{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-89829", "modified": "2026-10-09T11:39:44Z", "upstream": [ "CVE-2026-89829" ], "published": "2026-09-16T10:32:03Z", "summary": "f2fs: fix to pass folio->index to f2fs_sanity_check_node_footer()", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to pass folio->index to f2fs_sanity_check_node_footer()\n\nOtherwise in f2fs_sanity_check_node_footer(), it will check the\nsame nid incorrectly.", "severity": [ { "type": "CVSS_V3", "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H" } ], "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:13", "name": "linux" }, "versions": [ "1:6.18.29-1+rpt1", "1:6.18.33-1+rpt1", "1:6.18.34-1+rpt1", "1:6.18.39-1+rpt1", "1:6.18.50-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.18.29+rpt-rpi-2712", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v6", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v7", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-2712", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v6", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v7", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-2712", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v6", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v7", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-2712", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v6", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v7", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.39+rpt-rpi-v8-rt", "binary_version": "1:6.18.39-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-2712", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v6", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v7", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8", "binary_version": "1:6.18.50-1+rpt1" }, { "binary_name": "linux-image-6.18.50+rpt-rpi-v8-rt", "binary_version": "1:6.18.50-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.18.29-1+rpt1": { "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc", "upstream_version": "6.18.29", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.51" }, "1:6.18.33-1+rpt1": { "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412", "upstream_version": "6.18.33", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.51" }, "1:6.18.34-1+rpt1": { "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af", "upstream_version": "6.18.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.51" }, "1:6.18.39-1+rpt1": { "linux_commit": "60ea684a8ace97bb0db1a16e20753bdd6ab371ff", "upstream_version": "6.18.39", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.51" }, "1:6.18.50-1+rpt1": { "linux_commit": "cff533aec2fa601846766b32ff57204e0a61bed7", "upstream_version": "6.18.50", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.51" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-89829" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/a984446aa9d5b787afa3023fc7b44017b80fe3bc" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/0b196c07407f48a41cd9741cf53e10cb1e23d2e5" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/7e188e9f9437ab47c3237d609f1b26348d6fea1a" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-09-16T14:40:32Z", "severity": { "source": "kernel CNA", "cvss_v3_score": 7.8, "cvss_v3_severity": "High", "scenario": "AV:L - The defect is in f2fs __write_node_folio() on the node-mapping writeback path, reached only from local VFS operations (fsync, write, checkpoint, GC, or reclaim) on a mounted f2fs volume; no network protocol (ksmbd/nfsd/packet) processes this node-footer check.\nAC:L - A crafted f2fs image fully controls the on-disk node footer nid. Related syzbot reports show that async node readahead of a fuzzed image followed by writeback deterministically hits the mismatched-nid case, with no race or layout the attacker cannot arrange.\nPR:L - Mounting f2fs requires privilege (no FS_USERNS_MOUNT), but once the volume is mounted\u2014Android userdata, automounted SD/USB, or a shared workstation\u2014any unprivileged local user can dirty node pages via write/fsync/fallocate/truncate and enter __write_node_folio with no capability check.\nUI:N - After the crafted image is mounted, the attacker triggers node writeback themselves through ordinary file syscalls or in-kernel checkpoint/reclaim; no separate victim action such as opening a file or confirming a prompt is required.\nS:U - The impact is kernel memory and f2fs metadata corruption on the host that mounted the volume; it does not cross a VM, IOMMU, or guest-to-host security boundary.\nC:H - __write_node_folio uses the attacker-controlled footer nid as the NAT key without a range check, so current_nat_addr() indexes nat_bitmap at an attacker-chosen offset (nid/NAT_ENTRY_PER_BLOCK), an unbounded out-of-bounds kernel read. The same nid confusion later parses the planted node with the wrong layout, leaking adjacent folio contents as in CVE-2025-40025.\nI:H - set_node_addr() and f2fs_do_write_node_page() commit the node folio under the footer nid, overwriting an arbitrary NAT entry and remapping any node. Subsequent operations on that nid write through the wrong inode-vs-dnode layout, producing out-of-bounds metadata writes past the node folio.\nA:H - A mismatched nid that fails f2fs_get_node_info() takes redirty_out, looping writepages indefinitely (the hang this check was added to stop). A nid that proceeds hits f2fs_bug_on() in set_node_addr()/write_end_io, panicking with CONFIG_F2FS_CHECK_FS or WARNing and corrupting the filesystem otherwise." } } }