CVE-2021-47130
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: nvmet: fix freeing unallocated p2pmem In case p2p device was found but the p2p pool is empty, the nvme target is still trying to free the sgl from the p2p pool instead of the regular sgl pool and causing a crash (BUG() is called). Instead, assign the p2p_dev for the request only if it was allocated from p2p pool. This is the crash that was caused: [Sun May 30 19:13:53 2021] ------------[ cut here ]------------ [Sun May 30 19:13:53 2021] kernel BUG at lib/genalloc.c:518! [Sun May 30 19:13:53 2021] invalid opcode: 0000 [#1] SMP PTI ... [Sun May 30 19:13:53 2021] kernel BUG at lib/genalloc.c:518! ... [Sun May 30 19:13:53 2021] RIP: 0010:gen_pool_free_owner+0xa8/0xb0 ... [Sun May 30 19:13:53 2021] Call Trace: [Sun May 30 19:13:53 2021] ------------[ cut here ]------------ [Sun May 30 19:13:53 2021] pci_free_p2pmem+0x2b/0x70 [Sun May 30 19:13:53 2021] pci_p2pmem_free_sgl+0x4f/0x80 [Sun May 30 19:13:53 2021] nvmet_req_free_sgls+0x1e/0x80 [nvmet] [Sun May 30 19:13:53 2021] kernel BUG at lib/genalloc.c:518! [Sun May 30 19:13:53 2021] nvmet_rdma_release_rsp+0x4e/0x1f0 [nvmet_rdma] [Sun May 30 19:13:53 2021] nvmet_rdma_send_done+0x1c/0x60 [nvmet_rdma]
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 | 4.4 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | High | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity
Technical Impact: Modify Memory
The use of previously freed memory may corrupt valid data, if the memory area in question has been allocated and used properly elsewhere.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If chunk consolidation occurs after the use of previously freed data, the process may crash when invalid data is used as chunk information.
Confidentiality
Technical Impact: Read Memory
Read operations on freed memory can sometimes leak sensitive information instead of causing a crash
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If malicious data is entered before chunk consolidation can take place, it may be possible to take advantage of a write-what-where primitive to execute arbitrary code. If the newly allocated data happens to hold a class, in C++ for example, various function pointers may be scattered within the heap data. If one of these function pointers is overwritten with an address to valid shellcode, execution of arbitrary code can be achieved.
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