UBUNTU-CVE-2025-22127: Medium severity ubuntu/linux-hwe-edge vulnerability
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix potential deadloop in preparecompressoverwrite() Jan Prusakowski reported a kernel hang issue as below: When running xfstests on linux-next kernel (6.14.0-rc3, 6.12) I encountered a problem in generic/475 test where fsstress process gets blocked in f2fswritedatapages() and the test hangs. The options I used are: MKFSOPTIONS -- -O compression -O extraattr -O projectquota -O quota /dev/vdc MOUNTOPTIONS -- -o acl,userxattr -o discard,compressextension= /dev/vdc /vdc INFO: task kworker/u8:0:11 blocked for more than 122 seconds. Not tainted 6.14.0-rc3-xfstests-lockdep #1 "echo 0 > /proc/sys/kernel/hungtasktimeoutsecs" disables this message. task:kworker/u8:0 state:D stack:0 pid:11 tgid:11 ppid:2 taskflags:0x4208160 flags:0x00004000 Workqueue: writeback wbworkfn (flush-253:0) Call Trace: <TASK> schedule+0x309/0x8e0 schedule+0x3a/0x100 schedulepreemptdisabled+0x15/0x30 mutexlock+0x59a/0xdb0 f2fswritedatapages+0x3ac/0x400 dowritepages+0xe8/0x290 writebacksingleinode+0x5c/0x360 writebacksbinodes+0x22f/0x570 wbwriteback+0xb0/0x410 wbdowriteback+0x47/0x2f0 wbworkfn+0x5a/0x1c0 processonework+0x223/0x5b0 workerthread+0x1d5/0x3c0 kthread+0xfd/0x230 retfromfork+0x31/0x50 retfromforkasm+0x1a/0x30 </TASK> The root cause is: once generic/475 starts toload error table to dm device, f2fspreparecompressoverwrite() will loop reading compressed cluster pages due to IO error, meanwhile it has held .writepages lock, it can block all other writeback tasks. Let's fix this issue w/ below changes: - add f2fshandlepageeio() in preparecompressoverwrite() to detect IO error. - detect cperror earler in f2fsreadmultipages().
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
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ubuntu/linux-aws-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1069.74~22.04.1 - Upgrade
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ubuntu/linux-azure-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1073.82~22.04.1 - Upgrade
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ubuntu/linux-azure-fde-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1071.78~22.04.1 - Upgrade
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ubuntu/linux-gcp-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1073.81~22.04.1 - Upgrade
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ubuntu/linux-ibm-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1069.70~22.04.1 - Upgrade
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ubuntu/linux-lowlatency-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-149.149.1~22.04.1 - Upgrade
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ubuntu/linux-oracle-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1067.71~22.04.1 - Upgrade
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ubuntu/linux-realtime-6.8to a version that resolves this vulnerability.Fixed in 6.8.1-1064.65~22.04.1 - Upgrade
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ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-149.149 - Upgrade
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ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1069.74 - Upgrade
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ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1073.82 - Upgrade
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ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1073.81 - Upgrade
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ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1068.77 - Upgrade
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ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1053.57 - Upgrade
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ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1069.70 - Upgrade
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ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-149.149.1 - Upgrade
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ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1067.70 - Upgrade
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ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1067.71 - Upgrade
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ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.8.0-1068.72 - Upgrade
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ubuntu/linux-vmwareto a version that resolves this vulnerability.Fixed in 6.8.0-1010.10 - Upgrade
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ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1036.41 - Upgrade
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ubuntu/linux-raspi-realtimeto a version that resolves this vulnerability.Fixed in 6.8.0-2056.58 - Upgrade
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ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1064.65 - Upgrade
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ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1069.74+fips1 - Upgrade
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ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1073.82+fips1 - Upgrade
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ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1073.81+fips1
Event History
Frequently Asked Questions
Which systems are most exposed to this issue?
Systems using an affected Ubuntu kernel package and an F2FS filesystem with compression enabled are implicated. The reported hang occurred during writeback while running filesystem stress testing.
What level of access would an attacker need?
The severity vector indicates local access and low privileges are required. No user interaction is required.
What is the practical impact?
The issue can cause a kernel writeback worker to block, leading to a filesystem operation hang and denial of service. The provided severity vector indicates availability impact only, with no confidentiality or integrity impact.
How can I identify a potentially affected configuration?
Check whether the system uses one of the listed Ubuntu kernel packages and has F2FS filesystems mounted with compression enabled. A symptom described in the report is a blocked writeback worker, including tasks stuck in __f2fs_write_data_pages().