U.S. flag   An official website of the United States government
Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS
A lock (Dot gov) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

NOTICE UPDATED - May, 29th 2024

The NVD has a new announcement page with status updates, news, and how to stay connected!

CVE-2021-47572 Detail

Description

In the Linux kernel, the following vulnerability has been resolved: net: nexthop: fix null pointer dereference when IPv6 is not enabled When we try to add an IPv6 nexthop and IPv6 is not enabled (!CONFIG_IPV6) we'll hit a NULL pointer dereference[1] in the error path of nh_create_ipv6() due to calling ipv6_stub->fib6_nh_release. The bug has been present since the beginning of IPv6 nexthop gateway support. Commit 1aefd3de7bc6 ("ipv6: Add fib6_nh_init and release to stubs") tells us that only fib6_nh_init has a dummy stub because fib6_nh_release should not be called if fib6_nh_init returns an error, but the commit below added a call to ipv6_stub->fib6_nh_release in its error path. To fix it return the dummy stub's -EAFNOSUPPORT error directly without calling ipv6_stub->fib6_nh_release in nh_create_ipv6()'s error path. [1] Output is a bit truncated, but it clearly shows the error. BUG: kernel NULL pointer dereference, address: 000000000000000000 #PF: supervisor instruction fetch in kernel modede #PF: error_code(0x0010) - not-present pagege PGD 0 P4D 0 Oops: 0010 [#1] PREEMPT SMP NOPTI CPU: 4 PID: 638 Comm: ip Kdump: loaded Not tainted 5.16.0-rc1+ #446 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-4.fc34 04/01/2014 RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffff888109f5b8f0 EFLAGS: 00010286^Ac RAX: 0000000000000000 RBX: ffff888109f5ba28 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8881008a2860 RBP: ffff888109f5b9d8 R08: 0000000000000000 R09: 0000000000000000 R10: ffff888109f5b978 R11: ffff888109f5b948 R12: 00000000ffffff9f R13: ffff8881008a2a80 R14: ffff8881008a2860 R15: ffff8881008a2840 FS: 00007f98de70f100(0000) GS:ffff88822bf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000100efc000 CR4: 00000000000006e0 Call Trace: <TASK> nh_create_ipv6+0xed/0x10c rtm_new_nexthop+0x6d7/0x13f3 ? check_preemption_disabled+0x3d/0xf2 ? lock_is_held_type+0xbe/0xfd rtnetlink_rcv_msg+0x23f/0x26a ? check_preemption_disabled+0x3d/0xf2 ? rtnl_calcit.isra.0+0x147/0x147 netlink_rcv_skb+0x61/0xb2 netlink_unicast+0x100/0x187 netlink_sendmsg+0x37f/0x3a0 ? netlink_unicast+0x187/0x187 sock_sendmsg_nosec+0x67/0x9b ____sys_sendmsg+0x19d/0x1f9 ? copy_msghdr_from_user+0x4c/0x5e ? rcu_read_lock_any_held+0x2a/0x78 ___sys_sendmsg+0x6c/0x8c ? asm_sysvec_apic_timer_interrupt+0x12/0x20 ? lockdep_hardirqs_on+0xd9/0x102 ? sockfd_lookup_light+0x69/0x99 __sys_sendmsg+0x50/0x6e do_syscall_64+0xcb/0xf2 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f98dea28914 Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b5 0f 1f 80 00 00 00 00 48 8d 05 e9 5d 0c 00 8b 00 85 c0 75 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 41 54 41 89 d4 55 48 89 f5 53 RSP: 002b:00007fff859f5e68 EFLAGS: 00000246 ORIG_RAX: 000000000000002e2e RAX: ffffffffffffffda RBX: 00000000619cb810 RCX: 00007f98dea28914 RDX: 0000000000000000 RSI: 00007fff859f5ed0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000008 R10: fffffffffffffce6 R11: 0000000000000246 R12: 0000000000000001 R13: 000055c0097ae520 R14: 000055c0097957fd R15: 00007fff859f63a0 </TASK> Modules linked in: bridge stp llc bonding virtio_net


Severity



CVSS 4.0 Severity and Metrics:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.


NVD Analysts use publicly available information to associate vector strings and CVSS scores. We also display any CVSS information provided within the CVE List from the CNA.

Note: NVD Analysts have not published a CVSS score for this CVE at this time. NVD Analysts use publicly available information at the time of analysis to associate CVSS vector strings.

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving NIST webspace. We have provided these links to other web sites because they may have information that would be of interest to you. No inferences should be drawn on account of other sites being referenced, or not, from this page. There may be other web sites that are more appropriate for your purpose. NIST does not necessarily endorse the views expressed, or concur with the facts presented on these sites. Further, NIST does not endorse any commercial products that may be mentioned on these sites. Please address comments about this page to nvd@nist.gov.

Hyperlink Resource
https://git.kernel.org/stable/c/1c743127cc54b112b155f434756bd4b5fa565a99 Patch 
https://git.kernel.org/stable/c/39509d76a9a3d02f379d52cb4b1449469c56c0e0 Patch 
https://git.kernel.org/stable/c/7b6f44856da5ba0b1aa61403eb9fddd272156503 Patch 
https://git.kernel.org/stable/c/b70ff391deeec35cdd8a05f5f63f5fe28bc4f225 Patch 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-476 NULL Pointer Dereference cwe source acceptance level NIST  

Known Affected Software Configurations Switch to CPE 2.2

CPEs loading, please wait.

Denotes Vulnerable Software
Are we missing a CPE here? Please let us know.

Change History

3 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2021-47572
NVD Published Date:
05/24/2024
NVD Last Modified:
06/10/2024
Source:
kernel.org