Strix
26.1K

CVE-2021-47081

HIGHCVSS 7.8/10EPSS 0.23%

Last modified

CVE-2021-47081 is a high-severity vulnerability rated 7.8/10 on the CVSS scale. In the Linux kernel, the following vulnerability has been resolved: habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory Our code analyzer reported a uaf. In gaudi_memset_device_memory, cb is get via hl_cb_kernel_create() with 2 refcount. If hl_cs_allocate_job() failed, the execution runs into release_cb branch. One ref of cb is dropped by hl_cb_put(cb) and could be freed if other thread also drops one ref. EPSS estimates a 0.23% chance of exploitation in the next 30 days.

Description

In the Linux kernel, the following vulnerability has been resolved: habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory Our code analyzer reported a uaf. In gaudi_memset_device_memory, cb is get via hl_cb_kernel_create() with 2 refcount. If hl_cs_allocate_job() failed, the execution runs into release_cb branch. One ref of cb is dropped by hl_cb_put(cb) and could be freed if other thread also drops one ref. Then cb is used by cb->id later, which is a potential uaf. My patch add a variable 'id' to accept the value of cb->id before the hl_cb_put(cb) is called, to avoid the potential uaf.

Metrics

CVSS 3.1
7.8/10

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Probability
0.23%

13.8th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersionsUpdate
LinuxLinux Kernel>= 5.12, < 5.12.7—
LinuxLinux Kernel5.13Rc1

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2021-47081?
In the Linux kernel, the following vulnerability has been resolved: habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory Our code analyzer reported a uaf. In gaudi_memset_device_memory, cb is get via hl_cb_kernel_create() with 2 refcount. If hl_cs_allocate_job() failed, the execution runs into release_cb branch. One ref of cb is dropped by hl_cb_put(cb) and could be freed if other thread also drops one ref. Then cb is used by cb->id later, which is a potential uaf. My patch add a variable 'id' to accept the value of cb->id before the hl_cb_put(cb) is called, to avoid the potential uaf.
How severe is CVE-2021-47081?
CVE-2021-47081 has a CVSS score of 7.8/10 (HIGH severity). The EPSS model estimates a 0.23% probability of exploitation in the next 30 days.
How do I fix CVE-2021-47081?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2021-47081?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST