{"id":"CVE-2026-31774","revision":"0de142d2eb964d03833d6f339eebe48b","records":[{"revision":"0de142d2eb964d03833d6f339eebe48b","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-31774","aliases":[],"title":"io_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs()","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/net: fix slab-out-of-bounds read in io_bundle_nbufs()\n\nsqe->len is __u32 but gets stored into sr->len which is int. When\nuserspace passes sqe->len values exceeding INT_MAX (e.g. 0xFFFFFFFF),\nsr->len overflows to a negative value. This negative value propagates\nthrough the bundle recv/send path:\n\n  1. io_recv(): sel.val = sr->len (ssize_t gets -1)\n  2. io_recv_buf_select(): arg.max_len = sel->val (size_t gets\n     0xFFFFFFFFFFFFFFFF)\n  3. io_ring_buffers_peek(): buf->len is not clamped because max_len\n     is astronomically large\n  4. iov[].iov_len = 0xFFFFFFFF flows into io_bundle_nbufs()\n  5. io_bundle_nbufs(): min_t(int, 0xFFFFFFFF, ret) yields -1,\n     causing ret to increase instead of decrease, creating an\n     infinite loop that reads past the allocated iov[] array\n\nThis results in a slab-out-of-bounds read in io_bundle_nbufs() from\nthe kmalloc-64 slab, as nbufs increments past the allocated iovec\nentries.\n\n  BUG: KASAN: slab-out-of-bounds in io_bundle_nbufs+0x128/0x160\n  Read of size 8 at addr ffff888100ae05c8 by task exp/145\n  Call Trace:\n   io_bundle_nbufs+0x128/0x160\n   io_recv_finish+0x117/0xe20\n   io_recv+0x2db/0x1160\n\nFix this by rejecting negative sr->len values early in both\nio_sendmsg_prep() and io_recvmsg_prep(). Since sqe->len is __u32,\nany value > INT_MAX indicates overflow and is not a valid length.","state":0,"publishedAt":"2026-05-01T14:15:02.903+00:00","modifiedAt":"2026-10-19T19:06:08.469+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"io_uring/net.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"a05d1f625c7aa681d8816bc0f10089289ad07aad\",\n                            \"lessThan\": \"90ced24c500ad4e129e9e34b7e56fd7849e350b6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a05d1f625c7aa681d8816bc0f10089289ad07aad\",\n                            \"lessThan\": \"c314b405dcc4d8b9041124f928f81715d6328bec\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a05d1f625c7aa681d8816bc0f10089289ad07aad\",\n                            \"lessThan\": \"1b655cd311344117d3052f6552cb20d9901c9d7c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"a05d1f625c7aa681d8816bc0f10089289ad07aad\",\n                            \"lessThan\": \"b948f9d5d3057b01188e36664e7c7604d1c8ecb5\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"io_uring/net.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.10\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"6.10\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.81\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.22\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.19.12\",\n                            \"lessThanOrEqual\": \"6.19.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.0\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[{"system":"CVSS 3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","score":7.1,"severity":"HIGH"}],"references":["https://git.kernel.org/stable/c/90ced24c500ad4e129e9e34b7e56fd7849e350b6","https://git.kernel.org/stable/c/c314b405dcc4d8b9041124f928f81715d6328bec","https://git.kernel.org/stable/c/1b655cd311344117d3052f6552cb20d9901c9d7c","https://git.kernel.org/stable/c/b948f9d5d3057b01188e36664e7c7604d1c8ecb5"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-31774","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-31774","identifiers":["CVE-2026-31774"]},"retained":false,"historicalAffected":[]}],"coverage":[]}