CVE-2022-49927
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: nfs4: Fix kmemleak when allocate slot failed If one of the slot allocate failed, should cleanup all the other allocated slots, otherwise, the allocated slots will leak: unreferenced object 0xffff8881115aa100 (size 64): comm ""mount.nfs"", pid 679, jiffies 4294744957 (age 115.037s) hex dump (first 32 bytes): 00 cc 19 73 81 88 ff ff 00 a0 5a 11 81 88 ff ff ...s......Z..... 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000007a4c434a>] nfs4_find_or_create_slot+0x8e/0x130 [<000000005472a39c>] nfs4_realloc_slot_table+0x23f/0x270 [<00000000cd8ca0eb>] nfs40_init_client+0x4a/0x90 [<00000000128486db>] nfs4_init_client+0xce/0x270 [<000000008d2cacad>] nfs4_set_client+0x1a2/0x2b0 [<000000000e593b52>] nfs4_create_server+0x300/0x5f0 [<00000000e4425dd2>] nfs4_try_get_tree+0x65/0x110 [<00000000d3a6176f>] vfs_get_tree+0x41/0xf0 [<0000000016b5ad4c>] path_mount+0x9b3/0xdd0 [<00000000494cae71>] __x64_sys_mount+0x190/0x1d0 [<000000005d56bdec>] do_syscall_64+0x35/0x80 [<00000000687c9ae4>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
Statement
Memory Leak in nfs4_setup_slot_table() on Allocation Failure. In NFSv4, if slot allocation fails during the setup of a slot table, previously allocated slots are not freed, leading to a kernel memory leak. The issue occurs during NFS mount attempts and may result in unreferenced kernel memory accumulation (visible via kmemleak). Only local user with ability to invoke mount.nfs (e.g., CAP_SYS_ADMIN) can trigger this one.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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 | 2.8 | 5.5 | 5.5 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | Low | Low | Low |
| Privileges Required | Low | Low | Low |
| User Interaction | Required | None | None |
| Scope | Unchanged | Unchanged | Unchanged |
| Confidentiality | None | None | None |
| Integrity Impact | None | None | None |
| Availability Impact | Low | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:L
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Crash, Exit, or Restart; DoS: Instability; DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory)
Most memory leaks result in general product reliability problems, but if an attacker can intentionally trigger a memory leak, the attacker might be able to launch a denial of service attack (by crashing or hanging the program) or take advantage of other unexpected program behavior resulting from a low memory condition.
Other
Technical Impact: Reduce Performance
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