{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-63796", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T07:54:57.012Z", "datePublished": "2026-07-19T12:02:04.634Z", "dateUpdated": "2026-07-20T13:40:07.618Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-07-20T13:40:07.618Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: reject oversized group bitmap descriptors\n\nocfs2_validate_gd_parent() only bounds bg_bits against the parent\nallocator's chain geometry. A malicious descriptor can still claim a\nbg_size/bg_bits pair that exceeds the bitmap bytes that physically fit in\nthe group descriptor block, so later bitmap scans and bit updates can run\npast bg_bitmap.\n\nAdd a physical-cap check based on ocfs2_group_bitmap_size() for the parent\nallocator type and reject descriptors whose bg_size or bg_bits exceed that\ncapacity. Keep the existing chain geometry check so both the on-disk\nbitmap layout and the allocator metadata must agree before the descriptor\nis used.\n\nValidation reproduced this kernel report:\nKASAN use-after-free in _find_next_bit+0x7f/0xc0\nRead of size 8\nCall trace:\n dump_stack_lvl+0x66/0xa0 (?:?)\n print_report+0xd0/0x630 (?:?)\n _find_next_bit+0x7f/0xc0 (?:?)\n srso_alias_return_thunk+0x5/0xfbef5 (?:?)\n __virt_addr_valid+0x188/0x2f0 (?:?)\n kasan_report+0xe4/0x120 (?:?)\n ocfs2_find_max_contig_free_bits+0x35/0x70 (fs/ocfs2/suballoc.c:1375)\n ocfs2_block_group_set_bits+0x472/0x4b0 (fs/ocfs2/suballoc.c:1457)\n ocfs2_cluster_group_search+0x16b/0x440 (fs/ocfs2/suballoc.c:86)\n ocfs2_bg_discontig_fix_result+0x1ef/0x230 (fs/ocfs2/suballoc.c:1786)\n ocfs2_search_chain+0x8f8/0x10a0 (fs/ocfs2/suballoc.c:1886)\n get_page_from_freelist+0x70e/0x2370 (?:?)\n lock_release+0xc6/0x290 (?:?)\n do_raw_spin_unlock+0x9a/0x100 (?:?)\n kasan_unpoison+0x27/0x60 (?:?)\n __bfs+0x147/0x240 (?:?)\n get_page_from_freelist+0x83d/0x2370 (?:?)\n ocfs2_claim_suballoc_bits+0x38c/0xe70 (fs/ocfs2/suballoc.c:96)\n sched_domains_numa_masks_clear+0x70/0xd0 (?:?)\n check_irq_usage+0xe8/0xb70 (?:?)\n __ocfs2_claim_clusters+0x18d/0x4c0 (fs/ocfs2/suballoc.c:2497)\n check_path+0x24/0x50 (?:?)\n rcu_is_watching+0x20/0x50 (?:?)\n check_prev_add+0xfd/0xd00 (?:?)\n ocfs2_add_clusters_in_btree+0x17d/0x810 (fs/ocfs2/suballoc.c:?)\n __folio_batch_add_and_move+0x1f5/0x3d0 (?:?)\n ocfs2_add_inode_data+0xd9/0x120 (fs/ocfs2/suballoc.c:?)\n filemap_add_folio+0x105/0x1f0 (?:?)\n ocfs2_write_begin_nolock+0x29f7/0x2f80 (fs/ocfs2/suballoc.c:3043)\n ocfs2_read_inode_block+0xb5/0x110 (fs/ocfs2/suballoc.c:?)\n down_write+0xf5/0x180 (?:?)\n ocfs2_write_begin+0x180/0x240 (fs/ocfs2/suballoc.c:?)\n __mark_inode_dirty+0x758/0x9a0 (?:?)\n inode_to_bdi+0x41/0x90 (?:?)\n balance_dirty_pages_ratelimited_flags+0xf8/0x1d0 (?:?)\n generic_perform_write+0x252/0x440 (?:?)\n mnt_put_write_access_file+0x16/0x70 (?:?)\n file_update_time_flags+0xe4/0x200 (?:?)\n ocfs2_file_write_iter+0x80a/0x1320 (fs/ocfs2/suballoc.c:?)\n lock_acquire+0x184/0x2f0 (?:?)\n ksys_write+0xd2/0x170 (?:?)\n apparmor_file_permission+0xf5/0x310 (?:?)\n read_zero+0x8d/0x140 (?:?)\n lock_is_held_type+0x8f/0x100 (?:?)"}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH"}}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["fs/ocfs2/suballoc.c"], "versions": [{"version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c", "lessThan": "336340a0f8a141df8a4eb21a5a86f8ffb87769f6", "status": "affected", "versionType": "git"}, {"version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c", "lessThan": "296c6a42b1174395935ca4cfe8f393e37b698d54", "status": "affected", "versionType": "git"}, {"version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c", "lessThan": "d2cd59fa848f9f13796ef214d3b1b5ca9a3fe21e", "status": "affected", "versionType": "git"}, {"version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c", "lessThan": "c5a125eadba05ba421c4b55e68da22b4a40d32b4", "status": "affected", "versionType": "git"}, {"version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c", "lessThan": "8f9903b0cdbb3155a8899410330b4b4d583a7a5c", "status": "affected", "versionType": "git"}, {"version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c", "lessThan": "4cd57ebee395041099fcdfcabb00749ce38d8b27", "status": "affected", "versionType": "git"}, {"version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c", "lessThan": "99c21e7263248c3f084756bfae08163cc5d6c62f", "status": "affected", "versionType": "git"}, {"version": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c", "lessThan": "9bd541e09dffff27e5bec0f9f45b0228173a5375", "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/ocfs2/suballoc.c"], "versions": [{"version": "2.6.16", "status": "affected"}, {"version": "0", "lessThan": "2.6.16", "status": "unaffected", "versionType": "semver"}, {"version": "5.10.260", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver"}, {"version": "5.15.211", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.177", "lessThanOrEqual": "6.1.*", "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-rc1", "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": "2.6.16", "versionEndExcluding": "5.10.260"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "5.15.211"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "6.1.177"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "6.6.144"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "6.12.95"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "6.18.38"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "7.1.3"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.16", "versionEndExcluding": "7.2-rc1"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/336340a0f8a141df8a4eb21a5a86f8ffb87769f6"}, {"url": "https://git.kernel.org/stable/c/296c6a42b1174395935ca4cfe8f393e37b698d54"}, {"url": "https://git.kernel.org/stable/c/d2cd59fa848f9f13796ef214d3b1b5ca9a3fe21e"}, {"url": "https://git.kernel.org/stable/c/c5a125eadba05ba421c4b55e68da22b4a40d32b4"}, {"url": "https://git.kernel.org/stable/c/8f9903b0cdbb3155a8899410330b4b4d583a7a5c"}, {"url": "https://git.kernel.org/stable/c/4cd57ebee395041099fcdfcabb00749ce38d8b27"}, {"url": "https://git.kernel.org/stable/c/99c21e7263248c3f084756bfae08163cc5d6c62f"}, {"url": "https://git.kernel.org/stable/c/9bd541e09dffff27e5bec0f9f45b0228173a5375"}], "title": "ocfs2: reject oversized group bitmap descriptors", "x_generator": {"engine": "bippy-1.2.0"}}}}

{}

{}

{"bugzilla": {"description": "kernel: ocfs2: reject oversized group bitmap descriptors", "id": "2502205", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2502205"}, "csaw": false, "cwe": "CWE-825", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nocfs2: reject oversized group bitmap descriptors\nocfs2_validate_gd_parent() only bounds bg_bits against the parent\nallocator's chain geometry. A malicious descriptor can still claim a\nbg_size/bg_bits pair that exceeds the bitmap bytes that physically fit in\nthe group descriptor block, so later bitmap scans and bit updates can run\npast bg_bitmap.\nAdd a physical-cap check based on ocfs2_group_bitmap_size() for the parent\nallocator type and reject descriptors whose bg_size or bg_bits exceed that\ncapacity. Keep the existing chain geometry check so both the on-disk\nbitmap layout and the allocator metadata must agree before the descriptor\nis used.\nValidation reproduced this kernel report:\nKASAN use-after-free in _find_next_bit+0x7f/0xc0\nRead of size 8\nCall trace:\ndump_stack_lvl+0x66/0xa0 (?:?)\nprint_report+0xd0/0x630 (?:?)\n_find_next_bit+0x7f/0xc0 (?:?)\nsrso_alias_return_thunk+0x5/0xfbef5 (?:?)\n__virt_addr_valid+0x188/0x2f0 (?:?)\nkasan_report+0xe4/0x120 (?:?)\nocfs2_find_max_contig_free_bits+0x35/0x70 (fs/ocfs2/suballoc.c:1375)\nocfs2_block_group_set_bits+0x472/0x4b0 (fs/ocfs2/suballoc.c:1457)\nocfs2_cluster_group_search+0x16b/0x440 (fs/ocfs2/suballoc.c:86)\nocfs2_bg_discontig_fix_result+0x1ef/0x230 (fs/ocfs2/suballoc.c:1786)\nocfs2_search_chain+0x8f8/0x10a0 (fs/ocfs2/suballoc.c:1886)\nget_page_from_freelist+0x70e/0x2370 (?:?)\nlock_release+0xc6/0x290 (?:?)\ndo_raw_spin_unlock+0x9a/0x100 (?:?)\nkasan_unpoison+0x27/0x60 (?:?)\n__bfs+0x147/0x240 (?:?)\nget_page_from_freelist+0x83d/0x2370 (?:?)\nocfs2_claim_suballoc_bits+0x38c/0xe70 (fs/ocfs2/suballoc.c:96)\nsched_domains_numa_masks_clear+0x70/0xd0 (?:?)\ncheck_irq_usage+0xe8/0xb70 (?:?)\n__ocfs2_claim_clusters+0x18d/0x4c0 (fs/ocfs2/suballoc.c:2497)\ncheck_path+0x24/0x50 (?:?)\nrcu_is_watching+0x20/0x50 (?:?)\ncheck_prev_add+0xfd/0xd00 (?:?)\nocfs2_add_clusters_in_btree+0x17d/0x810 (fs/ocfs2/suballoc.c:?)\n__folio_batch_add_and_move+0x1f5/0x3d0 (?:?)\nocfs2_add_inode_data+0xd9/0x120 (fs/ocfs2/suballoc.c:?)\nfilemap_add_folio+0x105/0x1f0 (?:?)\nocfs2_write_begin_nolock+0x29f7/0x2f80 (fs/ocfs2/suballoc.c:3043)\nocfs2_read_inode_block+0xb5/0x110 (fs/ocfs2/suballoc.c:?)\ndown_write+0xf5/0x180 (?:?)\nocfs2_write_begin+0x180/0x240 (fs/ocfs2/suballoc.c:?)\n__mark_inode_dirty+0x758/0x9a0 (?:?)\ninode_to_bdi+0x41/0x90 (?:?)\nbalance_dirty_pages_ratelimited_flags+0xf8/0x1d0 (?:?)\ngeneric_perform_write+0x252/0x440 (?:?)\nmnt_put_write_access_file+0x16/0x70 (?:?)\nfile_update_time_flags+0xe4/0x200 (?:?)\nocfs2_file_write_iter+0x80a/0x1320 (fs/ocfs2/suballoc.c:?)\nlock_acquire+0x184/0x2f0 (?:?)\nksys_write+0xd2/0x170 (?:?)\napparmor_file_permission+0xf5/0x310 (?:?)\nread_zero+0x8d/0x140 (?:?)\nlock_is_held_type+0x8f/0x100 (?:?)", "A flaw was found in the Linux kernel's Oracle Cluster File System 2 (ocfs2). A local attacker could craft a malicious group bitmap descriptor that claims a size exceeding the physically allocated bitmap bytes. This improper input validation allows subsequent operations to read or write beyond the intended memory region, leading to a use-after-free vulnerability. This can result in a system crash (denial of service) or potentially lead to arbitrary code execution."], "name": "CVE-2026-63796", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not 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"}, {"cpe": "cpe:/a:redhat:hummingbird:1", "fix_state": "Not affected", "impact": "important", "package_name": "erlang27", "product_name": "Red Hat Hardened Images"}], "public_date": "2026-07-19T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-63796\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-63796\nhttps://lore.kernel.org/linux-cve-announce/2026071900-CVE-2026-63796-9a88@gregkh/T"]}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccd979bdbce9fba8412beb3f1de68a9d0171b12c,336340a0f8a141df8a4eb21a5a86f8ffb87769f6)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccd979bdbce9fba8412beb3f1de68a9d0171b12c,296c6a42b1174395935ca4cfe8f393e37b698d54)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccd979bdbce9fba8412beb3f1de68a9d0171b12c,d2cd59fa848f9f13796ef214d3b1b5ca9a3fe21e)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccd979bdbce9fba8412beb3f1de68a9d0171b12c,c5a125eadba05ba421c4b55e68da22b4a40d32b4)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccd979bdbce9fba8412beb3f1de68a9d0171b12c,8f9903b0cdbb3155a8899410330b4b4d583a7a5c)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccd979bdbce9fba8412beb3f1de68a9d0171b12c,4cd57ebee395041099fcdfcabb00749ce38d8b27)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccd979bdbce9fba8412beb3f1de68a9d0171b12c,99c21e7263248c3f084756bfae08163cc5d6c62f)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[ccd979bdbce9fba8412beb3f1de68a9d0171b12c,9bd541e09dffff27e5bec0f9f45b0228173a5375)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "2.6.16"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[0,2.6.16)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.10.260,5.11.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[5.15.211,5.16.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.1.177,6.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.144,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.95,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.38,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.3,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2-rc1,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-07-21T12:00:05.501233+00:00", "updated": "2026-07-21T12:00:05.501275+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"]}