{"id":"CVE-2026-43006","summary":"io_uring/rsrc: reject zero-length fixed buffer import","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring/rsrc: reject zero-length fixed buffer import\n\nvalidate_fixed_range() admits buf_addr at the exact end of the\nregistered region when len is zero, because the check uses strict\ngreater-than (buf_end \u003e imu-\u003eubuf + imu-\u003elen).  io_import_fixed()\nthen computes offset == imu-\u003elen, which causes the bvec skip logic\nto advance past the last bio_vec entry and read bv_offset from\nout-of-bounds slab memory.\n\nReturn early from io_import_fixed() when len is zero.  A zero-length\nimport has no data to transfer and should not walk the bvec array\nat all.\n\n  BUG: KASAN: slab-out-of-bounds in io_import_reg_buf+0x697/0x7f0\n  Read of size 4 at addr ffff888002bcc254 by task poc/103\n  Call Trace:\n   io_import_reg_buf+0x697/0x7f0\n   io_write_fixed+0xd9/0x250\n   __io_issue_sqe+0xad/0x710\n   io_issue_sqe+0x7d/0x1100\n   io_submit_sqes+0x86a/0x23c0\n   __do_sys_io_uring_enter+0xa98/0x1590\n  Allocated by task 103:\n  The buggy address is located 12 bytes to the right of\n   allocated 584-byte region [ffff888002bcc000, ffff888002bcc248)","modified":"2026-05-28T03:54:54.910158700Z","published":"2026-05-01T14:15:14.176Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43006.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/040a1e7e0e2f01851fec1dd2d96906f8636a9f75"},{"type":"WEB","url":"https://git.kernel.org/stable/c/111a12b422a8cfa93deabaef26fec48237163214"},{"type":"WEB","url":"https://git.kernel.org/stable/c/40170fc1a79c1b2e68f09ae6aac687b7305ae6f4"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/43xxx/CVE-2026-43006.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-43006"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"8622b20f23ed165f48b8ca61503a107d17f8d585"},{"fixed":"040a1e7e0e2f01851fec1dd2d96906f8636a9f75"},{"fixed":"40170fc1a79c1b2e68f09ae6aac687b7305ae6f4"},{"fixed":"111a12b422a8cfa93deabaef26fec48237163214"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43006.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.15.0"},{"fixed":"6.18.22"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"6.19.12"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-43006.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H"}]}