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{"bugzilla": {"description": "kernel: selinux: fix NULL-pointer dereference when hashtab allocation fails", "id": "2274568", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2274568"}, "csaw": false, "cvss3": {"cvss3_base_score": "4.4", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "status": "draft"}, "cwe": "CWE-476", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nselinux: fix NULL-pointer dereference when hashtab allocation fails\nWhen the hash table slot array allocation fails in hashtab_init(),\nh->size is left initialized with a non-zero value, but the h->htable\npointer is NULL. This may then cause a NULL pointer dereference, since\nthe policydb code relies on the assumption that even after a failed\nhashtab_init(), hashtab_map() and hashtab_destroy() can be safely called\non it. Yet, these detect an empty hashtab only by looking at the size.\nFix this by making sure that hashtab_init() always leaves behind a valid\nempty hashtab when the allocation fails.", "A vulnerability was found in the Linux kernel, related to SELinux. This issue occurs when a hash table allocation fails during the hashtab_init() function. When this failure happens, the system leaves the hash table (h->size) initialized with a non-zero value, but the h->htable pointer remains null. This can result in a null pointer dereference when SELinux's policy database tries to use the hash table, relying on the assumption that it is valid. This situation can cause system crashes or unexpected behavior."], "name": "CVE-2021-47218", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Out of support scope", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2024-04-10T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2021-47218\nhttps://nvd.nist.gov/vuln/detail/CVE-2021-47218\nhttps://lore.kernel.org/linux-cve-announce/2024041006-CVE-2021-47218-cdc8@gregkh/T"], "statement": "The fix for this issue ensures that even in the case of allocation failure, hashtab_init() leaves behind a valid empty hash table, preventing the null pointer dereference and improving the stability of SELinux in this context\u200b", "threat_severity": "Moderate"}

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