{"cve":{"cve_id":"CVE-2026-53040","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":null,"epss_percentile":null,"epss_as_of":null,"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate bg_bits during freefrag scan\n\n[BUG]\nA crafted filesystem can trigger an out-of-bounds bitmap walk when\nOCFS2_IOC_INFO is issued with OCFS2_INFO_FL_NON_COHERENT.\n\nBUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline]\nBUG: KASAN: use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]\nBUG: KASAN: use-after-free in test_bit_le include/asm-generic/bitops/le.h:21 [inline]\nBUG: KASAN: use-after-free in ocfs2_info_freefrag_scan_chain fs/ocfs2/ioctl.c:495 [inline]\nBUG: KASAN: use-after-free in ocfs2_info_freefrag_scan_bitmap fs/ocfs2/ioctl.c:588 [inline]\nBUG: KASAN: use-after-free in ocfs2_info_handle_freefrag fs/ocfs2/ioctl.c:662 [inline]\nBUG: KASAN: use-after-free in ocfs2_info_handle_request+0x1c66/0x3370 fs/ocfs2/ioctl.c:754\nRead of size 8 at addr ffff888031bce000 by task syz.0.636/1435\nCall Trace:\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120\n print_address_description mm/kasan/report.c:378 [inline]\n print_report+0xd1/0x650 mm/kasan/report.c:482\n kasan_report+0xfb/0x140 mm/kasan/report.c:595\n check_region_inline mm/kasan/generic.c:186 [inline]\n kasan_check_range+0x11c/0x200 mm/kasan/generic.c:200\n __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31\n instrument_atomic_read include/linux/instrumented.h:68 [inline]\n _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]\n test_bit_le include/asm-generic/bitops/le.h:21 [inline]\n ocfs2_info_freefrag_scan_chain fs/ocfs2/ioctl.c:495 [inline]\n ocfs2_info_freefrag_scan_bitmap fs/ocfs2/ioctl.c:588 [inline]\n ocfs2_info_handle_freefrag fs/ocfs2/ioctl.c:662 [inline]\n ocfs2_info_handle_request+0x1c66/0x3370 fs/ocfs2/ioctl.c:754\n ocfs2_info_handle+0x18d/0x2a0 fs/ocfs2/ioctl.c:828\n ocfs2_ioctl+0x632/0x6e0 fs/ocfs2/ioctl.c:913\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:597 [inline]\n __se_sys_ioctl fs/ioctl.c:583 [inline]\n __x64_sys_ioctl+0x197/0x1e0 fs/ioctl.c:583\n ...\n\n[CAUSE]\nocfs2_info_freefrag_scan_chain() uses on-disk bg_bits directly as the\nbitmap scan limit. The coherent path reads group descriptors through\nocfs2_read_group_descriptor(), which validates the descriptor before\nuse. The non-coherent path uses ocfs2_read_blocks_sync() instead and\nskips that validation, so an impossible bg_bits value can drive the\nbitmap walk past the end of the block.\n\n[FIX]\nCompute the bitmap capacity from the filesystem format with\nocfs2_group_bitmap_size(), report descriptors whose bg_bits exceeds\nthat limit, and clamp the scan to the computed capacity. This keeps the\nfreefrag report going while avoiding reads beyond the buffer.","published_at":"2026-06-24T16:29:46.737000Z","last_modified_at":null,"cvss_v3_score":7.1,"cvss_v3_vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","cvss_v3_severity":"HIGH","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":null,"nvd_references":["https://git.kernel.org/stable/c/bb2906a1065ec28de021bac2ed03f2624edd7d07","https://git.kernel.org/stable/c/3e167e230d19cd273108bab2e4c61800fc335ae8","https://git.kernel.org/stable/c/0998674eec138c55e9e349b9cbd9dbc5129a9cc8","https://git.kernel.org/stable/c/bb3c54d1e71578521111f1a1ee7d5f4761a242b8","https://git.kernel.org/stable/c/05d0cbea41167b6b061c6ba5b70ee5a9a7a24c9e","https://git.kernel.org/stable/c/4c2d62ddde8928db12f4608950b67a20e67deab2","https://git.kernel.org/stable/c/e0dcf12665d6dde37facf790803cdad44d5c328c","https://git.kernel.org/stable/c/8f687eeed3da3012152b0f9473f578869de0cd7b"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-28T17:55:28.590503Z","updated_at":"2026-06-28T23:30:49.890169Z"},"effective_severity":"HIGH","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"L","value_label":"Local"},{"metric":"AC","name":"Attack Complexity","value":"L","value_label":"Low"},{"metric":"PR","name":"Privileges Required","value":"L","value_label":"Low"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"H","value_label":"High"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"d24a10b9f8ed548981696cd36e2b4f16e6f360b1","version_start_inclusive":true,"version_end":"bb2906a1065ec28de021bac2ed03f2624edd7d07","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:d24a10b9f8ed548981696cd36e2b4f16e6f360b1:bb2906a1065ec28de021bac2ed03f2624edd7d07"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"d24a10b9f8ed548981696cd36e2b4f16e6f360b1","version_start_inclusive":true,"version_end":"3e167e230d19cd273108bab2e4c61800fc335ae8","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:d24a10b9f8ed548981696cd36e2b4f16e6f360b1:3e167e230d19cd273108bab2e4c61800fc335ae8"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"d24a10b9f8ed548981696cd36e2b4f16e6f360b1","version_start_inclusive":true,"version_end":"0998674eec138c55e9e349b9cbd9dbc5129a9cc8","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:d24a10b9f8ed548981696cd36e2b4f16e6f360b1:0998674eec138c55e9e349b9cbd9dbc5129a9cc8"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"d24a10b9f8ed548981696cd36e2b4f16e6f360b1","version_start_inclusive":true,"version_end":"bb3c54d1e71578521111f1a1ee7d5f4761a242b8","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:d24a10b9f8ed548981696cd36e2b4f16e6f360b1:bb3c54d1e71578521111f1a1ee7d5f4761a242b8"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"d24a10b9f8ed548981696cd36e2b4f16e6f360b1","version_start_inclusive":true,"version_end":"05d0cbea41167b6b061c6ba5b70ee5a9a7a24c9e","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:d24a10b9f8ed548981696cd36e2b4f16e6f360b1:05d0cbea41167b6b061c6ba5b70ee5a9a7a24c9e"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"d24a10b9f8ed548981696cd36e2b4f16e6f360b1","version_start_inclusive":true,"version_end":"4c2d62ddde8928db12f4608950b67a20e67deab2","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:d24a10b9f8ed548981696cd36e2b4f16e6f360b1:4c2d62ddde8928db12f4608950b67a20e67deab2"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"d24a10b9f8ed548981696cd36e2b4f16e6f360b1","version_start_inclusive":true,"version_end":"e0dcf12665d6dde37facf790803cdad44d5c328c","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:d24a10b9f8ed548981696cd36e2b4f16e6f360b1:e0dcf12665d6dde37facf790803cdad44d5c328c"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"d24a10b9f8ed548981696cd36e2b4f16e6f360b1","version_start_inclusive":true,"version_end":"8f687eeed3da3012152b0f9473f578869de0cd7b","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:d24a10b9f8ed548981696cd36e2b4f16e6f360b1:8f687eeed3da3012152b0f9473f578869de0cd7b"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"3.0","version_start_inclusive":true,"version_end":"3.0","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:3.0:3.0"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"0","version_start_inclusive":true,"version_end":"3.0","version_end_inclusive":false,"cpe23_uri":"cve5:linux:linux:0:3.0"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"5.10.258","version_start_inclusive":true,"version_end":"5.10.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:5.10.258:5.10.*"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"5.15.209","version_start_inclusive":true,"version_end":"5.15.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:5.15.209:5.15.*"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"6.1.175","version_start_inclusive":true,"version_end":"6.1.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:6.1.175:6.1.*"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"6.6.141","version_start_inclusive":true,"version_end":"6.6.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:6.6.141:6.6.*"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"6.12.91","version_start_inclusive":true,"version_end":"6.12.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:6.12.91:6.12.*"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"6.18.33","version_start_inclusive":true,"version_end":"6.18.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:6.18.33:6.18.*"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"7.0.10","version_start_inclusive":true,"version_end":"7.0.*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:7.0.10:7.0.*"},{"vendor_slug":"linux","vendor_name":"Linux","product_slug":"linux","product_name":"Linux","version_start":"7.1","version_start_inclusive":true,"version_end":"*","version_end_inclusive":true,"cpe23_uri":"cve5:linux:linux:7.1:*"}],"exploit_refs":[],"news":[],"references":[{"url":"https://git.kernel.org/stable/c/bb2906a1065ec28de021bac2ed03f2624edd7d07","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/3e167e230d19cd273108bab2e4c61800fc335ae8","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/0998674eec138c55e9e349b9cbd9dbc5129a9cc8","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/bb3c54d1e71578521111f1a1ee7d5f4761a242b8","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/05d0cbea41167b6b061c6ba5b70ee5a9a7a24c9e","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/4c2d62ddde8928db12f4608950b67a20e67deab2","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/e0dcf12665d6dde37facf790803cdad44d5c328c","source_type":"MISC","tags":[]},{"url":"https://git.kernel.org/stable/c/8f687eeed3da3012152b0f9473f578869de0cd7b","source_type":"MISC","tags":[]}],"timeline":[{"type":"published","at":"2026-06-24T16:29:46.737000Z","label":"CVE published","source":null}]}