Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2/6.19-rc1 inetdevice.h __ip_vs_get_out_rt null pointer dereference

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CTI Interest Score
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4.6$0-$5k0.00

Summaryinfo

A vulnerability has been found in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2/6.19-rc1 and classified as critical. Affected by this vulnerability is the function __ip_vs_get_out_rt in the library include/linux/inetdevice.h. The manipulation leads to null pointer dereference. This vulnerability is uniquely identified as CVE-2025-68813. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.1.159/6.6.119/6.12.63/6.18.2/6.19-rc1 and classified as critical. This issue affects the function __ip_vs_get_out_rt in the library include/linux/inetdevice.h. The manipulation with an unknown input leads to a null pointer dereference vulnerability. Using CWE to declare the problem leads to CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ipvs: fix ipv4 null-ptr-deref in route error path The IPv4 code path in __ip_vs_get_out_rt() calls dst_link_failure() without ensuring skb->dev is set, leading to a NULL pointer dereference in fib_compute_spec_dst() when ipv4_link_failure() attempts to send ICMP destination unreachable messages. The issue emerged after commit ed0de45a1008 ("ipv4: recompile ip options in ipv4_link_failure") started calling __ip_options_compile() from ipv4_link_failure(). This code path eventually calls fib_compute_spec_dst() which dereferences skb->dev. An attempt was made to fix the NULL skb->dev dereference in commit 0113d9c9d1cc ("ipv4: fix null-deref in ipv4_link_failure"), but it only addressed the immediate dev_net(skb->dev) dereference by using a fallback device. The fix was incomplete because fib_compute_spec_dst() later in the call chain still accesses skb->dev directly, which remains NULL when IPVS calls dst_link_failure(). The crash occurs when: 1. IPVS processes a packet in NAT mode with a misconfigured destination 2. Route lookup fails in __ip_vs_get_out_rt() before establishing a route 3. The error path calls dst_link_failure(skb) with skb->dev == NULL 4. ipv4_link_failure() → ipv4_send_dest_unreach() → __ip_options_compile() → fib_compute_spec_dst() 5. fib_compute_spec_dst() dereferences NULL skb->dev Apply the same fix used for IPv6 in commit 326bf17ea5d4 ("ipvs: fix ipv6 route unreach panic"): set skb->dev from skb_dst(skb)->dev before calling dst_link_failure(). KASAN: null-ptr-deref in range [0x0000000000000328-0x000000000000032f] CPU: 1 PID: 12732 Comm: syz.1.3469 Not tainted 6.6.114 #2 RIP: 0010:__in_dev_get_rcu include/linux/inetdevice.h:233 RIP: 0010:fib_compute_spec_dst+0x17a/0x9f0 net/ipv4/fib_frontend.c:285 Call Trace: <TASK> spec_dst_fill net/ipv4/ip_options.c:232 spec_dst_fill net/ipv4/ip_options.c:229 __ip_options_compile+0x13a1/0x17d0 net/ipv4/ip_options.c:330 ipv4_send_dest_unreach net/ipv4/route.c:1252 ipv4_link_failure+0x702/0xb80 net/ipv4/route.c:1265 dst_link_failure include/net/dst.h:437 __ip_vs_get_out_rt+0x15fd/0x19e0 net/netfilter/ipvs/ip_vs_xmit.c:412 ip_vs_nat_xmit+0x1d8/0xc80 net/netfilter/ipvs/ip_vs_xmit.c:764

The advisory is shared at git.kernel.org. The identification of this vulnerability is CVE-2025-68813 since 12/24/2025. The exploitation is known to be difficult. Technical details are known, but no exploit is available.

The vulnerability scanner Nessus provides a plugin with the ID 298659 (Debian dla-4476 : linux-config-6.1 - security update), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.1.160, 6.6.120, 6.12.64, 6.18.3 or 6.19-rc2 eliminates this vulnerability. Applying the patch cdeff10851c37a002d87a035818ebd60fdb74447/4729ff0581fbb7ad098b6153b76b6f5aac94618a/25ab24df31f7af843c96a38e0781b9165216e1a8/689a627d14788ad772e0fa24c2e57a23dbc7ce90/ad891bb3d079a46a821bf2b8867854645191bab0 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (298659). If you want to get the best quality for vulnerability data then you always have to consider VulDB.

Productinfo

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CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.8
VulDB Meta Temp Score: 4.6

VulDB Base Score: 4.8
VulDB Temp Score: 4.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 298659
Nessus Name: Debian dla-4476 : linux-config-6.1 - security update

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.1.160/6.6.120/6.12.64/6.18.3/6.19-rc2
Patch: cdeff10851c37a002d87a035818ebd60fdb74447/4729ff0581fbb7ad098b6153b76b6f5aac94618a/25ab24df31f7af843c96a38e0781b9165216e1a8/689a627d14788ad772e0fa24c2e57a23dbc7ce90/ad891bb3d079a46a821bf2b8867854645191bab0

Timelineinfo

12/24/2025 CVE reserved
01/13/2026 +20 days Advisory disclosed
01/13/2026 +0 days VulDB entry created
02/12/2026 +30 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-68813 (🔒)
GCVE (CVE): GCVE-0-2025-68813
GCVE (VulDB): GCVE-100-340637

Entryinfo

Created: 01/13/2026 17:32
Updated: 02/12/2026 08:47
Changes: 01/13/2026 17:32 (59), 01/16/2026 02:21 (1), 02/12/2026 08:47 (2)
Complete: 🔍
Cache ID: 216:766:103

If you want to get the best quality for vulnerability data then you always have to consider VulDB.

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