ghsa-4w7v-gw2g-gqwc
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
ipv6: add a retry logic in net6_rt_notify()
inet6_rt_notify() can be called under RCU protection only. This means the route could be changed concurrently and rt6_fill_node() could return -EMSGSIZE.
Re-size the skb when this happens and retry, removing one WARN_ON() that syzbot was able to trigger:
WARNING: CPU: 3 PID: 6291 at net/ipv6/route.c:6342 inet6_rt_notify+0x475/0x4b0 net/ipv6/route.c:6342 Modules linked in: CPU: 3 UID: 0 PID: 6291 Comm: syz.0.77 Not tainted 6.16.0-rc7-syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:inet6_rt_notify+0x475/0x4b0 net/ipv6/route.c:6342 Code: 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 RSP: 0018:ffffc900035cf1d8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffffc900035cf540 RCX: ffffffff8a36e790 RDX: ffff88802f7e8000 RSI: ffffffff8a36e9d4 RDI: 0000000000000005 RBP: ffff88803c230f00 R08: 0000000000000005 R09: 00000000ffffffa6 R10: 00000000ffffffa6 R11: 0000000000000001 R12: 00000000ffffffa6 R13: 0000000000000900 R14: ffff888032ea4100 R15: 0000000000000000 FS: 00007fac7b89a6c0(0000) GS:ffff8880d6a20000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fac7b899f98 CR3: 0000000034b3f000 CR4: 0000000000352ef0 Call Trace: ip6_route_mpath_notify+0xde/0x280 net/ipv6/route.c:5356 ip6_route_multipath_add+0x1181/0x1bd0 net/ipv6/route.c:5536 inet6_rtm_newroute+0xe4/0x1a0 net/ipv6/route.c:5647 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x155/0x420 net/netlink/af_netlink.c:2552 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x58d/0x850 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8d1/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] _syssendmsg+0xa95/0xc70 net/socket.c:2566 _sys_sendmsg+0x134/0x1d0 net/socket.c:2620
{
"affected": [],
"aliases": [
"CVE-2025-38638"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-08-22T16:15:37Z",
"severity": null
},
"details": "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 \u003c0f\u003e 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 \u003cTASK\u003e\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",
"id": "GHSA-4w7v-gw2g-gqwc",
"modified": "2025-08-22T18:31:22Z",
"published": "2025-08-22T18:31:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2025-38638"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0bdca3439a22c70eb8f404acd61bf7aca5d731b0"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ea2f921db7a483a526058c5b5b8162edd88dabe5"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
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