From patchwork Thu Feb 13 13:12:12 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiayuan Chen X-Patchwork-Id: 864966 Received: from m16.mail.163.com (m16.mail.163.com [117.135.210.4]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4D8D723F41B; Thu, 13 Feb 2025 13:13:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.4 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739452398; cv=none; b=Ix6ECWOSMw2onKjJCRPnoZe/buW60HlWRFkoddCklEuUAEqmfAyt8ifHTVpi8vgBNSFh9Q0uSSrhmhsper3p+6uvN22SWzgPLMv3zX3bpCAuLvXXmaE+S0vVO8fWaAUj1gyA22m7+KKEeQ0ieQTkOUydBt2kDm4t6q7FalbcI9U= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739452398; c=relaxed/simple; bh=r3XU+DGNm90//yQ3AsPpyzLkR4el0EYOuVM2HcyiGqA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=a/tmuvfjDdjrGLFF1+Ufj9pmSpIClXTH8akNZKevZNgfT5mnfPm7s605DyorkoDTbe8LDcNEAGVx7TRde8NX/Yyt9QkuPC9eBbGZmmoWyAnVmjJIhO/9qS4mubG1O+DJhjM2isphKFzjJFXtBYRDV+CAy83bSAXb/OAyiA8sIc4= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=fdO3sUcK; arc=none smtp.client-ip=117.135.210.4 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="fdO3sUcK" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-ID:MIME-Version; bh=Y8v0K eZhBbmue/Fp6RVZC0XefbCMdD2hVwAYwi82vIs=; b=fdO3sUcK513OgSwKNnR2j jsWMj61Xbz2HrHNbl9wrginTWGW1+sY/9mtrkQnWtOjTfPiClP/sAtBIther7Hyd jnOachWQEbodwy+XLIpBsPyx8a+0lFvVzdksOuAIRham6z2iFwhMpsbAMsYNWsYR rlrvlmfeRILrpuNi+aUPzo= Received: from localhost.localdomain (unknown []) by gzga-smtp-mtada-g1-3 (Coremail) with SMTP id _____wD3N8qv761nJPMJMA--.27324S3; Thu, 13 Feb 2025 21:12:19 +0800 (CST) From: Jiayuan Chen To: bpf@vger.kernel.org, ast@kernel.org Cc: linux-kselftest@vger.kernel.org, daniel@iogearbox.net, john.fastabend@gmail.com, andrii@kernel.org, martin.lau@linux.dev, eddyz87@gmail.com, song@kernel.org, yonghong.song@linux.dev, kpsingh@kernel.org, sdf@fomichev.me, haoluo@google.com, jolsa@kernel.org, mykolal@fb.com, shuah@kernel.org, Jiayuan Chen , syzbot+d2a2c639d03ac200a4f1@syzkaller.appspotmail.com Subject: [PATCH bpf-next v2 1/3] bpf: Fix array bounds error with may_goto Date: Thu, 13 Feb 2025 21:12:12 +0800 Message-ID: <20250213131214.164982-2-mrpre@163.com> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250213131214.164982-1-mrpre@163.com> References: <20250213131214.164982-1-mrpre@163.com> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-CM-TRANSID: _____wD3N8qv761nJPMJMA--.27324S3 X-Coremail-Antispam: 1Uf129KBjvJXoWxJw1xZFyxKr4DAFy5GFy8Krg_yoW5tFyxpF 4DKFy7Cr48ta1Ik3sxCF4xurW5Jrs5tw17GanrJ348Ja1jqr4kCr15KFyrXryaqrn7Kw4r ZF1j9rnxtay7u3DanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0zEcTmxUUUUU= X-CM-SenderInfo: xpus2vi6rwjhhfrp/1tbiWxzyp2et6WvVuwAAs0 may_goto uses an additional 8 bytes on the stack, which causes the interpreters[] array to go out of bounds when calculating index by stack_size. 1. If a BPF program is rewritten, re-evaluate the stack size. For non-JIT cases, reject loading directly. 2. For non-JIT cases, calculating interpreters[idx] may still cause out-of-bounds array access, and just warn about it. 3. For jit_requested cases, the execution of bpf_func also needs to be warned. So Move the definition of function __bpf_prog_ret0_warn out of the macro definition CONFIG_BPF_JIT_ALWAYS_ON Reported-by: syzbot+d2a2c639d03ac200a4f1@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/0000000000000f823606139faa5d@google.com/ Fixes: 011832b97b311 ("bpf: Introduce may_goto instruction") Signed-off-by: Jiayuan Chen --- kernel/bpf/core.c | 18 ++++++++++++++---- kernel/bpf/verifier.c | 7 +++++++ 2 files changed, 21 insertions(+), 4 deletions(-) diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c index da729cbbaeb9..59291261f825 100644 --- a/kernel/bpf/core.c +++ b/kernel/bpf/core.c @@ -2269,6 +2269,9 @@ EVAL6(PROG_NAME_LIST, 32, 64, 96, 128, 160, 192) EVAL6(PROG_NAME_LIST, 224, 256, 288, 320, 352, 384) EVAL4(PROG_NAME_LIST, 416, 448, 480, 512) }; + +#define MAX_INTERPRETERS_CALLBACK (sizeof(interpreters) / sizeof(*interpreters)) + #undef PROG_NAME_LIST #define PROG_NAME_LIST(stack_size) PROG_NAME_ARGS(stack_size), static __maybe_unused @@ -2290,17 +2293,18 @@ void bpf_patch_call_args(struct bpf_insn *insn, u32 stack_depth) insn->code = BPF_JMP | BPF_CALL_ARGS; } #endif -#else +#endif + static unsigned int __bpf_prog_ret0_warn(const void *ctx, const struct bpf_insn *insn) { /* If this handler ever gets executed, then BPF_JIT_ALWAYS_ON - * is not working properly, so warn about it! + * is not working properly, or interpreter is being used when + * prog->jit_requested is not 0, so warn about it! */ WARN_ON_ONCE(1); return 0; } -#endif bool bpf_prog_map_compatible(struct bpf_map *map, const struct bpf_prog *fp) @@ -2380,8 +2384,14 @@ static void bpf_prog_select_func(struct bpf_prog *fp) { #ifndef CONFIG_BPF_JIT_ALWAYS_ON u32 stack_depth = max_t(u32, fp->aux->stack_depth, 1); + u32 idx = (round_up(stack_depth, 32) / 32) - 1; - fp->bpf_func = interpreters[(round_up(stack_depth, 32) / 32) - 1]; + if (!fp->jit_requested) { + WARN_ON_ONCE(idx >= MAX_INTERPRETERS_CALLBACK); + fp->bpf_func = interpreters[idx]; + } else { + fp->bpf_func = __bpf_prog_ret0_warn; + } #else fp->bpf_func = __bpf_prog_ret0_warn; #endif diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 9971c03adfd5..fcd302904ba0 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -21882,6 +21882,13 @@ static int do_misc_fixups(struct bpf_verifier_env *env) if (subprogs[cur_subprog + 1].start == i + delta + 1) { subprogs[cur_subprog].stack_depth += stack_depth_extra; subprogs[cur_subprog].stack_extra = stack_depth_extra; + + stack_depth = subprogs[cur_subprog].stack_depth; + if (stack_depth > MAX_BPF_STACK && !prog->jit_requested) { + verbose(env, "stack size %d(extra %d) is too large\n", + stack_depth, stack_depth_extra); + return -EINVAL; + } cur_subprog++; stack_depth = subprogs[cur_subprog].stack_depth; stack_depth_extra = 0;