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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.24%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.24% probability · 15th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-416
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/676171f9405dcaa45a33d18241c32f387dbaae39Patch
- https://git.kernel.org/stable/c/7f4a8592ff29f19c5a2ca549d0973821319afaadPatch
- https://git.kernel.org/stable/c/b64415c6b3476cf9fa4d0aea3807065b8403a937Patch
- https://git.kernel.org/stable/c/d3cca8067d43dfee4a3535c645b55f618708dccbPatch
- https://git.kernel.org/stable/c/676171f9405dcaa45a33d18241c32f387dbaae39Patch
- https://git.kernel.org/stable/c/7f4a8592ff29f19c5a2ca549d0973821319afaadPatch
- https://git.kernel.org/stable/c/b64415c6b3476cf9fa4d0aea3807065b8403a937Patch
- https://git.kernel.org/stable/c/d3cca8067d43dfee4a3535c645b55f618708dccbPatch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.