{"id":"CVE-2026-46124","summary":"isofs: validate block number from NFS file handle in isofs_export_iget","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nisofs: validate block number from NFS file handle in isofs_export_iget\n\nisofs_fh_to_dentry() and isofs_fh_to_parent() pass an attacker-\ncontrolled block number (ifid-\u003eblock or ifid-\u003eparent_block) from\nthe NFS file handle to isofs_export_iget(), which only rejects\nblock == 0 before calling isofs_iget() and ultimately sb_bread().\nA crafted file handle with fh_len sufficient to pass the check\nadded by commit 0405d4b63d08 (\"isofs: Prevent the use of too small\nfid\") can still drive the server to read any in-range block on the\nbacking device as if it were an iso_directory_record.  That earlier\nfix was assigned CVE-2025-37780.\n\nsb_bread() on an out-of-range block returns NULL cleanly via the\nEIO path, so there is no memory-safety violation.  For in-range\nreads of adjacent-partition data on the same block device, the\nunrelated bytes end up in iso_inode_info fields that reach the NFS\nclient as dentry metadata.  The deployment surface (isofs exported\nover NFS from loop-mounted images) is narrow and requires an\nauthenticated NFS peer, but the malformed-file-handle class is\nreportable as hardening next to the existing CVE-2025-37780 fix.\n\nReject block \u003e= ISOFS_SB(sb)-\u003es_nzones in isofs_export_iget() so\nthe check covers both isofs_fh_to_dentry() and isofs_fh_to_parent()\ncall sites with a single line.","modified":"2026-10-28T02:30:43.913020510Z","published":"2026-05-28T09:35:38.887Z","related":["SUSE-SU-2026:22521-1","SUSE-SU-2026:22522-1","SUSE-SU-2026:22665-1","SUSE-SU-2026:22666-1","SUSE-SU-2026:22742-1","SUSE-SU-2026:22769-1","SUSE-SU-2026:22812-1","SUSE-SU-2026:22835-1","SUSE-SU-2026:2799-1","SUSE-SU-2026:2800-1","SUSE-SU-2026:2914-1","openSUSE-SU-2026:10954-1","openSUSE-SU-2026:21388-1"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46124.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://cert-portal.siemens.com/productcert/html/ssa-784472.html"},{"type":"WEB","url":"https://git.kernel.org/stable/c/0a1af74ae2177bda3aee0837a0546309aa539d0d"},{"type":"WEB","url":"https://git.kernel.org/stable/c/24376458138387fb251e782e624c7776e9826796"},{"type":"WEB","url":"https://git.kernel.org/stable/c/31dbb4ba0f719ae7774e4c0c95172c9bf81692f5"},{"type":"WEB","url":"https://git.kernel.org/stable/c/4c721a1d9b3c4fcaf59cc9b2281e3ec5a043e1a6"},{"type":"WEB","url":"https://git.kernel.org/stable/c/908a76f0b1038035e6ebb4f2293ce079f92e0a02"},{"type":"WEB","url":"https://git.kernel.org/stable/c/afbafeddf23db13fe2edb2d5c0bf4bbb13d7881b"},{"type":"WEB","url":"https://git.kernel.org/stable/c/bb0988ed4f2e26d59bbb58f644cb3a55b7521e21"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ee0024f5a7e3c73aa253869fae9650ae054093ca"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/46xxx/CVE-2026-46124.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-46124"},{"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":"5e7de55602c61c8ff28db075cc49c8dd6989d7e0"},{"fixed":"ee0024f5a7e3c73aa253869fae9650ae054093ca"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"63d5a3e207bf315a32c7d16de6c89753a759f95a"},{"fixed":"31dbb4ba0f719ae7774e4c0c95172c9bf81692f5"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0fdafdaef796816a9ed0fd7ac812932d569d9beb"},{"fixed":"908a76f0b1038035e6ebb4f2293ce079f92e0a02"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"952e7a7e317f126d0a2b879fc531b716932d5ffa"},{"fixed":"bb0988ed4f2e26d59bbb58f644cb3a55b7521e21"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"56dfffea9fd3be0b3795a9ca6401e133a8427e0b"},{"fixed":"0a1af74ae2177bda3aee0837a0546309aa539d0d"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0405d4b63d082861f4eaff9d39c78ee9dc34f845"},{"fixed":"afbafeddf23db13fe2edb2d5c0bf4bbb13d7881b"},{"fixed":"4c721a1d9b3c4fcaf59cc9b2281e3ec5a043e1a6"},{"fixed":"24376458138387fb251e782e624c7776e9826796"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.10.237"},{"fixed":"5.10.258"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.15.181"},{"fixed":"5.15.209"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.1.135"},{"fixed":"6.1.175"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.6.88"},{"fixed":"6.6.140"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.12.25"},{"fixed":"6.12.88"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"5.4.293"},{"fixed":"5.5"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"6.14.4"},{"fixed":"6.15"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ee01a309ebf598be1ff8174901ed6e91619f1749"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"007124c896e7d4614ac1f6bd4dedb975c35a2a8e"}]}],"versions":["v5.10.257","v5.10.256","v5.10.255","v5.10.254","v5.10.253","v5.10.252","v5.10.251","v5.10.250","v5.10.249","v5.10.248","v5.10.247","v5.10.246","v5.10.245","v5.10.244","v5.10.243","v5.10.242","v5.10.241","v5.10.240","v5.10.239","v5.10.238","v5.10.237","v5.15.208","v5.15.207","v5.15.206","v5.15.205","v5.15.204","v5.15.203","v5.15.202","v5.15.201","v5.15.200","v5.15.199","v5.15.198","v5.15.197","v5.15.196","v5.15.195","v5.15.194","v5.15.193","v5.15.192","v5.15.191","v5.15.190","v5.15.189","v5.15.188","v5.15.187","v5.15.186","v5.15.185","v5.15.184","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