Bug 2426217 (CVE-2022-50869)

Summary:	CVE-2022-50869 kernel: Linux kernel: Arbitrary code execution via slab-out-of-bounds in ntfs3
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's `fs/ntfs3` component. This memory corruption vulnerability, specifically a slab-out-of-bounds error, occurs when the `read_log_page` function attempts to copy data into a buffer that is smaller than the data being written. An attacker could potentially exploit this flaw to cause a denial of service or achieve arbitrary code execution.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-12-30 13:17:11 UTC

In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: Fix slab-out-of-bounds in r_page

When PAGE_SIZE is 64K, if read_log_page is called by log_read_rst for
the first time, the size of *buffer would be equal to
DefaultLogPageSize(4K).But for *buffer operations like memcpy,
if the memory area size(n) which being assigned to buffer is larger
than 4K (log->page_size(64K) or bytes(64K-page_off)), it will cause
an out of boundary error.
 Call trace:
  [...]
  kasan_report+0x44/0x130
  check_memory_region+0xf8/0x1a0
  memcpy+0xc8/0x100
  ntfs_read_run_nb+0x20c/0x460
  read_log_page+0xd0/0x1f4
  log_read_rst+0x110/0x75c
  log_replay+0x1e8/0x4aa0
  ntfs_loadlog_and_replay+0x290/0x2d0
  ntfs_fill_super+0x508/0xec0
  get_tree_bdev+0x1fc/0x34c
  [...]

Fix this by setting variable r_page to NULL in log_read_rst.

Comment 1 Alexander B 2025-12-31 00:39:00 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025123050-CVE-2022-50869-8a8f@gregkh/T