An issue was discovered in the Linux kernel 5.4 and 5.5 through 5.5.6 on the AArch64 architecture. It ignores the top byte in the address passed to the brk system call, potentially moving the memory break downwards when the application expects it to move upwards, aka CID-dcde237319e6. This has been observed to cause heap corruption with the GNU C Library malloc implementation.
Created kernel tracking bugs for this issue:
Affects: fedora-all [bug 1814238]
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
The affected code was not introduced into any kernel versions shipped with Red Hat Enterprise Linux making this vulnerable not applicable to these platforms.
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):