{"id":"CVE-2025-68813","title":"ipvs: fix ipv4 null-ptr-deref in route error path","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nipvs: fix ipv4 null-ptr-deref in route error path\n\nThe IPv4 code path in __ip_vs_get_out_rt() calls dst_link_failure()\nwithout ensuring skb->dev is set, leading to a NU…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < dd72a93c80408f06327dd2d956eb1a656d0b5903","Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < 312d7cd88882fc6cadcc08b02287497aaaf94bcd","Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < cdeff10851c37a002d87a035818ebd60fdb74447","Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < 4729ff0581fbb7ad098b6153b76b6f5aac94618a","Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < 25ab24df31f7af843c96a38e0781b9165216e1a8","Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < 689a627d14788ad772e0fa24c2e57a23dbc7ce90","Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < ad891bb3d079a46a821bf2b8867854645191bab0","Linux 6c2fa855d8178699706b1192db2f1f8102b0ba1e","Linux fbf569d2beee2a4a7a0bc8b619c26101d1211a88","Linux ff71f99d5fb2daf54340e8b290d0bc4e6b4c1d38","Linux 3d988fcddbe7b8673a231958bd2fba61b5a7ced9","Linux 8a430e56a6485267a1b2d3747209d26c54d1a34b","Linux 6bd1ee0a993fc9574ae43c1994c54a60cb23a380","Linux >= 3.18.139 < 3.19","Linux >= 4.4.179 < 4.5","Linux >= 4.9.171 < 4.10","Linux >= 4.14.114 < 4.15","Linux >= 4.19.37 < 4.20","Linux >= 5.0.10 < 5.1","Linux 5.1"],"ssvc":{"exploitation":"none","automatable":"yes","technicalImpact":"partial","timestamp":"2026-06-16T19:15:40.029608Z"},"published":"2026-01-13","updated":"2026-10-19","sourceUpdated":"2026-10-19T18:05:08.415Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-68813","references":[{"url":"https://git.kernel.org/stable/c/dd72a93c80408f06327dd2d956eb1a656d0b5903"},{"url":"https://git.kernel.org/stable/c/312d7cd88882fc6cadcc08b02287497aaaf94bcd"},{"url":"https://git.kernel.org/stable/c/cdeff10851c37a002d87a035818ebd60fdb74447"},{"url":"https://git.kernel.org/stable/c/4729ff0581fbb7ad098b6153b76b6f5aac94618a"},{"url":"https://git.kernel.org/stable/c/25ab24df31f7af843c96a38e0781b9165216e1a8"},{"url":"https://git.kernel.org/stable/c/689a627d14788ad772e0fa24c2e57a23dbc7ce90"},{"url":"https://git.kernel.org/stable/c/ad891bb3d079a46a821bf2b8867854645191bab0"}],"tags":["cve.org"],"epss":0.00207,"epssPercentile":0.10158,"ingestedAt":"2026-10-19T18:35:50.150Z","slug":"CVE-2025-68813","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nipvs: fix ipv4 null-ptr-deref in route error path\n\nThe IPv4 code path in __ip_vs_get_out_rt() calls dst_link_failure()\nwithout ensuring skb->dev is set, leading to a NULL pointer dereference\nin fib_compute_spec_dst() when ipv4_link_failure() attempts to send\nICMP destination unreachable messages.\n\nThe issue emerged after commit ed0de45a1008 (\"ipv4: recompile ip options\nin ipv4_link_failure\") started calling __ip_options_compile() from\nipv4_link_failure(). This code path eventually calls fib_compute_spec_dst()\nwhich dereferences skb->dev. An attempt was made to fix the NULL skb->dev\ndereference in commit 0113d9c9d1cc (\"ipv4: fix null-deref in\nipv4_link_failure\"), but it only addressed the immediate dev_net(skb->dev)\ndereference by using a fallback device. The fix was incomplete because\nfib_compute_spec_dst() later in the call chain still accesses skb->dev\ndirectly, which remains NULL when IPVS calls dst_link_failure().\n\nThe crash occurs when:\n1. IPVS processes a packet in NAT mode with a misconfigured destination\n2. Route lookup fails in __ip_vs_get_out_rt() before establishing a route\n3. The error path calls dst_link_failure(skb) with skb->dev == NULL\n4. ipv4_link_failure() → ipv4_send_dest_unreach() →\n   __ip_options_compile() → fib_compute_spec_dst()\n5. fib_compute_spec_dst() dereferences NULL skb->dev\n\nApply the same fix used for IPv6 in commit 326bf17ea5d4 (\"ipvs: fix\nipv6 route unreach panic\"): set skb->dev from skb_dst(skb)->dev before\ncalling dst_link_failure().\n\nKASAN: null-ptr-deref in range [0x0000000000000328-0x000000000000032f]\nCPU: 1 PID: 12732 Comm: syz.1.3469 Not tainted 6.6.114 #2\nRIP: 0010:__in_dev_get_rcu include/linux/inetdevice.h:233\nRIP: 0010:fib_compute_spec_dst+0x17a/0x9f0 net/ipv4/fib_frontend.c:285\nCall Trace:\n  <TASK>\n  spec_dst_fill net/ipv4/ip_options.c:232\n  spec_dst_fill net/ipv4/ip_options.c:229\n  __ip_options_compile+0x13a1/0x17d0 net/ipv4/ip_options.c:330\n  ipv4_send_dest_unreach net/ipv4/route.c:1252\n  ipv4_link_failure+0x702/0xb80 net/ipv4/route.c:1265\n  dst_link_failure include/net/dst.h:437\n  __ip_vs_get_out_rt+0x15fd/0x19e0 net/netfilter/ipvs/ip_vs_xmit.c:412\n  ip_vs_nat_xmit+0x1d8/0xc80 net/netfilter/ipvs/ip_vs_xmit.c:764\n\n## Affected\n\n- `Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < dd72a93c80408f06327dd2d956eb1a656d0b5903`\n- `Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < 312d7cd88882fc6cadcc08b02287497aaaf94bcd`\n- `Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < cdeff10851c37a002d87a035818ebd60fdb74447`\n- `Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < 4729ff0581fbb7ad098b6153b76b6f5aac94618a`\n- `Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < 25ab24df31f7af843c96a38e0781b9165216e1a8`\n- `Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < 689a627d14788ad772e0fa24c2e57a23dbc7ce90`\n- `Linux >= ed0de45a1008991fdaa27a0152befcb74d126a8b < ad891bb3d079a46a821bf2b8867854645191bab0`\n- `Linux 6c2fa855d8178699706b1192db2f1f8102b0ba1e`\n- `Linux fbf569d2beee2a4a7a0bc8b619c26101d1211a88`\n- `Linux ff71f99d5fb2daf54340e8b290d0bc4e6b4c1d38`\n- `Linux 3d988fcddbe7b8673a231958bd2fba61b5a7ced9`\n- `Linux 8a430e56a6485267a1b2d3747209d26c54d1a34b`\n- `Linux 6bd1ee0a993fc9574ae43c1994c54a60cb23a380`\n- `Linux >= 3.18.139 < 3.19`\n- `Linux >= 4.4.179 < 4.5`\n- `Linux >= 4.9.171 < 4.10`\n- `Linux >= 4.14.114 < 4.15`\n- `Linux >= 4.19.37 < 4.20`\n- `Linux >= 5.0.10 < 5.1`\n- `Linux 5.1`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}