Linux Kernel up to 5.12.2 virtiofs virtio_fs_probe memory leak

Summaryinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 5.4.117/5.10.35/5.11.19/5.12/5.12.2. This vulnerability affects the function virtio_fs_probe of the component virtiofs. The manipulation leads to memory leak. This vulnerability is traded as CVE-2021-46956. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 5.4.117/5.10.35/5.11.19/5.12/5.12.2 (Operating System) and classified as problematic. This issue affects the function virtio_fs_probe of the component virtiofs. The manipulation with an unknown input leads to a memory leak vulnerability. Using CWE to declare the problem leads to CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: virtiofs: fix memory leak in virtio_fs_probe() When accidentally passing twice the same tag to qemu, kmemleak ended up reporting a memory leak in virtiofs. Also, looking at the log I saw the following error (that's when I realised the duplicated tag): virtiofs: probe of virtio5 failed with error -17 Here's the kmemleak log for reference: unreferenced object 0xffff888103d47800 (size 1024): comm "systemd-udevd", pid 118, jiffies 4294893780 (age 18.340s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff 80 90 02 a0 ff ff ff ff ................ backtrace: [] virtio_fs_probe+0x171/0x7ae [virtiofs] [] virtio_dev_probe+0x15f/0x210 [] really_probe+0xea/0x430 [] device_driver_attach+0xa8/0xb0 [] __driver_attach+0x98/0x140 [] bus_for_each_dev+0x7b/0xc0 [] bus_add_driver+0x11b/0x1f0 [] driver_register+0x8f/0xe0 [] 0xffffffffa002c013 [] do_one_initcall+0x64/0x2e0 [] do_init_module+0x5c/0x260 [] __do_sys_finit_module+0xb5/0x120 [] do_syscall_64+0x33/0x40 [] entry_SYSCALL_64_after_hwframe+0x44/0xae

The weakness was shared 02/27/2024. It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2021-46956. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 247787 (Linux Distros Unpatched Vulnerability : CVE-2021-46956), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.4.118, 5.10.36, 5.11.20, 5.12.3 or 5.13 eliminates this vulnerability. Applying the patch 310efc95c72c/d19555ff225d/9b9d60c0eb8a/5116e79fc6e6/c79c5e017892 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the vulnerability database at Tenable (247787). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 5.0
• 5.1
• 5.2
• 5.3
• 5.4
• 5.4.117
• 5.5
• 5.6
• 5.7
• 5.8
• 5.9
• 5.10
• 5.10.0
• 5.10.1
• 5.10.2
• 5.10.3
• 5.10.4
• 5.10.5
• 5.10.6
• 5.10.7
• 5.10.8
• 5.10.9
• 5.10.10
• 5.10.11
• 5.10.12
• 5.10.13
• 5.10.14
• 5.10.15
• 5.10.16
• 5.10.17
• 5.10.18
• 5.10.19
• 5.10.20
• 5.10.21
• 5.10.22
• 5.10.23
• 5.10.24
• 5.10.25
• 5.10.26
• 5.10.27
• 5.10.28
• 5.10.29
• 5.10.30
• 5.10.31
• 5.10.32
• 5.10.33
• 5.10.34
• 5.10.35
• 5.11
• 5.11.0
• 5.11.1
• 5.11.2
• 5.11.3
• 5.11.4
• 5.11.5
• 5.11.6
• 5.11.7
• 5.11.8
• 5.11.9
• 5.11.10
• 5.11.11
• 5.11.12
• 5.11.13
• 5.11.14
• 5.11.15
• 5.11.16
• 5.11.17
• 5.11.18
• 5.11.19
• 5.12
• 5.12.0
• 5.12.1
• 5.12.2

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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CVSSv4info

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CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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