{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-63804",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-19T07:54:57.013Z",
        "datePublished": "2026-07-19T12:02:09.111Z",
        "dateUpdated": "2026-08-17T04:51:09.991Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-08-17T04:51:09.991Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ngfs2: fix use-after-free in gfs2_qd_dealloc\n\ngfs2_qd_dealloc(), called as an RCU callback from gfs2_qd_dispose(),\naccesses the superblock object sdp through qd->qd_sbd after freeing qd.\nIt does so to decrement sd_quota_count and wake up sd_kill_wait.\n\nHowever, by the time the RCU callback runs, gfs2_put_super() may have\nalready freed sdp via free_sbd().  This can happen when\ngfs2_quota_cleanup() is called during unmount: it disposes of quota\nobjects via call_rcu() and then waits on sd_kill_wait with a 60-second\ntimeout.  If the timeout expires, or if gfs2_gl_hash_clear() triggers\nadditional qd_put() calls that schedule more RCU callbacks after the\nwait completes, gfs2_put_super() will proceed to free the superblock\nwhile RCU callbacks referencing it are still pending.\n\nAdd an rcu_barrier() before free_sbd() in gfs2_put_super() to ensure\nall pending RCU callbacks (including gfs2_qd_dealloc) have completed\nbefore the superblock is freed."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "fs/gfs2/super.c"
                    ],
                    "versions": [
                        {
                            "version": "a475c5dd16e57c570113eccba51955b5df8bb052",
                            "lessThan": "4fe388218826df8607ae41a6305df67db08a9093",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "a475c5dd16e57c570113eccba51955b5df8bb052",
                            "lessThan": "8745d9f7e1682c39f0a1578895ac74205e2a6757",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "a475c5dd16e57c570113eccba51955b5df8bb052",
                            "lessThan": "b85ef03f726b15047a6fa6d11b639bdf6c0ee4f0",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "a475c5dd16e57c570113eccba51955b5df8bb052",
                            "lessThan": "9d0d5ba20cad661f7f287d4c66d2c19022ce2fd0",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "a475c5dd16e57c570113eccba51955b5df8bb052",
                            "lessThan": "f9c9ec2c319f843b70ecdf939d48b52d189bc081",
                            "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/gfs2/super.c"
                    ],
                    "versions": [
                        {
                            "version": "6.6",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.6",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.6.144",
                            "lessThanOrEqual": "6.6.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.95",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.38",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1.3",
                            "lessThanOrEqual": "7.1.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.2",
                            "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": "6.6",
                                    "versionEndExcluding": "6.6.144"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.6",
                                    "versionEndExcluding": "6.12.95"
                                },
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                                    "versionStartIncluding": "6.6",
                                    "versionEndExcluding": "6.18.38"
                                },
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                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.6",
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                                },
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                                    "vulnerable": true,
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                                    "versionStartIncluding": "6.6",
                                    "versionEndExcluding": "7.2"
                                }
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            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/4fe388218826df8607ae41a6305df67db08a9093"
                },
                {
                    "url": "https://git.kernel.org/stable/c/8745d9f7e1682c39f0a1578895ac74205e2a6757"
                },
                {
                    "url": "https://git.kernel.org/stable/c/b85ef03f726b15047a6fa6d11b639bdf6c0ee4f0"
                },
                {
                    "url": "https://git.kernel.org/stable/c/9d0d5ba20cad661f7f287d4c66d2c19022ce2fd0"
                },
                {
                    "url": "https://git.kernel.org/stable/c/f9c9ec2c319f843b70ecdf939d48b52d189bc081"
                }
            ],
            "title": "gfs2: fix use-after-free in gfs2_qd_dealloc",
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}