CVE-2023-53634

Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)

Description The Linux kernel contains a flaw related to Branch Target Identification (BTI) on the arm64 architecture. Specifically, when using BPF trampolines with the BPF TRAMP F CALL ORIG flag, a BTI exception can be triggered if the instruction following the call site is not a PACIASP instruction. This occurs because the trampoline uses BLR to return, and BTI-enabled kernels require a PACIASP instruction after the call site for safe branching. The issue arises when the call site is not followed by a PACIASP or BTI instruction. A fault log was provided demonstrating the BTI exception occurring during a test program execution. The root cause is that the JIT compiler does not always place a PACIASP instruction after the call site in BPF programs, leading to the BTI error.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.