--- id: CVE-2026-89496 title: 'ocfs2: always run deallocs on copy-on-write completion' summary: |- 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… severity: medium cvss: 5.5 cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H' cvssSource: vendor cwe: - CWE-772 vendor: Linux product: Linux affected: - >- Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 5ff30f07def6d0e6edacf47952807b5ff60f3af6 - >- Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 2753e12853ed2023555cec2c5fe22fbaabb2c0b7 - >- Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < f0261b3aca027f5c409a402ea22f6982750f911c - >- Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < a4adaa722977f46511d4247172cd4ec991b80ff2 - >- Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 123c050eb96aae0bab74c9f06c6ad3de7992722b - >- Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 71f07b7f90b3109c9098d1b9c8efbbeece5deb8a - >- Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 09e93a60e18e83a630ff84ae00cb564bab96ab1f - >- Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 82ea9d4fc05fb7a387db547c6a7c0aa6a3719616 - Linux 2.6.32 published: '2026-09-11' updated: '2026-10-19' sourceUpdated: '2026-10-19T08:47:47.928Z' source: CVEORG sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-89496' references: - url: 'https://git.kernel.org/stable/c/5ff30f07def6d0e6edacf47952807b5ff60f3af6' - url: 'https://git.kernel.org/stable/c/2753e12853ed2023555cec2c5fe22fbaabb2c0b7' - url: 'https://git.kernel.org/stable/c/f0261b3aca027f5c409a402ea22f6982750f911c' - url: 'https://git.kernel.org/stable/c/a4adaa722977f46511d4247172cd4ec991b80ff2' - url: 'https://git.kernel.org/stable/c/123c050eb96aae0bab74c9f06c6ad3de7992722b' - url: 'https://git.kernel.org/stable/c/71f07b7f90b3109c9098d1b9c8efbbeece5deb8a' - url: 'https://git.kernel.org/stable/c/09e93a60e18e83a630ff84ae00cb564bab96ab1f' - url: 'https://git.kernel.org/stable/c/82ea9d4fc05fb7a387db547c6a7c0aa6a3719616' - url: >- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89496.json - url: 'https://access.redhat.com/security/cve/CVE-2026-89496' - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2532512' - url: 'https://www.cve.org/CVERecord?id=CVE-2026-89496' - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-89496' - url: >- https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-89496.mbox tags: - cve.org - csaf - vex - red-hat epss: 0.00177 epssPercentile: 0.07177 ingestedAt: '2026-09-14T15:23:07.452Z' --- ## Overview 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--- ## Affected - `Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 5ff30f07def6d0e6edacf47952807b5ff60f3af6` - `Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 2753e12853ed2023555cec2c5fe22fbaabb2c0b7` - `Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < f0261b3aca027f5c409a402ea22f6982750f911c` - `Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < a4adaa722977f46511d4247172cd4ec991b80ff2` - `Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 123c050eb96aae0bab74c9f06c6ad3de7992722b` - `Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 71f07b7f90b3109c9098d1b9c8efbbeece5deb8a` - `Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 09e93a60e18e83a630ff84ae00cb564bab96ab1f` - `Linux >= 6f70fa519976a379d72781d927cf8e5f5b05ec86 < 82ea9d4fc05fb7a387db547c6a7c0aa6a3719616` - `Linux 2.6.32` ## Remediation Refer to the linked advisories for vendor-supplied fixes and affected version ranges. ## Vendor advisories - **Red Hat VEX** · Moderate · updated 2026-09-15 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-89496.json)