CVE-2022-49256 [Medium] | Information Disclosure in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: watch_queue: Actually free the watch free_watch() does everything barring actually freeing the watch object. Fix this by adding the missing kfree. kmemleak produces a report something like the following. Note that as an address can be seen in the first word, the watch would appear to have gone through call_rcu(). BUG: memory leak unreferenced object 0xffff88810ce4a200 (size 96): comm "syz-executor352", pid 3605, jiffies 4294947473 (age 13.720s) hex dump (first 32 bytes): e0 82 48 0d 81 88 ff ff 00 00 00 00 00 00 00 00 ..H............. 80 a2 e4 0c 81 88 ff ff 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff8214e6cc>] kmalloc include/linux/slab.h:581 [inline] [<ffffffff8214e6cc>] kzalloc include/linux/slab.h:714 [inline] [<ffffffff8214e6cc>] keyctl_watch_key+0xec/0x2e0 security/keys/keyctl.c:1800 [<ffffffff8214ec84>] __do_sys_keyctl+0x3c4/0x490 security/keys/keyctl.c:2016 [<ffffffff84493a25>] do_syscall_x64 arch/x86/entry/common.c:50 [inline] [<ffffffff84493a25>] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 [<ffffffff84600068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-04-06	0.03%	0.11%	+0.08%
2	2025-11-21	0.06%	0.03%	-0.03%
3	2025-11-18	—	0.06%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-04-06

0.03%

0.11%

+0.08%

2025-11-21

0.06%

0.03%

-0.03%

2025-11-18

—

0.06%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
5.5	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

5.5

3.1

MEDIUM

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

3.6

[email protected]

OS Trackers for CVE-2022-49256

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2022-49256 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2022-49256
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2022-49256
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2022-49256/
`ubuntu`	medium	CVE-2022-49256 medium priority: Ubuntu including 130 source packages (linux, linux-allwinner-5.19, …), 1040 status rows across 8 suites (bionic, focal, jammy, noble, oracular, trusty, upstream, xenial): DNE 713, ignored 146, not-affected 101, released 80.	https://ubuntu.com/security/CVE-2022-49256

Affected software / configurations for CVE-2022-49256

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 5.8, < 5.10.110	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.33	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 5.16.19	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.17, < 5.17.2	cpe:2.3:o:linux:linux_kernel::::::::

References for CVE-2022-49256

URL	Tags
https://git.kernel.org/stable/c/31824613a42aacdcbeb325bf07a1c8247a11ebe2	Patch
https://git.kernel.org/stable/c/3d8dcf278b1ee1eff1e90be848fa2237db4c07a7	Patch
https://git.kernel.org/stable/c/7e8c9b0df07a77f0d072603b8ced2677e30e1893	Patch
https://git.kernel.org/stable/c/9d92be1a09fbb3dd65600dbfe7eedb40e7228e4b	Patch
https://git.kernel.org/stable/c/f69aecb49968e14196366bbe896eab0a904229f5	Patch

URL

CVE-2022-49256 | watch_queue: Actually free the watch

Exploit prediction scoring system (EPSS) score for CVE-2022-49256

Common vulnerability scoring system (CVSS) metrics for CVE-2022-49256

Weakness enumeration for CVE-2022-49256

OS Trackers for CVE-2022-49256

Affected software / configurations for CVE-2022-49256

References for CVE-2022-49256