UBUNTU-CVE-2026-89496: Medium severity ubuntu/linux vulnerability
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 'copyfilerange()' 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): kmemleakallocrecursive include/linux/kmemleak.h:42 [inline] slabpostallochook mm/slub.c:4152 [inline] slaballocnode mm/slub.c:4197 [inline] kmalloccachenoprof+0x168/0x2c0 mm/slub.c:4358 kmallocnoprof include/linux/slab.h:878 [inline] ocfs2findperslotfreelist fs/ocfs2/alloc.c:6618 [inline] ocfs2cacheblockdealloc+0x155/0x4b0 fs/ocfs2/alloc.c:6786 ocfs2cacheextentblockfree fs/ocfs2/alloc.c:6819 [inline] ocfs2unlinkpath+0x286/0x450 fs/ocfs2/alloc.c:2613 ocfs2rotatesubtreeleft fs/ocfs2/alloc.c:2779 [inline] ocfs2rotatetreeleft+0x1f6f/0x2da0 fs/ocfs2/alloc.c:2985 ocfs2rotatetreeleft+0x283/0xe00 fs/ocfs2/alloc.c:3237 ocfs2trytomergeextent+0xf56/0x1a20 fs/ocfs2/alloc.c:3825 ocfs2splitextent+0x15f4/0x2940 fs/ocfs2/alloc.c:5138 ocfs2clearextrefcount+0x2f6/0x550 fs/ocfs2/refcounttree.c:3098 ocfs2replaceclusters fs/ocfs2/refcounttree.c:3131 [inline] ocfs2makeclusterswritable fs/ocfs2/refcounttree.c:3255 [inline] ocfs2replacecow+0x991/0x1660 fs/ocfs2/refcounttree.c:3349 ocfs2refcountcowhunk fs/ocfs2/refcounttree.c:3427 [inline] ocfs2refcountcow+0x5e1/0x9f0 fs/ocfs2/refcounttree.c:3470 ocfs2prepareinodeforwrite fs/ocfs2/file.c:2340 [inline] ocfs2filewriteiter+0xbda/0x1880 fs/ocfs2/file.c:2451 iterfilesplicewrite+0x890/0xf60 fs/splice.c:743 dosplicefrom fs/splice.c:944 [inline] directspliceactor+0x232/0x480 fs/splice.c:1167 splicedirecttoactor+0x4b4/0xb60 fs/splice.c:1111 dosplicedirectactor fs/splice.c:1210 [inline] dosplicedirect+0x10f/0x1c0 fs/splice.c:1236 dosendfile+0x430/0xbf0 fs/readwrite.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): kmemleakallocrecursive include/linux/kmemleak.h:42 [inline] slabpostallochook mm/slub.c:4152 [inline] slaballocnode mm/slub.c:4197 [inline] kmalloccachenoprof+0x168/0x2c0 mm/slub.c:4358 kmallocnoprof include/linux/slab.h:878 [inline] kzallocnoprof include/linux/slab.h:1014 [inline] ocfs2cacheblockdealloc+0x25c/0x4b0 fs/ocfs2/alloc.c:6793 ocfs2cacheextentblockfree fs/ocfs2/alloc.c:6819 [inline] ocfs2unlinkpath+0x286/0x450 fs/ocfs2/alloc.c:2613 ocfs2rotatesubtreeleft fs/ocfs2/alloc.c:2779 [inline] ocfs2rotatetreeleft+0x1f6f/0x2da0 fs/ocfs2/alloc.c:2985 ocfs2rotatetreeleft+0x283/0xe00 fs/ocfs2/alloc.c:3237 ocfs2trytomergeextent+0xf56/0x1a20 fs/ocfs2/alloc.c:3825 ocfs2splitextent+0x15f4/0x2940 fs/ocfs2/alloc.c:5138 ocfs2clearextrefcount+0x2f6/0x550 fs/ocfs2/refcounttree.c:3098 ocfs2replaceclusters fs/ocfs2/refcounttree.c:3131 [inline] ocfs2makeclusterswritable fs/ocfs2/refcounttree.c:3255 [inline] ocfs2replacecow+0x991/0x1660 fs/ocfs2/refcounttree.c:3349 ocfs2refcountcowhunk fs/ocfs2/refcounttree.c:3427 [inline] ocfs2refcountcow+0x5e1/0x9f0 fs/ocfs2/refcounttree.c:3470 ocfs2prepareinodeforwrite fs/ocfs2/file.c:2340 [inline] ocfs2filewriteiter+0xbda/0x1880 fs/ocfs2/file.c:2451 iterfilesplicewrite+0x890/0xf60 fs/splice.c:743 dosplicefrom fs/splice.c:9 ---truncated---
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1119.126~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1125.134~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1124.133~20.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1120.130~20.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-202.212~20.04.1 - Upgrade
Upgrade
ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1113.117~20.04.1 - Upgrade
Upgrade
ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1114.120~20.04.1 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-197.207~20.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegra-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1070.72~20.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1116.122~20.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1113.117~20.04.2 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-202.212 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1119.126 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1125.134 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1124.133 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1120.130 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 5.15.0-1115.121 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 5.15.0-1102.110 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.15.0-1113.117 - Upgrade
Upgrade
ubuntu/linux-intel-iotgto a version that resolves this vulnerability.Fixed in 5.15.0-1114.120 - Upgrade
Upgrade
ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1111.116 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-197.207 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1114.115 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 5.15.0-1070.72 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegra-igxto a version that resolves this vulnerability.Fixed in 5.15.0-1059.59 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1116.122 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1103.105 - Upgrade
Upgrade
ubuntu/linux-intel-iot-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1111.115 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1118.127 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1119.126+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1125.134+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-202.212+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1120.130+fips1 - Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1~24.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-42.42 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1016.17 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1016.18 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1017.17 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1015.16 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-42.42.1
Event History
Frequently Asked Questions
Which Ubuntu kernel package families are listed as affected?
The listed packages are ubuntu/linux, ubuntu/linux-fips, ubuntu/linux-aws, ubuntu/linux-azure, ubuntu/linux-aws-fips, ubuntu/linux-azure-fips, ubuntu/linux-gcp, and ubuntu/linux-gcp-fips.
What activity triggers the reported leak?
The issue was found during copy_file_range() operations where the source and destination are within the same filesystem. The affected code path is in OCFS2 copy-on-write completion and block deallocation handling.
What is the observed impact of the issue?
The reported impact is a kernel memory leak, with an unreferenced allocation originating from OCFS2 block-deallocation code. The report identifies it through local fuzzing and a kmemleak backtrace.