# CVE-2022-48664: linux: In the Linux kernel, the following vulnerability has been resolved:  btrfs: fix hang during unmount when stopping a s...

CVE-2022-48664 is fixed in linux on 1 platform, first by DEBIAN-CVE-2022-48664, released April 28, 2024. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2022-48664
- Priority: Routine
- CVSS: 5.5 (medium)
- EPSS: 0.0024
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Apr 28, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  btrfs: fix hang during unmount when stopping a space reclaim worker  Often when running generic/562 from fstests we can hang during unmount, resulting in a trace like this:    Sep 07 11:52:00 debian9 unknown: run fstests generic/562 at 2022-09-07 11:52:00   Sep 07 11:55:32 debian9 kernel: INFO: task umount:49438 blocked for more than 120 seconds.   Sep 07 11:55:32 debian9 kernel:       Not tainted 6.0.0-rc2-btrfs-next-122 #1   Sep 07 11:55:32 debian9 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.   Sep 07 11:55:32 debian9 kernel: task:umount          state:D stack:    0 pid:49438 ppid: 25683 flags:0x00004000   Sep 07 11:55:32 debian9 kernel: Call Trace:   Sep 07 11:55:32 debian9 kernel:  <TASK>   Sep 07 11:55:32 debian9 kernel:  __schedule+0x3c8/0xec0   Sep 07 11:55:32 debian9 kernel:  ? rcu_read_lock_sched_held+0x12/0x70   Sep 07 11:55:32 debian9 kernel:  schedule+0x5d/0xf0   Sep 07 11:55:32 debian9 kernel:  schedule_timeout+0xf1/0x130   Sep 07 11:55:32 debian9 kernel:  ? lock_release+0x224/0x4a0   Sep 07 11:55:32 debian9 kernel:  ? lock_acquired+0x1a0/0x420   Sep 07 11:55:32 debian9 kernel:  ? trace_hardirqs_on+0x2c/0xd0   Sep 07 11:55:32 debian9 kernel:  __wait_for_common+0xac/0x200   Sep 07 11:55:32 debian9 kernel:  ? usleep_range_state+0xb0/0xb0   Sep 07 11:55:32 debian9 kernel:  __flush_work+0x26d/0x530   Sep 07 11:55:32 debian9 kernel:  ? flush_workqueue_prep_pwqs+0x140/0x140   Sep 07 11:55:32 debian9 kernel:  ? trace_clock_local+0xc/0x30   Sep 07 11:55:32 debian9 kernel:  __cancel_work_timer+0x11f/0x1b0   Sep 07 11:55:32 debian9 kernel:  ? close_ctree+0x12b/0x5b3 [btrfs]   Sep 07 11:55:32 debian9 kernel:  ? __trace_bputs+0x10b/0x170   Sep 07 11:55:32 debian9 kernel:  close_ctree+0x152/0x5b3 [btrfs]   Sep 07 11:55:32 debian9 kernel:  ? evict_inodes+0x166/0x1c0   Sep 07 11:55:32 debian9 kernel:  generic_shutdown_super+0x71/0x120   Sep 07 11:55:32 debian9 kernel:  kill_anon_super+0x14/0x30   Sep 07 11:55:32 debian9 kernel:  btrfs_kill_super+0x12/0x20 [btrfs]   Sep 07 11:55:32 debian9 kernel:  deactivate_locked_super+0x2e/0xa0   Sep 07 11:55:32 debian9 kernel:  cleanup_mnt+0x100/0x160   Sep 07 11:55:32 debian9 kernel:  task_work_run+0x59/0xa0   Sep 07 11:55:32 debian9 kernel:  exit_to_user_mode_prepare+0x1a6/0x1b0   Sep 07 11:55:32 debian9 kernel:  syscall_exit_to_user_mode+0x16/0x40   Sep 07 11:55:32 debian9 kernel:  do_syscall_64+0x48/0x90   Sep 07 11:55:32 debian9 kernel:  entry_SYSCALL_64_after_hwframe+0x63/0xcd   Sep 07 11:55:32 debian9 kernel: RIP: 0033:0x7fcde59a57a7   Sep 07 11:55:32 debian9 kernel: RSP: 002b:00007ffe914217c8 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6   Sep 07 11:55:32 debian9 kernel: RAX: 0000000000000000 RBX: 00007fcde5ae8264 RCX: 00007fcde59a57a7   Sep 07 11:55:32 debian9 kernel: RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000055b57556cdd0   Sep 07 11:55:32 debian9 kernel: RBP: 000055b57556cba0 R08: 0000000000000000 R09: 00007ffe91420570   Sep 07 11:55:32 debian9 kernel: R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000   Sep 07 11:55:32 debian9 kernel: R13: 000055b57556cdd0 R14: 000055b57556ccb8 R15: 0000000000000000   Sep 07 11:55:32 debian9 kernel:  </TASK>  What happens is the following:  1) The cleaner kthread tries to start a transaction to delete an unused    block group, but the metadata reservation can not be satisfied right    away, so a reservation ticket is created and it starts the async    metadata reclaim task (fs_info->async_reclaim_work);  2) Writeback for all the filler inodes with an i_size of 2K starts    (generic/562 creates a lot of 2K files with the goal of filling    metadata space). We try to create an inline extent for them, but we    fail when trying to insert the inline extent with -ENOSPC (at    cow_file_range_inline()) - since this is not critical, we fallback    to non-inline mode (back to cow_file_range()), reserve extents ---truncated---

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.0.2-1 | [DEBIAN-CVE-2022-48664](https://patchblox.com/security/data/fix/linux/debian-cve-2022-48664.md) | Apr 28, 2024 |
| Linux | linux Debian 13.5 (trixie) | 6.0.2-1 | [DEBIAN-CVE-2022-48664](https://patchblox.com/security/data/fix/linux/debian-cve-2022-48664.md) | Apr 28, 2024 |
| Linux | linux Debian 14 | 6.0.2-1 | [DEBIAN-CVE-2022-48664](https://patchblox.com/security/data/fix/linux/debian-cve-2022-48664.md) | Apr 28, 2024 |

---

Data as of 2026-11-08T00:53:09Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.