UBUNTU-CVE-2026-68460: Medium severity ubuntu/linux vulnerability
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix potential deadlock in f2fsbalancefs() When the f2fs filesystem space is nearly exhausted, we encounter deadlock issues as below: INFO: task A:1890 blocked for more than 120 seconds. Tainted: G O 6.12.41-g3fe07ddf05ab #1 "echo 0 > /proc/sys/kernel/hungtasktimeoutsecs" disables this message. task:A state:D stack:0 pid:1890 tgid:1626 ppid:1153 flags:0x00000204 Call trace: switchto+0xf4/0x158 schedule+0x27c/0x908 schedule+0x3c/0x118 ioschedule+0x44/0x68 foliowaitbitcommon+0x174/0x370 foliowaitbit+0x20/0x38 foliowaitwriteback+0x54/0xc8 truncateinodepartialfolio+0x70/0x1e0 truncateinodepagesrange+0x1b0/0x450 truncatepagecache+0x54/0x88 f2fsfilewriteiter+0x3e8/0xb80 doiterreadvwritev+0xf0/0x1e0 vfswritev+0x138/0x2c8 dowritev+0x88/0x130 arm64syswritev+0x28/0x40 invokesyscall+0x50/0x120 el0svccommon.constprop.0+0xc8/0xf0 doel0svc+0x24/0x38 el0svc+0x30/0xf8 el0t64synchandler+0x120/0x130 el0t64sync+0x190/0x198 INFO: task kworker/u8:11:2680853 blocked for more than 120 seconds. Tainted: G O 6.12.41-g3fe07ddf05ab #1 "echo 0 > /proc/sys/kernel/hungtasktimeoutsecs" disables this message. task:kworker/u8:11 state:D stack:0 pid:2680853 tgid:2680853 ppid:2 flags:0x00000208 Workqueue: writeback wbworkfn (flush-254:0) Call trace: switchto+0xf4/0x158 schedule+0x27c/0x908 schedule+0x3c/0x118 ioschedule+0x44/0x68 foliowaitbitcommon+0x174/0x370 filemapgetfolio+0x214/0x348 pagecachegetpage+0x20/0x70 f2fsgetreaddatapage+0x150/0x3e8 f2fsgetlockdatapage+0x2c/0x160 movedatapage+0x50/0x478 dogarbagecollect+0xd38/0x1528 f2fsgc+0x240/0x7e0 f2fsbalancefs+0x1a0/0x208 f2fswritesingledatapage+0x6e4/0x730 f2fswritecachepages+0x378/0x9b0 f2fswritedatapages+0x2e4/0x388 dowritepages+0x8c/0x2c8 writebacksingleinode+0x4c/0x498 writebacksbinodes+0x234/0x4a8 writebackinodeswb+0x58/0x118 wbwriteback+0x2f8/0x3c0 wbworkfn+0x2c4/0x508 processonework+0x180/0x408 workerthread+0x258/0x368 kthread+0x118/0x128 retfromfork+0x10/0x200 INFO: task kworker/u8:8:2641297 blocked for more than 120 seconds. Tainted: G O 6.12.41-g3fe07ddf05ab #1 "echo 0 > /proc/sys/kernel/hungtasktimeoutsecs" disables this message. task:kworker/u8:8 state:D stack:0 pid:2641297 tgid:2641297 ppid:2 flags:0x00000208 Workqueue: writeback wbworkfn (flush-254:0) Call trace: switchto+0xf4/0x158 schedule+0x27c/0x908 rtmutexschedule+0x30/0x60 rtmutexslowlocklocked.constprop.0+0x460/0x8a8 rwbasewritelock+0x24c/0x378 downwrite+0x1c/0x30 f2fsbalancefs+0x184/0x208 f2fswriteinode+0xf4/0x328 writebacksingleinode+0x370/0x498 writebacksbinodes+0x234/0x4a8 writebackinodeswb+0x58/0x118 wbwriteback+0x2f8/0x3c0 wbworkfn+0x2c4/0x508 processonework+0x180/0x408 workerthread+0x258/0x368 kthread+0x118/0x128 retfromfork+0x10/0x20 INFO: task B:1902 blocked for more than 120 seconds. Tainted: G O 6.12.41-g3fe07ddf05ab #1 "echo 0 > /proc/sys/kernel/hungtasktimeoutsecs" disables this message. task:B state:D stack:0 pid:1902 tgid:1626 ppid:1153 flags:0x0000020c Call trace: switchto+0xf4/0x158 schedule+0x27c/0x908 rtmutexschedule+0x30/0x60 rtmutexslowlocklocked.constprop.0+0x460/0x8a8 rwbasewritelock+0x24c/0x378 downwrite+0x1c/0x30 f2fsbalancefs+0x184/0x208 f2fsmapblocks+0x94c/0x1110 f2fsfilewriteiter+0x228/0xb80 doiterreadvwritev+0xf0/0x1e0 vfswritev+0x138/0x2c8 dowritev+0x88/0x130 arm64syswritev+0x28/0x40 invokesyscall+0x50/0x120 el0svccommon.constprop.0+0xc8/0xf0 doel0svc+0x24/0x38 el0svc+0x30/0xf8 el0t64synchandler+0x120/0x130 el0t64sync+0x190/0x198 INFO: task sync:2769849 blocked for more than 120 seconds. Tainted: G ---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 5.15.0-1117.124~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1123.132~20.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1122.131~20.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1118.128~20.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-198.208~20.04.1 - Upgrade
Upgrade
ubuntu/linux-ibm-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1111.115~20.04.1 - Upgrade
Upgrade
ubuntu/linux-intel-iotg-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1112.118~20.04.1 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-195.205~20.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1114.120~20.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-5.15to a version that resolves this vulnerability.Fixed in 5.15.0-1111.115~20.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 5.15.0-198.208 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 5.15.0-1117.124 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 5.15.0-1123.132 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 5.15.0-1122.131 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 5.15.0-1118.128 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 5.15.0-1113.119 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 5.15.0-1100.108 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 5.15.0-1111.115 - Upgrade
Upgrade
ubuntu/linux-intel-iotgto a version that resolves this vulnerability.Fixed in 5.15.0-1112.118 - Upgrade
Upgrade
ubuntu/linux-kvmto a version that resolves this vulnerability.Fixed in 5.15.0-1109.114 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 5.15.0-195.205 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 5.15.0-1112.113 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 5.15.0-1114.120 - Upgrade
Upgrade
ubuntu/linux-xilinx-zynqmpto a version that resolves this vulnerability.Fixed in 5.15.0-1080.84 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 5.15.0-1101.103 - Upgrade
Upgrade
ubuntu/linux-intel-iot-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1109.111 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 5.15.0-1116.125 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1117.124+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1123.132+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-198.208+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 5.15.0-1118.128+fips1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-147.147 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1067.70 - Upgrade
Upgrade
ubuntu/linux-aws-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1012.12~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79 - Upgrade
Upgrade
ubuntu/linux-azure-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1014.14~24.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 6.8.0-1069.76 - Upgrade
Upgrade
ubuntu/linux-azure-fde-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13~24.04.1 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79 - Upgrade
Upgrade
ubuntu/linux-gcp-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1011.11~24.04.1 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1066.74 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1052.56 - Upgrade
Upgrade
ubuntu/linux-hwe-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-31.31~24.04.1 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1067.68 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-147.147.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1018.18~24.04.1 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1064.67 - Upgrade
Upgrade
ubuntu/linux-oracle-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1011.11~24.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-31.31.1~24.04.1 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1033.38 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1062.63 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1067.70+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-147.147+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1071.79+fips1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 7.0.0-31.31 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 7.0.0-1012.12 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 7.0.0-1014.14 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 7.0.0-1011.11 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 7.0.0-1006.7 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 7.0.0-1018.18 - Upgrade
Upgrade
ubuntu/linux-nvidia-bosto a version that resolves this vulnerability.Fixed in 7.0.0-2018.18 - Upgrade
Upgrade
ubuntu/linux-oem-7.0to a version that resolves this vulnerability.Fixed in 7.0.0-1013.13 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 7.0.0-1011.11 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 7.0.0-1019.19 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 7.0.0-31.31.1 - Upgrade
Upgrade
ubuntu/linux-riscvto a version that resolves this vulnerability.Fixed in 7.0.0-31.31.1
Event History
Frequently Asked Questions
Which systems are exposed to this issue?
Systems using an affected Ubuntu kernel package and the f2fs filesystem are relevant. The listed packages include linux, linux-fips, linux-aws, linux-azure, linux-aws-fips, linux-azure-fips, linux-gcp, and linux-gcp-fips.
What conditions trigger the deadlock?
The issue occurs when space on an f2fs filesystem is nearly exhausted. Under that condition, filesystem activity can block tasks for more than 120 seconds while waiting on writeback-related operations.
How can I recognize that a system may already be affected?
Look for hung-task reports showing tasks blocked for more than 120 seconds, particularly call traces involving f2fs_file_write_iter(), f2fs_balance_fs(), truncate_pagecache(), or folio_wait_writeback(). The provided example also shows blocked f2fs worker threads such as kworker/u8.