CVE-2022-49257 - Vulnerability Details

- watch_queue: Fix NULL dereference in error cleanup

Description

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

watch_queue: Fix NULL dereference in error cleanup

In watch_queue_set_size(), the error cleanup code doesn't take account of
the fact that __free_page() can't handle a NULL pointer when trying to free
up buffer pages that did get allocated.

Fix this by only calling __free_page() on the pages actually allocated.

Without the fix, this can lead to something like the following:

BUG: KASAN: null-ptr-deref in __free_pages+0x1f/0x1b0 mm/page_alloc.c:5473
Read of size 4 at addr 0000000000000034 by task syz-executor168/3599
...
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
__kasan_report mm/kasan/report.c:446 [inline]
kasan_report.cold+0x66/0xdf mm/kasan/report.c:459
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
instrument_atomic_read include/linux/instrumented.h:71 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
page_ref_count include/linux/page_ref.h:67 [inline]
put_page_testzero include/linux/mm.h:717 [inline]
__free_pages+0x1f/0x1b0 mm/page_alloc.c:5473
watch_queue_set_size+0x499/0x630 kernel/watch_queue.c:275
pipe_ioctl+0xac/0x2b0 fs/pipe.c:632
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

Published: 2025-02-26

Score: 5.5 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

Linux

unaffected

Version	Status	Constraints
`c73be61cede5882f9605a852414db559c0ebedfd`	affected	< 5ae75b4ed30322b42abaa75ef1b784addfdb7dc9
`c73be61cede5882f9605a852414db559c0ebedfd`	affected	< 695c47cea02b9101e2fc2e7d36d552128592b347
`c73be61cede5882f9605a852414db559c0ebedfd`	affected	< 112a2f9b0a8457794095a0450598f150724ec456
`c73be61cede5882f9605a852414db559c0ebedfd`	affected	< b6f5ad3e45d19f9c4ee3e8a2aff829f28d68591d
`c73be61cede5882f9605a852414db559c0ebedfd`	affected	< a635415a064e77bcfbf43da413fd9dfe0bbed9cb

Linux

affected

Version	Status	Constraints
`5.8`	affected	—
`0`	unaffected	< 5.8
`5.10.110`	unaffected	≤ 5.10.*
`5.15.33`	unaffected	≤ 5.15.*
`5.16.19`	unaffected	≤ 5.16.*
`5.17.2`	unaffected	≤ 5.17.*
`5.18`	unaffected	≤ *

Configuration 1 [-]

OR	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::
	cpe:2.3:o:linux:linux_kernel::::::::

Package	CPE	Advisory	Released Date
Red Hat Enterprise Linux 9
kernel-0:5.14.0-362.8.1.el9_3	cpe:/a:redhat:enterprise_linux:9	RHSA-2023:6583	2023-11-07T00:00:00Z
kernel-0:5.14.0-362.8.1.el9_3	cpe:/o:redhat:enterprise_linux:9	RHSA-2023:6583	2023-11-07T00:00:00Z

No data available yet.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

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Advisories

Source	ID	Title
EUVD	EUVD-2022-54969	In the Linux kernel, the following vulnerability has been resolved: watch_queue: Fix NULL dereference in error cleanup In watch_queue_set_size(), the error cleanup code doesn't take account of the fact that __free_page() can't handle a NULL pointer when trying to free up buffer pages that did get allocated. Fix this by only calling __free_page() on the pages actually allocated. Without the fix, this can lead to something like the following: BUG: KASAN: null-ptr-deref in __free_pages+0x1f/0x1b0 mm/page_alloc.c:5473 Read of size 4 at addr 0000000000000034 by task syz-executor168/3599 ... Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:446 [inline] kasan_report.cold+0x66/0xdf mm/kasan/report.c:459 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] page_ref_count include/linux/page_ref.h:67 [inline] put_page_testzero include/linux/mm.h:717 [inline] __free_pages+0x1f/0x1b0 mm/page_alloc.c:5473 watch_queue_set_size+0x499/0x630 kernel/watch_queue.c:275 pipe_ioctl+0xac/0x2b0 fs/pipe.c:632 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00024.

Key SSVC decision points have not yet been added.

References

Link	Providers
https://git.kernel.org/stable/c/112a2f9b0a8457794095a0450598f150724ec456
https://git.kernel.org/stable/c/5ae75b4ed30322b42abaa75ef1b784addfdb7dc9
https://git.kernel.org/stable/c/695c47cea02b9101e2fc2e7d36d552128592b347
https://git.kernel.org/stable/c/a635415a064e77bcfbf43da413fd9dfe0bbed9cb
https://git.kernel.org/stable/c/b6f5ad3e45d19f9c4ee3e8a2aff829f28d68591d
https://lore.kernel.org/linux-cve-announce/2025022627-CVE-2022-49257-351f@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2022-49257
https://www.cve.org/CVERecord?id=CVE-2022-49257

History

Mon, 22 Sep 2025 21:00:00 +0000

Type	Values Removed	Values Added
First Time appeared		Linux Linux linux Kernel
Weaknesses		CWE-476
CPEs		cpe:2.3:o:linux:linux_kernel::::::::
Vendors & Products		Linux Linux linux Kernel

Sat, 10 May 2025 03:30:00 +0000

Type	Values Removed	Values Added
First Time appeared		Redhat Redhat enterprise Linux
CPEs		cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:9
Vendors & Products		Redhat Redhat enterprise Linux

Fri, 28 Feb 2025 01:30:00 +0000

Type	Values Removed	Values Added
References		https://lore.kernel.org/linux-cve-announce/2025022627-CVE-2022-49257-351f@gregkh/T https://nvd.nist.gov/vuln/detail/CVE-2022-49257 https://www.cve.org/CVERecord?id=CVE-2022-49257
Metrics	threat_severity `None`	cvssV3_1 `{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}` threat_severity `Low`

Wed, 26 Feb 2025 02:15:00 +0000

Type	Values Removed	Values Added
Description		In the Linux kernel, the following vulnerability has been resolved: watch_queue: Fix NULL dereference in error cleanup In watch_queue_set_size(), the error cleanup code doesn't take account of the fact that __free_page() can't handle a NULL pointer when trying to free up buffer pages that did get allocated. Fix this by only calling __free_page() on the pages actually allocated. Without the fix, this can lead to something like the following: BUG: KASAN: null-ptr-deref in __free_pages+0x1f/0x1b0 mm/page_alloc.c:5473 Read of size 4 at addr 0000000000000034 by task syz-executor168/3599 ... Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106 __kasan_report mm/kasan/report.c:446 [inline] kasan_report.cold+0x66/0xdf mm/kasan/report.c:459 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189 instrument_atomic_read include/linux/instrumented.h:71 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline] page_ref_count include/linux/page_ref.h:67 [inline] put_page_testzero include/linux/mm.h:717 [inline] __free_pages+0x1f/0x1b0 mm/page_alloc.c:5473 watch_queue_set_size+0x499/0x630 kernel/watch_queue.c:275 pipe_ioctl+0xac/0x2b0 fs/pipe.c:632 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:874 [inline] __se_sys_ioctl fs/ioctl.c:860 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae
Title		watch_queue: Fix NULL dereference in error cleanup
References		https://git.kernel.org/stable/c/112a2f9b0a8457794095a0450598f150724ec456 https://git.kernel.org/stable/c/5ae75b4ed30322b42abaa75ef1b784addfdb7dc9 https://git.kernel.org/stable/c/695c47cea02b9101e2fc2e7d36d552128592b347 https://git.kernel.org/stable/c/a635415a064e77bcfbf43da413fd9dfe0bbed9cb https://git.kernel.org/stable/c/b6f5ad3e45d19f9c4ee3e8a2aff829f28d68591d

Subscriptions

Linux Linux Kernel

Redhat Enterprise Linux

MITRE

Status: PUBLISHED

Assigner: Linux

Published: 2025-02-26T01:56:11.072Z

Updated: 2026-05-11T18:56:12.623Z

Reserved: 2025-02-26T01:49:39.296Z

Link: CVE-2022-49257

Vulnrichment

No data.

NVD

Status : Analyzed

Published: 2025-02-26T07:01:02.597

Modified: 2025-09-22T20:56:14.770

Link: CVE-2022-49257

Redhat

Severity : Low

Publid Date: 2025-02-26T00:00:00Z

Links: CVE-2022-49257 - Bugzilla

OpenCVE Enrichment

No data.

Weaknesses

CWE-476

Tracking

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

Subscriptions

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