GHSA-89JM-XXXG-24XJ

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-20 15:31
VLAI
Details

In the Linux kernel, the following vulnerability has been resolved:

netfs: Fix early put of sink folio in netfs_read_gaps()

Fix netfs_read_gaps() to release the sink page it uses after waiting for the request to complete. The way the sink page is used is that an ITER_BVEC-class iterator is created that has the gaps from the target folio at either end, but has the sink page tiled over the middle so that a single read op can fill in both gaps.

The bug was found by KASAN detecting a UAF on the generic/075 xfstest in the cifsd kernel thread that handles reception of data from the TCP socket:

BUG: KASAN: use-after-free in _copy_to_iter+0x48a/0xa20 Write of size 885 at addr ffff888107f92000 by task cifsd/1285 CPU: 2 UID: 0 PID: 1285 Comm: cifsd Not tainted 7.0.0 #6 PREEMPT(lazy) Call Trace: dump_stack_lvl+0x5d/0x80 print_report+0x17f/0x4f1 kasan_report+0x100/0x1e0 kasan_check_range+0x10f/0x1e0 __asan_memcpy+0x3c/0x60 _copy_to_iter+0x48a/0xa20 __skb_datagram_iter+0x2c9/0x430 skb_copy_datagram_iter+0x6e/0x160 tcp_recvmsg_locked+0xce0/0x1130 tcp_recvmsg+0xeb/0x300 inet_recvmsg+0xcf/0x3a0 sock_recvmsg+0xea/0x100 cifs_readv_from_socket+0x3a6/0x4d0 [cifs] cifs_read_iter_from_socket+0xdd/0x130 [cifs] cifs_readv_receive+0xaad/0xb10 [cifs] cifs_demultiplex_thread+0x1148/0x1740 [cifs] kthread+0x1cf/0x210

Show details on source website

{
  "affected": [],
  "aliases": [
    "CVE-2026-64061"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:46Z",
    "severity": "CRITICAL"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix early put of sink folio in netfs_read_gaps()\n\nFix netfs_read_gaps() to release the sink page it uses after waiting for\nthe request to complete.  The way the sink page is used is that an\nITER_BVEC-class iterator is created that has the gaps from the target folio\nat either end, but has the sink page tiled over the middle so that a single\nread op can fill in both gaps.\n\nThe bug was found by KASAN detecting a UAF on the generic/075 xfstest in\nthe cifsd kernel thread that handles reception of data from the TCP socket:\n\n BUG: KASAN: use-after-free in _copy_to_iter+0x48a/0xa20\n Write of size 885 at addr ffff888107f92000 by task cifsd/1285\n CPU: 2 UID: 0 PID: 1285 Comm: cifsd Not tainted 7.0.0 #6 PREEMPT(lazy)\n Call Trace:\n  dump_stack_lvl+0x5d/0x80\n  print_report+0x17f/0x4f1\n  kasan_report+0x100/0x1e0\n  kasan_check_range+0x10f/0x1e0\n  __asan_memcpy+0x3c/0x60\n  _copy_to_iter+0x48a/0xa20\n  __skb_datagram_iter+0x2c9/0x430\n  skb_copy_datagram_iter+0x6e/0x160\n  tcp_recvmsg_locked+0xce0/0x1130\n  tcp_recvmsg+0xeb/0x300\n  inet_recvmsg+0xcf/0x3a0\n  sock_recvmsg+0xea/0x100\n  cifs_readv_from_socket+0x3a6/0x4d0 [cifs]\n  cifs_read_iter_from_socket+0xdd/0x130 [cifs]\n  cifs_readv_receive+0xaad/0xb10 [cifs]\n  cifs_demultiplex_thread+0x1148/0x1740 [cifs]\n  kthread+0x1cf/0x210",
  "id": "GHSA-89jm-xxxg-24xj",
  "modified": "2026-07-20T15:31:57Z",
  "published": "2026-07-19T18:31:51Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64061"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2a39d49c8d97df8cb8fa80c10859bc1ba7358c6b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/3e5dd91b87a8b1450217b56a336bee315f40da7d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/412e8bad48967fd34295866636c028befd27d8b9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/d4f4bc87c76511cf2532448b0fa40c25e894bd7d"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}



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