CVE-2022-50089
CVE-2022-50089 is a medium-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 5.5. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low.
Key facts
- Severity: Medium (CVSS 3.x base score 5.5)
- EPSS exploit prediction: 0% (5th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2022-55355
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: ensure pages are unlocked on cow_file_range() failure There is a hung_task report on zoned btrfs like below. https://github.com/naota/linux/issues/59 [726.328648] INFO: task rocksdb:high0:11085 blocked for more than 241 seconds. [726.329839] Not tainted 5.16.0-rc1+ #1 [726.330484] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [726.331603] task:rocksdb:high0 state:D stack: 0 pid:11085 ppid: 11082 flags:0x00000000 [726.331608] Call Trace: [726.331611] <TASK> [726.331614] __schedule+0x2e5/0x9d0 [726.331622] schedule+0x58/0xd0 [726.331626] io_schedule+0x3f/0x70 [726.331629] __folio_lock+0x125/0x200 [726.331634] ? find_get_entries+0x1bc/0x240 [726.331638] ? filemap_invalidate_unlock_two+0x40/0x40 [726.331642] truncate_inode_pages_range+0x5b2/0x770 [726.331649] truncate_inode_pages_final+0x44/0x50 [726.331653] btrfs_evict_inode+0x67/0x480 [726.331658] evict+0xd0/0x180 [726.331661] iput+0x13f/0x200 [726.331664] do_unlinkat+0x1c0/0x2b0 [726.331668] __x64_sys_unlink+0x23/0x30 [726.331670] do_syscall_64+0x3b/0xc0 [726.331674] entry_SYSCALL_64_after_hwframe+0x44/0xae [726.331677] RIP: 0033:0x7fb9490a171b [726.331681] RSP: 002b:00007fb943ffac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 [726.331684] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb9490a171b [726.331686] RDX: 00007fb943ffb040 RSI: 000055a6bbe6ec20 RDI: 00007fb94400d300 [726.331687] RBP: 00007fb943ffad00 R08: 0000000000000000 R09: 0000000000000000 [726.331688] R10: 0000000000000031 R11: 0000000000000246 R12: 00007fb943ffb000 [726.331690] R13: 00007fb943ffb040 R14: 0000000000000000 R15: 00007fb943ffd260 [726.331693] </TASK> While we debug the issue, we found running fstests generic/551 on 5GB non-zoned null_blk device in the emulated zoned mode also had a similar hung issue. Also, we can reproduce the same symptom with an error injected cow_file_range() setup. The hang occurs when cow_file_range() fails in the middle of allocation. cow_file_range() called from do_allocation_zoned() can split the give region ([start, end]) for allocation depending on current block group usages. When btrfs can allocate bytes for one part of the split regions but fails for the other region (e.g. because of -ENOSPC), we return the error leaving the pages in the succeeded regions locked. Technically, this occurs only when @unlock == 0. Otherwise, we unlock the pages in an allocated region after creating an ordered extent. Considering the callers of cow_file_range(unlock=0) won't write out the pages, we can unlock the pages on error exit from cow_file_range(). So, we can ensure all the pages except @locked_page are unlocked on error case. In summary, cow_file_range now behaves like this: - page_started == 1 (return value) - All the pages are unlocked. IO is started. - unlock == 1 - All the pages except @locked_page are unlocked in any case - unlock == 0 - On success, all the pages are locked for writing out them - On failure, all the pages except @locked_page are unlocked
Frequently asked questions
- What is CVE-2022-50089?
- In the Linux kernel, the following vulnerability has been resolved: btrfs: ensure pages are unlocked on cow_file_range() failure There is a hung_task report on zoned btrfs like below. https://github.com/naota/linux/issues/59 [726.328648] INFO: task rocksdb:high0:11085 blocked for more than 241 seconds. [726.329839] Not tainted 5.16.0-rc1+ #1 [726.330484] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [726.331603] task:rocksdb:high0 state:D stack: 0 pid:11085 ppid: 11082 flags:0x00000000 [726.331608] Call Trace: [726.331611] <TASK> [726.331614] __schedule+0x2e5/0x9d0 [726.331622] schedule+0x58/0xd0 [726.331626] io_schedule+0x3f/0x70 [726.331629] __folio_lock+0x125/0x200 [726.331634] ? find_get_entries+0x1bc/0x240 [726.331638] ? filemap_invalidate_unlock_two+0x40/0x40 [726.331642] truncate_inode_pages_range+0x5b2/0x770 [726.331649] truncate_inode_pages_final+0x44/0x50 [726.331653] btrfs_evict_inode+0x67/0x480 [726.331658] evict+0xd0/0x180 [726.331661] iput+0x13f/0x200 [726.331664] do_unlinkat+0x1c0/0x2b0 [726.331668] __x64_sys_unlink+0x23/0x30 [726.331670] do_syscall_64+0x3b/0xc0 [726.331674] entry_SYSCALL_64_after_hwframe+0x44/0xae [726.331677] RIP: 0033:0x7fb9490a171b [726.331681] RSP: 002b:00007fb943ffac68 EFLAGS: 00000246 ORIG_RAX: 0000000000000057 [726.331684] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb9490a171b [726.331686] RDX: 00007fb943ffb040 RSI: 000055a6bbe6ec20 RDI: 00007fb94400d300 [726.331687] RBP: 00007fb943ffad00 R08: 0000000000000000 R09: 0000000000000000 [726.331688] R10: 0000000000000031 R11: 0000000000000246 R12: 00007fb943ffb000 [726.331690] R13: 00007fb943ffb040 R14: 0000000000000000 R15: 00007fb943ffd260 [726.331693] </TASK> While we debug the issue, we found running fstests generic/551 on 5GB non-zoned null_blk device in the emulated zoned mode also had a similar hung issue. Also, we can reproduce the same symptom with an error injected cow_file_range() setup. The hang occurs when cow_file_range() fails in the middle of allocation. cow_file_range() called from do_allocation_zoned() can split the give region ([start, end]) for allocation depending on current block group usages. When btrfs can allocate bytes for one part of the split regions but fails for the other region (e.g. because of -ENOSPC), we return the error leaving the pages in the succeeded regions locked. Technically, this occurs only when @unlock == 0. Otherwise, we unlock the pages in an allocated region after creating an ordered extent. Considering the callers of cow_file_range(unlock=0) won't write out the pages, we can unlock the pages on error exit from cow_file_range(). So, we can ensure all the pages except @locked_page are unlocked on error case. In summary, cow_file_range now behaves like this: - page_started == 1 (return value) - All the pages are unlocked. IO is started. - unlock == 1 - All the pages except @locked_page are unlocked in any case - unlock == 0 - On success, all the pages are locked for writing out them - On failure, all the pages except @locked_page are unlocked
- How severe is CVE-2022-50089?
- CVE-2022-50089 has a CVSS 3.x base score of 5.5, rated medium severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
- Is CVE-2022-50089 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (5th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2022-50089?
- CVE-2022-50089 affects Linux Linux Kernel. See the affected-products list for the exact vulnerable versions.
- How do I fix CVE-2022-50089?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
- Does CVE-2022-50089 have an EU (EUVD) identifier?
- Yes. CVE-2022-50089 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2022-55355.
- When was CVE-2022-50089 published?
- CVE-2022-50089 was published on 2025-06-18 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/9535ec371d741fa037e37eddc0a5b25ba82d0027
- https://git.kernel.org/stable/c/9ce7466f372d83054c7494f6b3e4b9abaf3f0355
- https://git.kernel.org/stable/c/b367f125c80fa838eae49e3b138dc67dfc9f46ef
- https://git.kernel.org/stable/c/e160aa87c87a9c4e0c8d1430235f715a3a91e2cd
Affected products (1)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
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