GHSA-W7V4-JWP5-GR92
Vulnerability from github – Published: 2026-07-25 12:31 – Updated: 2026-07-25 12:31In the Linux kernel, the following vulnerability has been resolved:
io_uring/nop: fix file reference leak with IOSQE_FIXED_FILE
NOP file-acquisition support choses between a fixed (registered) file and a normal fget()'d file based on its own IORING_NOP_FIXED_FILE flag in sqe->nop_flags. However, a request's REQ_F_FIXED_FILE is set independently from the generic IOSQE_FIXED_FILE sqe flag during request init, before the issue handler runs.
If a NOP is submitted with IOSQE_FIXED_FILE set (so REQ_F_FIXED_FILE is set) but without IORING_NOP_FIXED_FILE, io_nop() takes the normal path and grabs a real reference via io_file_get_normal(). On completion, io_put_file() only drops the reference when REQ_F_FIXED_FILE is clear, so the fget()'d file is never released and leaks:
BUG: memory leak unreferenced object 0xffff88800f42c240 (size 176): kmem_cache_alloc_noprof+0x358/0x440 alloc_empty_file+0x57/0x180 path_openat+0x44/0x1e50 do_file_open+0x121/0x200 do_sys_openat2+0xa7/0x150 __x64_sys_openat+0x82/0xf0
Decide between fixed and normal file acquisition from REQ_F_FIXED_FILE, the same way io_assign_file() does for every other opcode, and fold IORING_NOP_FIXED_FILE into REQ_F_FIXED_FILE at prep time.
{
"affected": [],
"aliases": [
"CVE-2026-64426"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-25T10:17:26Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/nop: fix file reference leak with IOSQE_FIXED_FILE\n\nNOP file-acquisition support choses between a fixed (registered) file and\na normal fget()\u0027d file based on its own IORING_NOP_FIXED_FILE flag in\nsqe-\u003enop_flags. However, a request\u0027s REQ_F_FIXED_FILE is set\nindependently from the generic IOSQE_FIXED_FILE sqe flag during request\ninit, before the issue handler runs.\n\nIf a NOP is submitted with IOSQE_FIXED_FILE set (so REQ_F_FIXED_FILE is\nset) but without IORING_NOP_FIXED_FILE, io_nop() takes the normal path\nand grabs a real reference via io_file_get_normal(). On completion,\nio_put_file() only drops the reference when REQ_F_FIXED_FILE is clear,\nso the fget()\u0027d file is never released and leaks:\n\n BUG: memory leak\n unreferenced object 0xffff88800f42c240 (size 176):\n kmem_cache_alloc_noprof+0x358/0x440\n alloc_empty_file+0x57/0x180\n path_openat+0x44/0x1e50\n do_file_open+0x121/0x200\n do_sys_openat2+0xa7/0x150\n __x64_sys_openat+0x82/0xf0\n\nDecide between fixed and normal file acquisition from REQ_F_FIXED_FILE,\nthe same way io_assign_file() does for every other opcode, and fold\nIORING_NOP_FIXED_FILE into REQ_F_FIXED_FILE at prep time.",
"id": "GHSA-w7v4-jwp5-gr92",
"modified": "2026-07-25T12:31:35Z",
"published": "2026-07-25T12:31:35Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64426"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2564ca2e31bd8ee8348362941af2ee4671e487ca"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/722869fcff598fad20d5ab79c305897a7534708b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/7267717f35787167fcce4bc14f6ef3fa06682dcf"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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