In 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.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
No data.
No data.
No data.
References
History
Sat, 25 Jul 2026 09:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In 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. | |
| Title | io_uring/nop: fix file reference leak with IOSQE_FIXED_FILE | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-07-25T08:51:03.867Z
Reserved: 2026-07-19T15:36:31.787Z
Link: CVE-2026-64426
Vulnrichment
No data.
NVD
No data.
Redhat
No data.
OpenCVE Enrichment
No data.