{"cve":"CVE-2025-38638","nvd":{"published":"2025-08-22T16:15:37.713","modified":"2026-06-17T09:17:16.070","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: add a retry logic in net6_rt_notify()\n\ninet6_rt_notify() can be called under RCU protection only.\nThis means the route could be changed concurrently\nand rt6_fill_node() could return -EMSGSIZE.\n\nRe-size the skb when this happens and retry, removing\none WARN_ON() that syzbot was able to trigger:\n\nWARNING: CPU: 3 PID: 6291 at net/ipv6/route.c:6342 inet6_rt_notify+0x475/0x4b0 net/ipv6/route.c:6342\nModules linked in:\nCPU: 3 UID: 0 PID: 6291 Comm: syz.0.77 Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(full)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014\n RIP: 0010:inet6_rt_notify+0x475/0x4b0 net/ipv6/route.c:6342\nCode: fc ff ff e8 6d 52 ea f7 e9 47 fc ff ff 48 8b 7c 24 08 4c 89 04 24 e8 5a 52 ea f7 4c 8b 04 24 e9 94 fd ff ff e8 9c fe 84 f7 90 <0f> 0b 90 e9 bd fd ff ff e8 6e 52 ea f7 e9 bb fb ff ff 48 89 df e8\nRSP: 0018:ffffc900035cf1d8 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: ffffc900035cf540 RCX: ffffffff8a36e790\nRDX: ffff88802f7e8000 RSI: ffffffff8a36e9d4 RDI: 0000000000000005\nRBP: ffff88803c230f00 R08: 0000000000000005 R09: 00000000ffffffa6\nR10: 00000000ffffffa6 R11: 0000000000000001 R12: 00000000ffffffa6\nR13: 0000000000000900 R14: ffff888032ea4100 R15: 0000000000000000\nFS:  00007fac7b89a6c0(0000) GS:ffff8880d6a20000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007fac7b899f98 CR3: 0000000034b3f000 CR4: 0000000000352ef0\nCall Trace:\n <TASK>\n  ip6_route_mpath_notify+0xde/0x280 net/ipv6/route.c:5356\n  ip6_route_multipath_add+0x1181/0x1bd0 net/ipv6/route.c:5536\n  inet6_rtm_newroute+0xe4/0x1a0 net/ipv6/route.c:5647\n  rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944\n  netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552\n  netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]\n  netlink_unicast+0x58d/0x850 net/netlink/af_netlink.c:1346\n  netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896\n  sock_sendmsg_nosec net/socket.c:712 [inline]\n  __sock_sendmsg net/socket.c:727 [inline]\n  ____sys_sendmsg+0xa95/0xc70 net/socket.c:2566\n  ___sys_sendmsg+0x134/0x1d0 net/socket.c:2620","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":[],"references":["https://git.kernel.org/stable/c/0bdca3439a22c70eb8f404acd61bf7aca5d731b0","https://git.kernel.org/stable/c/ea2f921db7a483a526058c5b5b8162edd88dabe5"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:07:46.309729541+00:00"},"epss":{"cve":"CVE-2025-38638","score":0.0014,"percentile":0.03337,"date":"2026-11-01"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}