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    "cveMetadata": {
        "cveId": "CVE-2021-47608",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2024-05-24T15:11:00.737Z",
        "datePublished": "2024-06-19T14:54:06.388Z",
        "dateUpdated": "2026-05-11T13:57:50.154Z"
    },
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                "dateUpdated": "2026-05-11T13:57:50.154Z"
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            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nbpf: Fix kernel address leakage in atomic fetch\n\nThe change in commit 37086bfdc737 (\"bpf: Propagate stack bounds to registers\nin atomics w/ BPF_FETCH\") around check_mem_access() handling is buggy since\nthis would allow for unprivileged users to leak kernel pointers. For example,\nan atomic fetch/and with -1 on a stack destination which holds a spilled\npointer will migrate the spilled register type into a scalar, which can then\nbe exported out of the program (since scalar != pointer) by dumping it into\na map value.\n\nThe original implementation of XADD was preventing this situation by using\na double call to check_mem_access() one with BPF_READ and a subsequent one\nwith BPF_WRITE, in both cases passing -1 as a placeholder value instead of\nregister as per XADD semantics since it didn't contain a value fetch. The\nBPF_READ also included a check in check_stack_read_fixed_off() which rejects\nthe program if the stack slot is of __is_pointer_value() if dst_regno < 0.\nThe latter is to distinguish whether we're dealing with a regular stack spill/\nfill or some arithmetical operation which is disallowed on non-scalars, see\nalso 6e7e63cbb023 (\"bpf: Forbid XADD on spilled pointers for unprivileged\nusers\") for more context on check_mem_access() and its handling of placeholder\nvalue -1.\n\nOne minimally intrusive option to fix the leak is for the BPF_FETCH case to\ninitially check the BPF_READ case via check_mem_access() with -1 as register,\nfollowed by the actual load case with non-negative load_reg to propagate\nstack bounds to registers."
                }
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                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "kernel/bpf/verifier.c"
                    ],
                    "versions": [
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                            "version": "37086bfdc737ea6f66bf68dcf16757004d68e1e1",
                            "lessThan": "423628125a484538111c2c6d9bb1588eb086053b",
                            "status": "affected",
                            "versionType": "git"
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                            "version": "37086bfdc737ea6f66bf68dcf16757004d68e1e1",
                            "lessThan": "7d3baf0afa3aa9102d6a521a8e4c41888bb79882",
                            "status": "affected",
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                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
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                            "status": "affected"
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                        {
                            "version": "0",
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                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.15.11",
                            "lessThanOrEqual": "5.15.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "5.16",
                            "lessThanOrEqual": "*",
                            "status": "unaffected",
                            "versionType": "original_commit_for_fix"
                        }
                    ]
                }
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                    "url": "https://git.kernel.org/stable/c/423628125a484538111c2c6d9bb1588eb086053b"
                },
                {
                    "url": "https://git.kernel.org/stable/c/7d3baf0afa3aa9102d6a521a8e4c41888bb79882"
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