CVE-2024-26633

Description

From CVE.org

In the Linux kernel, the following vulnerability has been resolved: ip6_tunnel: fix NEXTHDR_FRAGMENT handling in ip6_tnl_parse_tlv_enc_lim() syzbot pointed out [1] that NEXTHDR_FRAGMENT handling is broken. Reading frag_off can only be done if we pulled enough bytes to skb->head. Currently we might access garbage. [1] BUG: KMSAN: uninit-value in ip6_tnl_parse_tlv_enc_lim+0x94f/0xbb0 ip6_tnl_parse_tlv_enc_lim+0x94f/0xbb0 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1326 [inline] ip6_tnl_start_xmit+0xab2/0x1a70 net/ipv6/ip6_tunnel.c:1432 __netdev_start_xmit include/linux/netdevice.h:4940 [inline] netdev_start_xmit include/linux/netdevice.h:4954 [inline] xmit_one net/core/dev.c:3548 [inline] dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564 __dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349 dev_queue_xmit include/linux/netdevice.h:3134 [inline] neigh_connected_output+0x569/0x660 net/core/neighbour.c:1592 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0x23a9/0x2b30 net/ipv6/ip6_output.c:137 ip6_finish_output+0x855/0x12b0 net/ipv6/ip6_output.c:222 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip6_output+0x323/0x610 net/ipv6/ip6_output.c:243 dst_output include/net/dst.h:451 [inline] ip6_local_out+0xe9/0x140 net/ipv6/output_core.c:155 ip6_send_skb net/ipv6/ip6_output.c:1952 [inline] ip6_push_pending_frames+0x1f9/0x560 net/ipv6/ip6_output.c:1972 rawv6_push_pending_frames+0xbe8/0xdf0 net/ipv6/raw.c:582 rawv6_sendmsg+0x2b66/0x2e70 net/ipv6/raw.c:920 inet_sendmsg+0x105/0x190 net/ipv4/af_inet.c:847 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg net/socket.c:2667 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 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+0x5c9/0x970 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0x118/0x3c0 mm/slab_common.c:1027 kmalloc_reserve+0x249/0x4a0 net/core/skbuff.c:582 pskb_expand_head+0x226/0x1a00 net/core/skbuff.c:2098 __pskb_pull_tail+0x13b/0x2310 net/core/skbuff.c:2655 pskb_may_pull_reason include/linux/skbuff.h:2673 [inline] pskb_may_pull include/linux/skbuff.h:2681 [inline] ip6_tnl_parse_tlv_enc_lim+0x901/0xbb0 net/ipv6/ip6_tunnel.c:408 ipxip6_tnl_xmit net/ipv6/ip6_tunnel.c:1326 [inline] ip6_tnl_start_xmit+0xab2/0x1a70 net/ipv6/ip6_tunnel.c:1432 __netdev_start_xmit include/linux/netdevice.h:4940 [inline] netdev_start_xmit include/linux/netdevice.h:4954 [inline] xmit_one net/core/dev.c:3548 [inline] dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564 __dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349 dev_queue_xmit include/linux/netdevice.h:3134 [inline] neigh_connected_output+0x569/0x660 net/core/neighbour.c:1592 neigh_output include/net/neighbour.h:542 [inline] ip6_finish_output2+0x23a9/0x2b30 net/ipv6/ip6_output.c:137 ip6_finish_output+0x855/0x12b0 net/ipv6/ip6_output.c:222 NF_HOOK_COND include/linux/netfilter.h:303 [inline] ip6_output+0x323/0x610 net/ipv6/ip6_output.c:243 dst_output include/net/dst.h:451 [inline] ip6_local_out+0xe9/0x140 net/ipv6/output_core.c:155 ip6_send_skb net/ipv6/ip6_output.c:1952 [inline] ip6_push_pending_frames+0x1f9/0x560 net/ipv6/ip6_output.c:1972 rawv6_push_pending_frames+0xbe8/0xdf0 net/ipv6/raw.c:582 rawv6_sendmsg+0x2b66/0x2e70 net/ipv6/raw.c:920 inet_sendmsg+0x105/0x190 net/ipv4/af_inet.c:847 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg net/socket.c:2667 [inline] __do_sys_sendms ---truncated---

Common Vulnerability Scoring System (CVSS) Score Details

Info alert:Important note

CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).

CVSS v3 Score Breakdown

Red HatNVDcve.org
Base Score5.5N/AN/A
Attack VectorLocalN/AN/A
Attack ComplexityLowN/AN/A
Privileges RequiredLowN/AN/A
User InteractionNoneN/AN/A
ScopeUnchangedN/AN/A
ConfidentialityNoneN/AN/A
Integrity ImpactNoneN/AN/A
Availability ImpactHighN/AN/A

Vector

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

Understanding the Weakness (CWE)

CWE-20

Availability

Technical Impact: DoS: Crash, Exit, or Restart; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)

An attacker could provide unexpected values and cause a program crash or arbitrary control of resource allocation, leading to excessive consumption of resources such as memory and CPU.

Confidentiality

Technical Impact: Read Memory; Read Files or Directories

An attacker could read confidential data if they are able to control resource references.

Integrity,Confidentiality,Availability

Technical Impact: Modify Memory; Execute Unauthorized Code or Commands

An attacker could use malicious input to modify data or possibly alter control flow in unexpected ways, including arbitrary command execution.

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