In the Linux kernel, the following vulnerability has been resolved:
io_uring/net: inherit IORING_CQE_F_BUF_MORE across bundle recv retries
When a bundle recv retries inside io_recv_finish(), the merge logic OR
the saved cflags from the previous iteration with the cflags returned by
the new iteration:
cflags = req->cqe.flags | (cflags & CQE_F_MASK);
Bits listed in CQE_F_MASK are inherited from the new iteration, and all
other bits (notably IORING_CQE_F_BUFFER and the buffer ID) come from the
saved cflags. Before this change CQE_F_MASK covered only
IORING_CQE_F_SOCK_NONEMPTY and IORING_CQE_F_MORE.
When using provided buffer rings (IOU_PBUF_RING_INC) with incremental
mode, and bundle recv, io_kbuf_inc_commit() can leave the head ring
entry partially consumed, __io_put_kbufs() then sets
IORING_CQE_F_BUF_MORE on the returned cflags so userspace knows the
buffer ID will be reused for subsequent completions.
Because IORING_CQE_F_BUF_MORE was not in CQE_F_MASK, the merge above
silently dropped it whenever the final retry iteration partially
consumed the buffer, and the subsequent req->cqe.flags = cflags &
~CQE_F_MASK save would have left a stale IORING_CQE_F_BUF_MORE in the
carried-over cflags had one been present. Userspace would then
wrongfully advance it ring head past an entry the kernel still uses.
Add IORING_CQE_F_BUF_MORE to CQE_F_MASK so it is both inherited from the
new iteration into the user-visible CQE and stripped from the saved
cflags between iterations.
References
Configurations
Configuration 1 (hide)
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History
06 Jul 2026, 12:37
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Linux linux Kernel
Linux |
|
| CWE | NVD-CWE-noinfo | |
| References | () https://git.kernel.org/stable/c/0bbc9481f970b0b4ddb08cfa464db1cc93b74b56 - Patch | |
| References | () https://git.kernel.org/stable/c/4973232a67e4137ab9399f504f7f2bdd847f96d2 - Patch | |
| References | () https://git.kernel.org/stable/c/ed46f39c47eb5530a9c161481a2080d3a869cfaf - Patch | |
| References | () https://git.kernel.org/stable/c/f40570fda3f3a1f96aeaa4aef665ba274b2810b5 - Patch | |
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc5:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:7.1:rc6:*:*:*:*:*:* |
28 Jun 2026, 08:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 7.8 |
25 Jun 2026, 09:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-06-25 09:16
Updated : 2026-07-06 12:37
NVD link : CVE-2026-53191
Mitre link : CVE-2026-53191
CVE.ORG link : CVE-2026-53191
JSON object : View
Products Affected
linux
- linux_kernel
CWE
