From: Yazhou Tang <tangyazhou518@outlook.com> mainline inclusion from mainline-v7.1-rc5 commit 4314a44564eb1565349fed7a4192344c5f46fc85 category: bugfix bugzilla: https://atomgit.com/openeuler/kernel/issues/9492 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- The interpreters_args array only accommodates stack depths up to MAX_BPF_STACK (512 bytes). However, do_misc_fixups() may allow a larger stack depth if JIT is requested. If JIT compilation later fails and falls back to the interpreter, the verifier invokes bpf_patch_call_args() with this oversized stack depth. This causes a load-time out-of-bounds (OOB) read when calculating the interpreter function pointer index. Fix this by changing bpf_patch_call_args() to return an int and explicitly rejecting the JIT fallback (returning -EINVAL) if the stack depth exceeds MAX_BPF_STACK. Fixes: 1ea47e01ad6e ("bpf: add support for bpf_call to interpreter") Co-developed-by: Tianci Cao <ziye@zju.edu.cn> Signed-off-by: Tianci Cao <ziye@zju.edu.cn> Co-developed-by: Shenghao Yuan <shenghaoyuan0928@163.com> Signed-off-by: Shenghao Yuan <shenghaoyuan0928@163.com> Signed-off-by: Yazhou Tang <tangyazhou518@outlook.com> Acked-by: Xu Kuohai <xukuohai@huawei.com> Link: https://lore.kernel.org/r/20260506094714.419842-2-tangyazhou@zju.edu.cn Signed-off-by: Alexei Starovoitov <ast@kernel.org> Conflicts: kernel/bpf/core.c kernel/bpf/verifier.c kernel/bpf/fixups.c [ctx conflicts] Signed-off-by: Pu Lehui <pulehui@huawei.com> --- include/linux/bpf.h | 2 +- kernel/bpf/core.c | 6 +++++- kernel/bpf/verifier.c | 7 ++++++- 3 files changed, 12 insertions(+), 3 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index a4b0137a665c..264aa4fd340b 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -2562,7 +2562,7 @@ 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 f1dfff8dab07..e622c7368dc4 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2284,13 +2284,17 @@ 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 #else diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 61f64e7d6810..54fa6ff87b60 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -19138,7 +19138,12 @@ static int 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 -- 2.34.1