Answer in brief
CVE-2026-53040 records a High severity (CVSS 7.1) vulnerability in ocfs2: validate bg_bits during freefrag scan. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 7.1. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=d24a10b9f8ed548981696cd36e2b4f16e6f360b1 <bb2906a1065ec28de021bac2ed03f2624edd7d07 || >=d24a10b9f8ed548981696cd36e2b4f16e6f360b1 <3e167e230d19cd273108bab2e4c61800fc335ae8 || >=d24a10b9f8ed548981696cd36e2b4f16e6f360b1 <0998674eec138c55e9e349b9cbd9dbc5129a9cc8 || >=d24a10b9f8ed548981696cd36e2b4f16e6f360b1 <bb3c54d1e71578521111f1a1ee7d5f4761a242b8 || >=d24a10b9f8ed548981696cd36e2b4f16e6f360b1 <05d0cbea41167b6b061c6ba5b70ee5a9a7a24c9e || >=d24a10b9f8ed548981696cd36e2b4f16e6f360b1 <4c2d62ddde8928db12f4608950b67a20e67deab2 || >=d24a10b9f8ed548981696cd36e2b4f16e6f360b1 <e0dcf12665d6dde37facf790803cdad44d5c328c || >=d24a10b9f8ed548981696cd36e2b4f16e6f360b1 <8f687eeed3da3012152b0f9473f578869de0cd7b | bb2906a1065ec28de021bac2ed03f2624edd7d07, 3e167e230d19cd273108bab2e4c61800fc335ae8, 0998674eec138c55e9e349b9cbd9dbc5129a9cc8, bb3c54d1e71578521111f1a1ee7d5f4761a242b8, 05d0cbea41167b6b061c6ba5b70ee5a9a7a24c9e, 4c2d62ddde8928db12f4608950b67a20e67deab2, e0dcf12665d6dde37facf790803cdad44d5c328c, 8f687eeed3da3012152b0f9473f578869de0cd7b |
| Linux/Linuxgeneric | 3.0 | Not reported |
Published upstream
Jun 24, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 24, 2026
In the Linux kernel, the following vulnerability has been resolved: ocfs2: validate bg_bits during freefrag scan [BUG] A crafted filesystem can trigger an out-of-bounds bitmap walk when OCFS2_IOC_INFO is issued with OCFS2_INFO_FL_NON_COHERENT. BUG: KASAN: use-after-free in instrument_atomic_read include/linux/instrumented.h:68 [inline] BUG: KASAN: use-after-free in _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] BUG: KASAN: use-after-free in test_bit_le include/asm-generic/bitops/le.h:21 [inline] BUG: KASAN: use-after-free in ocfs2_info_freefrag_scan_chain fs/ocfs2/ioctl.c:495 [inline] BUG: KASAN: use-after-free in ocfs2_info_freefrag_scan_bitmap fs/ocfs2/ioctl.c:588 [inline] BUG: KASAN: use-after-free in ocfs2_info_handle_freefrag fs/ocfs2/ioctl.c:662 [inline] BUG: KASAN: use-after-free in ocfs2_info_handle_request+0x1c66/0x3370 fs/ocfs2/ioctl.c:754 Read of size 8 at addr ffff888031bce000 by task syz.0.636/1435 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xbe/0x130 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xd1/0x650 mm/kasan/report.c:482 kasan_report+0xfb/0x140 mm/kasan/report.c:595 check_region_inline mm/kasan/generic.c:186 [inline] kasan_check_range+0x11c/0x200 mm/kasan/generic.c:200 __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] test_bit_le include/asm-generic/bitops/le.h:21 [inline] ocfs2_info_freefrag_scan_chain fs/ocfs2/ioctl.c:495 [inline] ocfs2_info_freefrag_scan_bitmap fs/ocfs2/ioctl.c:588 [inline] ocfs2_info_handle_freefrag fs/ocfs2/ioctl.c:662 [inline] ocfs2_info_handle_request+0x1c66/0x3370 fs/ocfs2/ioctl.c:754 ocfs2_info_handle+0x18d/0x2a0 fs/ocfs2/ioctl.c:828 ocfs2_ioctl+0x632/0x6e0 fs/ocfs2/ioctl.c:913 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x197/0x1e0 fs/ioctl.c:583 ... [CAUSE] ocfs2_info_freefrag_scan_chain() uses on-disk bg_bits directly as the bitmap scan limit. The coherent path reads group descriptors through ocfs2_read_group_descriptor(), which validates the descriptor before use. The non-coherent path uses ocfs2_read_blocks_sync() instead and skips that validation, so an impossible bg_bits value can drive the bitmap walk past the end of the block. [FIX] Compute the bitmap capacity from the filesystem format with ocfs2_group_bitmap_size(), report descriptors whose bg_bits exceeds that limit, and clamp the scan to the computed capacity. This keeps the freefrag report going while avoiding reads beyond the buffer.
Quoted source text, attributed separately from HOL analysis.