Evidence-led vulnerability intelligence · 2026-09-12 01:49 IST

CVE-2026-89496

In the Linux kernel, the following vulnerability has been resolved: ocfs2: always run deallocs on copy-on-write completion Local fuzzing of 6.12.94 has found the following memory leak caused by doing 'copy_file_range()' within the same filesystem: unreferenced object 0xffff88812192c980 (size 32): comm "syz.0.49", pid 12095, jiffies 4294964143 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 08 00 00 00 00 00 00 00 ................ c0 c5 92 21 81 88 ff ff 00 02 00 00 00 06 00 00 ...!............ backtrace (crc 7068d63f): kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline] slab_post_alloc_hook mm/slub.c:4152 [inline] slab_alloc_node mm/slub.c:4197 [inline] __kmalloc_cache_noprof+0x168/0x2c0 mm/slub.c:4358 kmalloc_noprof include/linux/slab.h:878 [inline] ocfs2_find_per_slot_free_list fs/ocfs2/alloc.c:6618 [inline] ocfs2_cache_block_dealloc+0x155/0x4b0 fs/ocfs2/alloc.c:6786 ocfs2_cache_extent_block_free fs/ocfs2/alloc.c:6819 [inline] ocfs2_unlink_path+0x286/0x450 fs/ocfs2/alloc.c:2613 ocfs2_rotate_subtree_left fs/ocfs2/alloc.c:2779 [inline] __ocfs2_rotate_tree_left+0x1f6f/0x2da0 fs/ocfs2/alloc.c:2985 ocfs2_rotate_tree_left+0x283/0xe00 fs/ocfs2/alloc.c:3237 ocfs2_try_to_merge_extent+0xf56/0x1a20 fs/ocfs2/alloc.c:3825 ocfs2_split_extent+0x15f4/0x2940 fs/ocfs2/alloc.c:5138 ocfs2_clear_ext_refcount+0x2f6/0x550 fs/ocfs2/refcounttree.c:3098 ocfs2_replace_clusters fs/ocfs2/refcounttree.c:3131 [inline] ocfs2_make_clusters_writable fs/ocfs2/refcounttree.c:3255 [inline] ocfs2_replace_cow+0x991/0x1660 fs/ocfs2/refcounttree.c:3349 ocfs2_refcount_cow_hunk fs/ocfs2/refcounttree.c:3427 [inline] ocfs2_refcount_cow+0x5e1/0x9f0 fs/ocfs2/refcounttree.c:3470 ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2340 [inline] ocfs2_file_write_iter+0xbda/0x1880 fs/ocfs2/file.c:2451 iter_file_splice_write+0x890/0xf60 fs/splice.c:743 do_splice_from fs/splice.c:944 [inline] direct_splice_actor+0x232/0x480 fs/splice.c:1167 splice_direct_to_actor+0x4b4/0xb60 fs/splice.c:1111 do_splice_direct_actor fs/splice.c:1210 [inline] do_splice_direct+0x10f/0x1c0 fs/splice.c:1236 do_sendfile+0x430/0xbf0 fs/read_write.c:1388 unreferenced object 0xffff88812192c5c0 (size 32): comm "syz.0.49", pid 12095, jiffies 4294964143 hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 29 70 00 00 00 00 00 00 19 00 00 00 00 00 00 00 )p.............. backtrace (crc afec850f): kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline] slab_post_alloc_hook mm/slub.c:4152 [inline] slab_alloc_node mm/slub.c:4197 [inline] __kmalloc_cache_noprof+0x168/0x2c0 mm/slub.c:4358 kmalloc_noprof include/linux/slab.h:878 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] ocfs2_cache_block_dealloc+0x25c/0x4b0 fs/ocfs2/alloc.c:6793 ocfs2_cache_extent_block_free fs/ocfs2/alloc.c:6819 [inline] ocfs2_unlink_path+0x286/0x450 fs/ocfs2/alloc.c:2613 ocfs2_rotate_subtree_left fs/ocfs2/alloc.c:2779 [inline] __ocfs2_rotate_tree_left+0x1f6f/0x2da0 fs/ocfs2/alloc.c:2985 ocfs2_rotate_tree_left+0x283/0xe00 fs/ocfs2/alloc.c:3237 ocfs2_try_to_merge_extent+0xf56/0x1a20 fs/ocfs2/alloc.c:3825 ocfs2_split_extent+0x15f4/0x2940 fs/ocfs2/alloc.c:5138 ocfs2_clear_ext_refcount+0x2f6/0x550 fs/ocfs2/refcounttree.c:3098 ocfs2_replace_clusters fs/ocfs2/refcounttree.c:3131 [inline] ocfs2_make_clusters_writable fs/ocfs2/refcounttree.c:3255 [inline] ocfs2_replace_cow+0x991/0x1660 fs/ocfs2/refcounttree.c:3349 ocfs2_refcount_cow_hunk fs/ocfs2/refcounttree.c:3427 [inline] ocfs2_refcount_cow+0x5e1/0x9f0 fs/ocfs2/refcounttree.c:3470 ocfs2_prepare_inode_for_write fs/ocfs2/file.c:2340 [inline] ocfs2_file_write_iter+0xbda/0x1880 fs/ocfs2/file.c:2451 iter_file_splice_write+0x890/0xf60 fs/splice.c:743 do_splice_from fs/splice.c:9 ---truncated---

UNRATED · N/ALinux

Executive briefing

A structured intelligence assessment has not yet been generated. The source description is shown above. The background enrichment worker will retry this record.

Assessment: Potential exposure only — validate product, version, configuration and vendor applicability.

Evidence confidence: Not assessed Evidence-derived, not an exploitability verdict

Severity & attack characteristics

N/A / 10 · CVSS

CVSS vector:
Not supplied

No CVSS vector is currently available in the source record.

Technical explanation & impact

Technical root-cause details are not available in the current source record.

Assess the impact using the published CVSS metrics and the affected vendor component.

Affected products and versions

NVD has not supplied machine-readable vulnerable CPE product/version entries for this CVE. This is an information gap, not proof that no products are affected. Check the vendor advisory references below.

Remediation & validation

  1. Identify exposure by comparing the affected product and version ranges with your asset inventory, SBOM and externally exposed services.
  2. Review the linked vendor security advisory or patch notes. Upgrade to a vendor-confirmed fixed release; do not infer a fixed version from the CVE description.
  3. Until patched, consider restricting network access or disabling the affected feature where operationally safe. These are temporary controls, not a substitute for a vendor fix.
  4. Validate the remediation with a version check and vulnerability rescan, then retain change evidence.

No fixed version is displayed unless it is explicitly established by a vendor advisory. Follow the vendor's release notes for exact product and branch applicability.

Vendor advisories, patches & exploit references

No external references are currently supplied in the CVE record.

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