diff --git a/include/linux/bpf.h b/include/linux/bpf.h index 01e203964892..52b30e9ea431 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2917,7 +2917,7 @@ int bpf_check_uarg_tail_zero(bpfptr_t uaddr, size_t expected_size, int bpf_check(struct bpf_prog **fp, union bpf_attr *attr, bpfptr_t uattr, u32 uattr_size); #ifndef CONFIG_BPF_JIT_ALWAYS_ON -void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth); +int bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth); #endif struct btf *bpf_get_btf_vmlinux(void); diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index 8b018ff48875..63044ebe5721 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2394,13 +2394,17 @@ EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) #undef PROG_NAME_LIST #ifdef CONFIG_BPF_SYSCALL -void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) +int bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) { stack_depth = max_t(u32, stack_depth, 1); + /* Prevent out-of-bounds read to interpreters_args */ + if (stack_depth > MAX_BPF_STACK) + return -EINVAL; insn->off = (s16) insn->imm; insn->imm = interpreters_args[(round_up(stack_depth, 32) / 32) - 1] - __bpf_call_base_args; insn->code = BPF_JMP | BPF_CALL_ARGS; + return 0; } #endif #endif diff --git a/kernel/bpf/fixups.c b/kernel/bpf/fixups.c index fba9e8c00878..df8f48091321 100644 --- a/kernel/bpf/fixups.c +++ b/kernel/bpf/fixups.c @@ -1416,7 +1416,12 @@ int bpf_fixup_call_args(struct bpf_verifier_env *env) depth = get_callee_stack_depth(env, insn, i); if (depth < 0) return depth; - bpf_patch_call_args(insn, depth); + err = bpf_patch_call_args(insn, depth); + if (err) { + verbose(env, "stack depth %d exceeds interpreter stack depth limit\n", + depth); + return err; + } } err = 0; #endif