CVE-2025-22056 [High] | Out-of-bounds Write in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: netfilter: nft_tunnel: fix geneve_opt type confusion addition When handling multiple NFTA_TUNNEL_KEY_OPTS_GENEVE attributes, the parsing logic should place every geneve_opt structure one by one compactly. Hence, when deciding the next geneve_opt position, the pointer addition should be in units of char *. However, the current implementation erroneously does type conversion before the addition, which will lead to heap out-of-bounds write. [ 6.989857] ================================================================== [ 6.990293] BUG: KASAN: slab-out-of-bounds in nft_tunnel_obj_init+0x977/0xa70 [ 6.990725] Write of size 124 at addr ffff888005f18974 by task poc/178 [ 6.991162] [ 6.991259] CPU: 0 PID: 178 Comm: poc-oob-write Not tainted 6.1.132 #1 [ 6.991655] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 [ 6.992281] Call Trace: [ 6.992423] <TASK> [ 6.992586] dump_stack_lvl+0x44/0x5c [ 6.992801] print_report+0x184/0x4be [ 6.993790] kasan_report+0xc5/0x100 [ 6.994252] kasan_check_range+0xf3/0x1a0 [ 6.994486] memcpy+0x38/0x60 [ 6.994692] nft_tunnel_obj_init+0x977/0xa70 [ 6.995677] nft_obj_init+0x10c/0x1b0 [ 6.995891] nf_tables_newobj+0x585/0x950 [ 6.996922] nfnetlink_rcv_batch+0xdf9/0x1020 [ 6.998997] nfnetlink_rcv+0x1df/0x220 [ 6.999537] netlink_unicast+0x395/0x530 [ 7.000771] netlink_sendmsg+0x3d0/0x6d0 [ 7.001462] __sock_sendmsg+0x99/0xa0 [ 7.001707] ____sys_sendmsg+0x409/0x450 [ 7.002391] ___sys_sendmsg+0xfd/0x170 [ 7.003145] __sys_sendmsg+0xea/0x170 [ 7.004359] do_syscall_64+0x5e/0x90 [ 7.005817] entry_SYSCALL_64_after_hwframe+0x6e/0xd8 [ 7.006127] RIP: 0033:0x7ec756d4e407 [ 7.006339] Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 faf [ 7.007364] RSP: 002b:00007ffed5d46760 EFLAGS: 00000202 ORIG_RAX: 000000000000002e [ 7.007827] RAX: ffffffffffffffda RBX: 00007ec756cc4740 RCX: 00007ec756d4e407 [ 7.008223] RDX: 0000000000000000 RSI: 00007ffed5d467f0 RDI: 0000000000000003 [ 7.008620] RBP: 00007ffed5d468a0 R08: 0000000000000000 R09: 0000000000000000 [ 7.009039] R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 [ 7.009429] R13: 00007ffed5d478b0 R14: 00007ec756ee5000 R15: 00005cbd4e655cb8 Fix this bug with correct pointer addition and conversion in parse and dump code.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-06-15	0.03%	0.23%	+0.21%
2	2025-04-17	—	0.03%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-06-15

0.03%

0.23%

+0.21%

2025-04-17

—

0.03%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	[email protected]
7.8	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:H) They could widely tamper with or forge data—trust in the data is badly hurt. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.9	134c704f-9b21-4f2e-91b3-4a467353bcc0

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

[email protected]

7.8

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:H): They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.9

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

OS Trackers for CVE-2025-22056

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2025-22056 not yet assigned priority: Debian including 2 source packages (linux, linux-6.1), 6 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 6.	https://security-tracker.debian.org/tracker/CVE-2025-22056
`redhat`	medium	—	https://access.redhat.com/security/cve/CVE-2025-22056
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2025-22056/
`ubuntu`	medium	CVE-2025-22056 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 178, ignored 149, not-affected 75, needed 2, needs-triage 2.	https://ubuntu.com/security/CVE-2025-22056

Affected software / configurations for CVE-2025-22056

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 5.7, < 5.10.236	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.180	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.1.134	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.2, < 6.6.87	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.7, < 6.12.23	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.13, < 6.13.11	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.14, < 6.14.2	cpe:2.3:o:linux:linux_kernel::::::::

References for CVE-2025-22056

URL	Tags
https://git.kernel.org/stable/c/0a93a710d6df334b828ea064c6d39fda34f901dc	Patch
https://git.kernel.org/stable/c/1b755d8eb1ace3870789d48fbd94f386ad6e30be	Patch
https://git.kernel.org/stable/c/28d88ee1e1cc8ac2d79aeb112717b97c5c833d43	Patch
https://git.kernel.org/stable/c/31d49eb436f2da61280508d7adf8c9b473b967aa	Patch
https://git.kernel.org/stable/c/446d94898c560ed2f61e26ae445858a4c4830762	Patch
https://git.kernel.org/stable/c/708e268acb3a446ad2a8a3d2e9bd41cc23660cd6	Patch
https://git.kernel.org/stable/c/a263d31c8c92e5919d41af57d9479cfb66323782	Patch
https://git.kernel.org/stable/c/ca2adfc03cd6273f0b589fe65afc6f75e0fe116e	Patch
https://lists.debian.org/debian-lts-announce/2025/05/msg00030.html
https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html

URL

CVE-2025-22056 | netfilter: nft_tunnel: fix geneve_opt type confusion addition

Exploit prediction scoring system (EPSS) score for CVE-2025-22056

Common vulnerability scoring system (CVSS) metrics for CVE-2025-22056

Weakness enumeration for CVE-2025-22056

OS Trackers for CVE-2025-22056

Affected software / configurations for CVE-2025-22056

References for CVE-2025-22056