Vulnerability Details : 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.
Vulnerability category: Memory Corruption
Products affected by CVE-2021-47081
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-47081
0.03%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 7 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-47081
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
7.8
|
HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
1.8
|
5.9
|
NIST | 2024-12-09 |
CWE ids for CVE-2021-47081
-
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.Assigned by: nvd@nist.gov (Primary)
References for CVE-2021-47081
-
https://git.kernel.org/stable/c/115726c5d312b462c9d9931ea42becdfa838a076
habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/b49f5af30b0e4064fbd91e83823a4bfcb2c7a3e7
habanalabs/gaudi: Fix a potential use after free in gaudi_memset_device_memory - kernel/git/stable/linux.git - Linux kernel stable treePatch
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