CVE-2022-49295
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: nbd: call genl_unregister_family() first in nbd_cleanup() Otherwise there may be race between module removal and the handling of netlink command, which can lead to the oops as shown below: BUG: kernel NULL pointer dereference, address: 0000000000000098 Oops: 0002 [#1] SMP PTI CPU: 1 PID: 31299 Comm: nbd-client Tainted: G E 5.14.0-rc4 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:down_write+0x1a/0x50 Call Trace: start_creating+0x89/0x130 debugfs_create_dir+0x1b/0x130 nbd_start_device+0x13d/0x390 [nbd] nbd_genl_connect+0x42f/0x748 [nbd] genl_family_rcv_msg_doit.isra.0+0xec/0x150 genl_rcv_msg+0xe5/0x1e0 netlink_rcv_skb+0x55/0x100 genl_rcv+0x29/0x40 netlink_unicast+0x1a8/0x250 netlink_sendmsg+0x21b/0x430 ____sys_sendmsg+0x2a4/0x2d0 ___sys_sendmsg+0x81/0xc0 __sys_sendmsg+0x62/0xb0 __x64_sys_sendmsg+0x1f/0x30 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae Modules linked in: nbd(E-)
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).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 4.7 | 4.7 | 4.7 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | High | High |
| Privileges Required | Low | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart
NULL pointer dereferences usually result in the failure of the process unless exception handling (on some platforms) is available and implemented. Even when exception handling is being used, it can still be very difficult to return the software to a safe state of operation.
Integrity,Confidentiality
Technical Impact: Execute Unauthorized Code or Commands; Read Memory; Modify Memory
In rare circumstances, when NULL is equivalent to the 0x0 memory address and privileged code can access it, then writing or reading memory is possible, which may lead to code execution.
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