CVE-2021-47198: scsi: lpfc: Fix use-after-free in lpfc_unreg_rpi() routine

Vulnerability summary

CVE-2021-47198 is a high (CVSS 7.8) Use After Free vulnerability in linux. EPSS estimates a 0.22% chance of exploitation in the next 30 days, higher than 12.5% of scored vulnerabilities.

Timeline

1. 10-04-2024
   PublishedVulnerability first disclosed.
2. 11-05-2026
   Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Fix use-after-free in lpfc_unreg_rpi() routine An error is detected with the following report when unloading the driver: "KASAN: use-after-free in lpfc_unreg_rpi+0x1b1b" The NLP_REG_LOGIN_SEND nlp_flag is set in lpfc_reg_fab_ctrl_node(), but the flag is not cleared upon completion of the login. This allows a second call to lpfc_unreg_rpi() to proceed with nlp_rpi set to LPFC_RPI_ALLOW_ERROR. This results in a use after free access when used as an rpi_ids array index. Fix by clearing the NLP_REG_LOGIN_SEND nlp_flag in lpfc_mbx_cmpl_fc_reg_login().

• CWE-416Use After FreeThe 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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.