{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-53165",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-06-09T07:44:35.389Z",
        "datePublished": "2026-06-25T08:38:45.445Z",
        "dateUpdated": "2026-08-05T12:33:38.251Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-05T12:33:38.251Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niomap: avoid potential null folio->mapping deref during error reporting\n\nWhen a buffered read fails, iomap_finish_folio_read() reports the error\nwith fserror_report_io(folio->mapping->host, ...). This is called after\nifs->read_bytes_pending has been decremented by the bytes attempted to\nbe read.\n\nFor a folio split across multiple read completions, the folio is only\nguaranteed to stay locked while read_bytes_pending > 0. Once\niomap_finish_folio_read() decrements read_bytes_pending, another\nin-flight read can complete and end the read on the folio, which unlocks\nit. This allows truncate logic to run and detach the folio (set\nfolio->mapping to NULL). The error reporting path then can dereference a\nNULL folio->mapping. As reported by Sam Sun, this is the race that can\noccur:\n\nCPU0: failed completion      CPU1: final completion     CPU2: truncate\n-----------------------      ----------------------     --------------\nread_bytes_pending -= len\nfinished = false\n/* preempted before\n   fserror_report_io() */\n\t\t\t     read_bytes_pending -= len\n\t\t\t     finished = true\n\t\t\t     folio_end_read()\n\t\t\t\t\t\t\ttruncate clears\n\t\t\t\t\t\t\tfolio->mapping\nfserror_report_io(\n  folio->mapping->host, ...)\n\t      ^ NULL deref\n\nFix this by reporting the error first before decrementing\nifs->read_bytes_pending."
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH"
                    },
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "AV:N - Remote file-serving paths such as ksmbd and nfsd can drive VFS reads and truncates on iomap-backed filesystems, reaching the vulnerable completion path through network requests. A local syscall path also exists, but the highest reasonable exposure is a writable network share/export.\nAC:L - The bug is a race, but an attacker can issue concurrent read/readahead and truncate or size-change operations and retry the window. There is no memory-layout prerequisite, and uncertainty is resolved toward the higher-severity AC:L.\nPR:N - A writable anonymous or guest SMB/NFS export can expose the read and truncate operations without prior authentication. If the export requires credentials this would be PR:L, but the highest reasonable deployment is unauthenticated access.\nUI:N - The attacker can trigger both the read/error-reporting side and the truncate side directly through requests. No separate victim action is required.\nS:U - The fault occurs within the kernel filesystem/page-cache security authority. It does not cross a VM, IOMMU, or sandbox boundary.\nC:N - The vulnerable dereference is a NULL folio->mapping dereference during error reporting. This is a crash condition, not an information disclosure primitive.\nI:N - The bug does not corrupt attacker-controlled memory or provide a write primitive. It only dereferences a NULL mapping pointer.\nA:H - A NULL pointer dereference in kernel context can oops or panic the system. Repeated triggering can deny availability of the affected host."
                        }
                    ]
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/iomap/buffered-io.c"
                    ],
                    "versions": [
                        {
                            "version": "a9d573ee88af980f14fdadb5c12bbf6a195fb3f1",
                            "lessThan": "1ad453817a4077230d1ba88eb0868f05f824449a",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "a9d573ee88af980f14fdadb5c12bbf6a195fb3f1",
                            "lessThan": "2eea7f44b9c8b42fd7d3a1a87c06a7cd1b99c327",
                            "status": "affected",
                            "versionType": "git"
                        }
                    ]
                },
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "affected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/iomap/buffered-io.c"
                    ],
                    "versions": [
                        {
                            "version": "7.0",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "7.0",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.13",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
            ],
            "cpeApplicability": [
                {
                    "nodes": [
                        {
                            "operator": "OR",
                            "negate": false,
                            "cpeMatch": [
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.0",
                                    "versionEndExcluding": "7.0.13"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "7.0",
                                    "versionEndExcluding": "7.1"
                                }
                            ]
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/1ad453817a4077230d1ba88eb0868f05f824449a"
                },
                {
                    "url": "https://git.kernel.org/stable/c/2eea7f44b9c8b42fd7d3a1a87c06a7cd1b99c327"
                }
            ],
            "title": "iomap: avoid potential null folio->mapping deref during error reporting",
            "x_generator": {
                "engine": "bippy-1.2.0"
            }
        }
    }
}