{"id":"CVE-2021-47040","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix overflows checks in provide buffers\n\nColin reported before possible overflow and sign extension problems in\nio_provide_buffers_prep()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix overflows checks in provide buffers\n\nColin reported before possible overflow and sign extension problems in\nio_provide_buffers_prep(). As Linus pointed ou…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-120"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.8, < 5.10.37","linux_kernel >= 5.11, < 5.11.21","linux_kernel >= 5.12, < 5.12.4"],"patched":["linux_kernel 5.12.4"],"published":"2024-02-28","updated":"2026-08-04","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2021-47040","references":[{"url":"https://git.kernel.org/stable/c/38134ada0ceea3e848fe993263c0ff6207fd46e7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/51bf90901952aaac564bbdb36b2b503050c53dd9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/84b8c266c4bfe9ed5128e13253c388deb74b1b03","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cbbc13b115b8f18e0a714d89f87fbdc499acfe2d","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/38134ada0ceea3e848fe993263c0ff6207fd46e7","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/51bf90901952aaac564bbdb36b2b503050c53dd9","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/84b8c266c4bfe9ed5128e13253c388deb74b1b03","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/cbbc13b115b8f18e0a714d89f87fbdc499acfe2d","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.0026,"epssPercentile":0.17996,"ingestedAt":"2026-08-04T10:39:39.508Z","slug":"CVE-2021-47040","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nio_uring: fix overflows checks in provide buffers\n\nColin reported before possible overflow and sign extension problems in\nio_provide_buffers_prep(). As Linus pointed out previous attempt did nothing\nuseful, see d81269fecb8ce (\"io_uring: fix provide_buffers sign extension\").\n\nDo that with help of check_<op>_overflow helpers. And fix struct\nio_provide_buf::len type, as it doesn't make much sense to keep it\nsigned.\n\n## Affected\n\n- `linux_kernel >= 5.8, < 5.10.37`\n- `linux_kernel >= 5.11, < 5.11.21`\n- `linux_kernel >= 5.12, < 5.12.4`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 5.12.4`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}