1.5 KiB
CVE-2024-43840
Description
In the Linux kernel, the following vulnerability has been resolved:bpf, arm64: Fix trampoline for BPF_TRAMP_F_CALL_ORIGWhen BPF_TRAMP_F_CALL_ORIG is set, the trampoline calls__bpf_tramp_enter() and __bpf_tramp_exit() functions, passing themthe struct bpf_tramp_image *im pointer as an argument in R0.The trampoline generation code uses emit_addr_mov_i64() to emitinstructions for moving the bpf_tramp_image address into R0, butemit_addr_mov_i64() assumes the address to be in the vmalloc() spaceand uses only 48 bits. Because bpf_tramp_image is allocated usingkzalloc(), its address can use more than 48-bits, in this case thetrampoline will pass an invalid address to __bpf_tramp_enter/exit()causing a kernel crash.Fix this by using emit_a64_mov_i64() in place of emit_addr_mov_i64()as it can work with addresses that are greater than 48-bits.
POC
Reference
No PoCs from references.