4.7

CVE-2021-47599: btrfs: use latest_dev in btrfs_show_devname

Modified
AliasesUBUNTU-CVE-2021-47599DEBIAN-CVE-2021-47599
Published 19-06-2024Last modified 23-05-2026

Vulnerability summary

CVE-2021-47599 is a medium (CVSS 4.7) vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 3.9% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 4.7, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
4.7/10
010
Medium · v3.1 (NVD)
EPSS score
0.15%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 27 · Related 27
SUSE-SU-2024:2892-1SUSE-SU-2024:2894-1SUSE-SU-2024:2901-1SUSE-SU-2024:2939-1SUSE-SU-2024:2940-1SUSE-SU-2024:2947-1

Timeline

  1. 19-06-2024
    PublishedVulnerability first disclosed.
  2. 23-05-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: use latest_dev in btrfs_show_devname The test case btrfs/238 reports the warning below: WARNING: CPU: 3 PID: 481 at fs/btrfs/super.c:2509 btrfs_show_devname+0x104/0x1e8 [btrfs] CPU: 2 PID: 1 Comm: systemd Tainted: G W O 5.14.0-rc1-custom #72 Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 Call trace: btrfs_show_devname+0x108/0x1b4 [btrfs] show_mountinfo+0x234/0x2c4 m_show+0x28/0x34 seq_read_iter+0x12c/0x3c4 vfs_read+0x29c/0x2c8 ksys_read+0x80/0xec __arm64_sys_read+0x28/0x34 invoke_syscall+0x50/0xf8 do_el0_svc+0x88/0x138 el0_svc+0x2c/0x8c el0t_64_sync_handler+0x84/0xe4 el0t_64_sync+0x198/0x19c Reason: While btrfs_prepare_sprout() moves the fs_devices::devices into fs_devices::seed_list, the btrfs_show_devname() searches for the devices and found none, leading to the warning as in above. Fix: latest_dev is updated according to the changes to the device list. That means we could use the latest_dev->name to show the device name in /proc/self/mounts, the pointer will be always valid as it's assigned before the device is deleted from the list in remove or replace. The RCU protection is sufficient as the device structure is freed after synchronization.

CVSS metrics

3 scores · 3 sources · 1 version

EPSS trend

Probability

0.15%

Chance of exploitation in the next 30 days

Percentile

4%

Versus all other CVEs

30-day change

No change 0.00 pp

From 0.15% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu101 products
  • linuxAll versions (No fix recorded) | < 4.4.0-278.312 | < 4.15.0-247.259 | < 5.4.0-227.247
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 4.4.0-1152.158 | < 4.4.0-1190.205 | < 4.15.0-1189.202 | < 5.4.0-1156.166
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Linux2 products
  • linux≥ 4faf55b03823e96c44dc4e364520000ed3b12fdb, < e342c2558016ead462f376b6c6c2ac5efc17f3b1 | ≥ 4faf55b03823e96c44dc4e364520000ed3b12fdb, < 6605fd2f394bba0a0059df2b6cfc87b0b6d393a2 | fa511954694cbea4d0cb59c81c8670276920c08c | 3d3452920cacc3a46444ecca26af5d181410ff19 | ca21728e18d34fd5f449bb0581160e0eaee498a6 | 1c986b7e8c1bf8fabbc294036b003286cc3a8c7e | ≥ 4.19.141, < 4.20 | ≥ 5.4.60, < 5.5 | ≥ 5.7.17, < 5.8 | ≥ 5.8.3, < 5.9 | 5.9
  • linux_kernel< 5.15.11
Debian1 product
  • linux< 5.15.15-1

3 vendors · 104 products

References

27 links
Show all 27 references