{ "affected": [ { "ranges": [ { "events": [ { "introduced": "d24a10b9f8ed548981696cd36e2b4f16e6f360b1" }, { "fixed": "bb2906a1065ec28de021bac2ed03f2624edd7d07" }, { "fixed": "3e167e230d19cd273108bab2e4c61800fc335ae8" }, { "fixed": "0998674eec138c55e9e349b9cbd9dbc5129a9cc8" }, { "fixed": "bb3c54d1e71578521111f1a1ee7d5f4761a242b8" }, { "fixed": "05d0cbea41167b6b061c6ba5b70ee5a9a7a24c9e" }, { "fixed": "4c2d62ddde8928db12f4608950b67a20e67deab2" }, { "fixed": "e0dcf12665d6dde37facf790803cdad44d5c328c" }, { "fixed": "8f687eeed3da3012152b0f9473f578869de0cd7b" } ], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "type": "GIT" } ] }, { "package": { "ecosystem": "Linux", "name": "Kernel" }, "ranges": [ { "events": [ { "introduced": "3.0.0" }, { "fixed": "5.10.258" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.11.0" }, { "fixed": "5.15.209" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "5.16.0" }, { "fixed": "6.1.175" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.2.0" }, { "fixed": "6.6.141" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.7.0" }, { "fixed": "6.12.91" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.13.0" }, { "fixed": "6.18.33" } ], "type": "ECOSYSTEM" }, { "events": [ { "introduced": "6.19.0" }, { "fixed": "7.0.10" } ], "type": "ECOSYSTEM" } ] } ], "database_specific": { "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53040.json" }, "details": "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.", "id": "CVE-2026-53040", "modified": "2026-07-15T01:48:53.889121144Z", "published": "2026-06-24T16:29:46.737Z", "references": [ { "type": "WEB", "url": "https://git.kernel.org/stable/c/05d0cbea41167b6b061c6ba5b70ee5a9a7a24c9e" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/0998674eec138c55e9e349b9cbd9dbc5129a9cc8" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/3e167e230d19cd273108bab2e4c61800fc335ae8" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/4c2d62ddde8928db12f4608950b67a20e67deab2" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/8f687eeed3da3012152b0f9473f578869de0cd7b" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/bb2906a1065ec28de021bac2ed03f2624edd7d07" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/bb3c54d1e71578521111f1a1ee7d5f4761a242b8" }, { "type": "WEB", "url": "https://git.kernel.org/stable/c/e0dcf12665d6dde37facf790803cdad44d5c328c" }, { "type": "ADVISORY", "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53040.json" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-53040" }, { "type": "PACKAGE", "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git" } ], "schema_version": "1.8.0", "severity": [ { "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H", "type": "CVSS_V3" } ], "summary": "ocfs2: validate bg_bits during freefrag scan" }