: 5034 Comm: syz-executor331 No contaminado 6.7.0-syzkaller-00562-g9f8413c4a66f #0 Nombre del hardware: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/ 2023

*Credits: N/A

CVSS Scores

Red Hatv3.1 5.5

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

Tech. Impact

Partial

* Organization's Worst-case Scenario

Timeline

2024-02-19 CVE Reserved
2024-03-18 CVE Published
2024-03-19 EPSS Updated
2024-12-19 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-20: Improper Input Validation

CAPEC

References (10)

URL	Tag	Source
https://git.kernel.org/stable/c/0d3c703a9d1723c7707e0680019ac8ff5922db42	Vuln. Introduced
https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html

URL	Date	SRC

URL	Date	SRC
https://git.kernel.org/stable/c/a9bc32879a08f23cdb80a48c738017e39aea1080	2024-02-23
https://git.kernel.org/stable/c/af6b5c50d47ab43e5272ad61935d0ed2e264d3f0	2024-02-23
https://git.kernel.org/stable/c/d54e4da98bbfa8c257bdca94c49652d81d18a4d8	2024-02-05
https://git.kernel.org/stable/c/350a6640fac4b53564ec20aa3f4a0922cb0ba5e6	2024-02-05
https://git.kernel.org/stable/c/c835df3bcc14858ae9b27315dd7de76370b94f3a	2024-02-05
https://git.kernel.org/stable/c/8d975c15c0cd744000ca386247432d57b21f9df0	2024-01-26

URL	Date	SRC
https://access.redhat.com/security/cve/CVE-2024-26641	2024-11-12
https://bugzilla.redhat.com/show_bug.cgi?id=2270097	2024-11-12

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"				>= 4.7 < 5.10.210 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 5.10.210"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.7 < 5.15.149 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 5.15.149"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.7 < 6.1.77 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 6.1.77"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.7 < 6.6.16 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 6.6.16"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.7 < 6.7.4 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 6.7.4"		en		Affected
Linux Search vendor "Linux"		Linux Kernel Search vendor "Linux" for product "Linux Kernel"				>= 4.7 < 6.8 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.7 < 6.8"		en		Affected