Bugzilla – Bug 1262657
VUL-0: CVE-2026-31463: kernel: iomap: fix invalid folio access when i_blkbits differs from I/O granularity
Last modified: 2026-04-24 04:45:11 UTC
In the Linux kernel, the following vulnerability has been resolved: iomap: fix invalid folio access when i_blkbits differs from I/O granularity Commit aa35dd5cbc06 ("iomap: fix invalid folio access after folio_end_read()") partially addressed invalid folio access for folios without an ifs attached, but it did not handle the case where 1 << inode->i_blkbits matches the folio size but is different from the granularity used for the IO, which means IO can be submitted for less than the full folio for the !ifs case. In this case, the condition: if (*bytes_submitted == folio_len) ctx->cur_folio = NULL; in iomap_read_folio_iter() will not invalidate ctx->cur_folio, and iomap_read_end() will still be called on the folio even though the IO helper owns it and will finish the read on it. Fix this by unconditionally invalidating ctx->cur_folio for the !ifs case. References: http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2026-31463 https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-31463.mbox https://git.kernel.org/stable/c/4a927f670cdb0def226f9f85f42a9f19d9e09c88 https://git.kernel.org/stable/c/bd71fb3fea9945987053968f028a948997cba8cc https://www.cve.org/CVERecord?id=CVE-2026-31463 https://bugzilla.redhat.com/show_bug.cgi?id=2460670