CVE-2022-49649 [Medium] | Security Vulnerability in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: xen/netback: avoid entering xenvif_rx_next_skb() with an empty rx queue xenvif_rx_next_skb() is expecting the rx queue not being empty, but in case the loop in xenvif_rx_action() is doing multiple iterations, the availability of another skb in the rx queue is not being checked. This can lead to crashes: [40072.537261] BUG: unable to handle kernel NULL pointer dereference at 0000000000000080 [40072.537407] IP: xenvif_rx_skb+0x23/0x590 [xen_netback] [40072.537534] PGD 0 P4D 0 [40072.537644] Oops: 0000 [#1] SMP NOPTI [40072.537749] CPU: 0 PID: 12505 Comm: v1-c40247-q2-gu Not tainted 4.12.14-122.121-default #1 SLE12-SP5 [40072.537867] Hardware name: HP ProLiant DL580 Gen9/ProLiant DL580 Gen9, BIOS U17 11/23/2021 [40072.537999] task: ffff880433b38100 task.stack: ffffc90043d40000 [40072.538112] RIP: e030:xenvif_rx_skb+0x23/0x590 [xen_netback] [40072.538217] RSP: e02b:ffffc90043d43de0 EFLAGS: 00010246 [40072.538319] RAX: 0000000000000000 RBX: ffffc90043cd7cd0 RCX: 00000000000000f7 [40072.538430] RDX: 0000000000000000 RSI: 0000000000000006 RDI: ffffc90043d43df8 [40072.538531] RBP: 000000000000003f R08: 000077ff80000000 R09: 0000000000000008 [40072.538644] R10: 0000000000007ff0 R11: 00000000000008f6 R12: ffffc90043ce2708 [40072.538745] R13: 0000000000000000 R14: ffffc90043d43ed0 R15: ffff88043ea748c0 [40072.538861] FS: 0000000000000000(0000) GS:ffff880484600000(0000) knlGS:0000000000000000 [40072.538988] CS: e033 DS: 0000 ES: 0000 CR0: 0000000080050033 [40072.539088] CR2: 0000000000000080 CR3: 0000000407ac8000 CR4: 0000000000040660 [40072.539211] Call Trace: [40072.539319] xenvif_rx_action+0x71/0x90 [xen_netback] [40072.539429] xenvif_kthread_guest_rx+0x14a/0x29c [xen_netback] Fix that by stopping the loop in case the rx queue becomes empty.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.03%	0.24%	+0.21%
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)

2026-06-15

0.03%

0.24%

+0.21%

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]
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	134c704f-9b21-4f2e-91b3-4a467353bcc0

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]

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

134c704f-9b21-4f2e-91b3-4a467353bcc0

OS Trackers for CVE-2022-49649

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2022-49649 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-2022-49649
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2022-49649
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2022-49649/
`ubuntu`	medium	CVE-2022-49649 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, released 151, ignored 146, not-affected 108, needs-triage 1.	https://ubuntu.com/security/CVE-2022-49649

Affected software / configurations for CVE-2022-49649

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 4.9, < 4.9.324	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.10, < 4.14.289	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.15, < 4.19.253	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 4.20, < 5.4.207	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.5, < 5.10.132	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.56	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 5.18.13	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc1::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc2::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc3::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc4::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc5::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc6::::::

References for CVE-2022-49649

URL	Tags
https://git.kernel.org/stable/c/5a071aefd6414af5a20321ab58a0557b81993687	Patch
https://git.kernel.org/stable/c/7425479d20f9e96f7c3ec8e8a93fe0d7478724cb	Patch
https://git.kernel.org/stable/c/94e8100678889ab428e68acadf042de723f094b9	Patch
https://git.kernel.org/stable/c/b99174ac57fe5d8867448c03b23828e63f24cb1c	Patch
https://git.kernel.org/stable/c/b9c32a6886af79d6e0ad87a7b01800ed079cdd02	Patch
https://git.kernel.org/stable/c/c0fcceb5f3f1ec197c014fe218c2f28108cacd27	Patch
https://git.kernel.org/stable/c/d5320c6a27aa975aff740f9cb481dcbde48f4348	Patch
https://git.kernel.org/stable/c/f0b5c819b062df8bf5f2acf4697e3871cb3722da	Patch

URL

CVE-2022-49649 | xen/netback: avoid entering xenvif_rx_next_skb() with an empty rx queue

Exploit prediction scoring system (EPSS) score for CVE-2022-49649

Common vulnerability scoring system (CVSS) metrics for CVE-2022-49649

Weakness enumeration for CVE-2022-49649

OS Trackers for CVE-2022-49649

Affected software / configurations for CVE-2022-49649

References for CVE-2022-49649