CVE-2021-47599
MediumIn 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 3.1 score
4.7
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness type
CWE-362CVE-2021-47599 is a Race Condition vulnerability
What is Race Condition?
The product contains a code sequence that can run concurrently with other code, creating unexpected states. Learn more on MITRE CWE
References
The following references provide additional information about CVE-2021-47599 including vendor advisories, patch commits, exploit details, and third-party analysis. Links are sourced from the NIST NVD database.
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PatchKernel patch commithttps://git.kernel.org/stable/c/6605fd2f394bba0a0059df2b6cfc87b0b6d393a2
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PatchKernel patch commithttps://git.kernel.org/stable/c/e342c2558016ead462f376b6c6c2ac5efc17f3b1
Frequently asked questions
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What is CVE-2021-47599?
CVE-2021-47599 is a Medium severity Linux kernel vulnerability with a CVSS score of 4.7 out of 10 , classified as a Race Condition flaw (CWE-362) . CVE-2021-47599 has not been confirmed as actively exploited and is not listed in the CISA KEV catalog.
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What is the CVSS score for CVE-2021-47599?
CVE-2021-47599 has a CVSS score of 4.7 out of 10, rated Medium severity (CVSS 3.1). The vector string is
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H. -
Is there a patch available for CVE-2021-47599?
No patch is currently available for CVE-2021-47599. Monitor the NIST NVD and your Linux distribution's security advisories for updates.
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Is CVE-2021-47599 actively exploited?
No — CVE-2021-47599 has not been confirmed as actively exploited. It is not listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.
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What is Race Condition (CWE-362)?
The product contains a code sequence that can run concurrently with other code, creating unexpected states. View CWE-362 on MITRE CWE →