Vulnerability Details : CVE-2021-47026
In the Linux kernel, the following vulnerability has been resolved:
RDMA/rtrs-clt: destroy sysfs after removing session from active list
A session can be removed dynamically by sysfs interface "remove_path" that
eventually calls rtrs_clt_remove_path_from_sysfs function. The current
rtrs_clt_remove_path_from_sysfs first removes the sysfs interfaces and
frees sess->stats object. Second it removes the session from the active
list.
Therefore some functions could access non-connected session and access the
freed sess->stats object even-if they check the session status before
accessing the session.
For instance rtrs_clt_request and get_next_path_min_inflight check the
session status and try to send IO to the session. The session status
could be changed when they are trying to send IO but they could not catch
the change and update the statistics information in sess->stats object,
and generate use-after-free problem.
(see: "RDMA/rtrs-clt: Check state of the rtrs_clt_sess before reading its
stats")
This patch changes the rtrs_clt_remove_path_from_sysfs to remove the
session from the active session list and then destroy the sysfs
interfaces.
Each function still should check the session status because closing or
error recovery paths can change the status.
Vulnerability category: Memory Corruption
Products affected by CVE-2021-47026
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2021-47026
0.04%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 5 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2021-47026
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 | 2025-01-09 |
CWE ids for CVE-2021-47026
-
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.Assigned by: nvd@nist.gov (Primary)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-2021-47026
-
https://git.kernel.org/stable/c/d3cca8067d43dfee4a3535c645b55f618708dccb
RDMA/rtrs-clt: destroy sysfs after removing session from active list - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/b64415c6b3476cf9fa4d0aea3807065b8403a937
RDMA/rtrs-clt: destroy sysfs after removing session from active list - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/676171f9405dcaa45a33d18241c32f387dbaae39
RDMA/rtrs-clt: destroy sysfs after removing session from active list - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/7f4a8592ff29f19c5a2ca549d0973821319afaad
RDMA/rtrs-clt: destroy sysfs after removing session from active list - kernel/git/stable/linux.git - Linux kernel stable treePatch
Jump to