CVE-2024-49960

Name of the Vulnerable Software and Affected Versions Linux kernel versions prior to 6.6.58

Description The issue is related to the ext4 fill super() function in the Linux kernel's ext4 file system, which is associated with the reuse of previously freed memory. This can potentially allow an attacker to impact the confidentiality, integrity, and availability of protected information. The problem occurs when the del timer sync function cancels the s err report timer, which reminds about file system errors daily, but the timer is not guaranteed to be inactive before kfree(sbi) is called. When file system mounting fails, the flow goes to failed mount3, where an error occurs when ext4 stop mmpd is called, causing a read I/O failure and triggering the ext4 handle error function that re-arms the timer.

Recommendations To resolve the issue, update to Linux kernel version 6.6.58 or later. As a temporary workaround, consider disabling the ext4 fill super() function until a patch is available. Restrict access to the vulnerable ext4 file system module to minimize the risk of exploitation. Avoid using the s err report timer in the affected ext4 file system until the issue is resolved. Cancel the s err report timer after calling ext4 stop mmpd to fix the issue.