GHSA-GQRM-563W-26QF
Vulnerability from github – Published: 2026-08-15 06:32 – Updated: 2026-08-19 18:32In the Linux kernel, the following vulnerability has been resolved:
ipv6: fib6: fix NULL deref in fib6_walk_continue() on multi-batch dump
inet6_dump_fib() saves its progress in cb->args[1] as a positional index within the current hash chain. Between batches, a concurrent fib6_new_table() can insert a new table at the chain head, shifting all existing entries. The saved index then lands on a different table, causing fib6_dump_table() to set w->root to the wrong table while w->node still points into the previous one. fib6_walk_continue() dereferences w->node->parent (NULL) and panics:
BUG: kernel NULL pointer dereference, address: 0000000000000008 RIP: 0010:fib6_walk_continue+0x6e/0x170 Call Trace: fib6_dump_table.isra.0+0xc5/0x240 inet6_dump_fib+0xf6/0x420 rtnl_dumpit+0x30/0xa0 netlink_dump+0x15b/0x460 netlink_recvmsg+0x1d6/0x2a0 ____sys_recvmsg+0x17a/0x190
Fix by storing tb->tb6_id in cb->args[1] instead of a positional index. On resume, skip entries until the id matches; a concurrent head-insert can never match the saved id, so the walker always resumes on the correct table.
{
"affected": [],
"aliases": [
"CVE-2026-72392"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-15T06:22:12Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: fib6: fix NULL deref in fib6_walk_continue() on multi-batch dump\n\ninet6_dump_fib() saves its progress in cb-\u003eargs[1] as a positional\nindex within the current hash chain. Between batches, a concurrent\nfib6_new_table() can insert a new table at the chain head, shifting\nall existing entries. The saved index then lands on a different\ntable, causing fib6_dump_table() to set w-\u003eroot to the wrong table\nwhile w-\u003enode still points into the previous one.\nfib6_walk_continue() dereferences w-\u003enode-\u003eparent (NULL) and panics:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000008\n RIP: 0010:fib6_walk_continue+0x6e/0x170\n Call Trace:\n \u003cTASK\u003e\n fib6_dump_table.isra.0+0xc5/0x240\n inet6_dump_fib+0xf6/0x420\n rtnl_dumpit+0x30/0xa0\n netlink_dump+0x15b/0x460\n netlink_recvmsg+0x1d6/0x2a0\n ____sys_recvmsg+0x17a/0x190\n\nFix by storing tb-\u003etb6_id in cb-\u003eargs[1] instead of a positional\nindex. On resume, skip entries until the id matches; a concurrent\nhead-insert can never match the saved id, so the walker always\nresumes on the correct table.",
"id": "GHSA-gqrm-563w-26qf",
"modified": "2026-08-19T18:32:27Z",
"published": "2026-08-15T06:32:22Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-72392"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/059efb48dd746518898faaa9b965511009b59639"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/110ccbd28c9444866fcc84ba96a2ad64fa6e95ae"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/27210d433a8c5fe6bf7278a04bbaeb49a81d0290"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/89f9c5fee3c64c5cabc34e65599308fd3c879cf9"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9facb861dc6b9b9ea9793ef5032a9a826f7a4229"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/cb90a774a9c6c46961a44949a246fbb61f5f934c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d8a01d27873e04bebd357dc87859aa756e0b28b2"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ee73a32dd258d4af66831ff006b771e19812b322"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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