From patchwork Thu Jul 11 15:18:38 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Puranjay Mohan X-Patchwork-Id: 13730809 X-Patchwork-Delegate: bpf@iogearbox.net Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CD2FDAD39; Thu, 11 Jul 2024 15:18:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720711134; cv=none; b=jjtkAXjy/gb6hA9FbnV/1bAebLMwLENCR5yt0kYxcqiIJ04SCzRWc8s2iiJVJULIZ+W4MD426i/ga4s3Dtg19O7y/k8N5BIqTuB5d3Xmu6BL/z1mUb9piBjVO9J8bnEE7uY3k97NqNY7hN2rmICpVEwDp7ARZ5H1ntnFooaUkfE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720711134; c=relaxed/simple; bh=lgCOm4ajbDC2WkfLf4CQCsarvwNbzKn4RzkwvqZn7DU=; h=From:To:Subject:Date:Message-Id:MIME-Version; b=UsJYwcYYBmxZhlhbGlb4KLgNEuuyTaRRekGYhstN8PXjRMIRbUB536UNLaOfHN09lkTkQX0EzaqCzb4XNw+WDQiigBu9ARtGixVXdJT/6GChZ+4xSZNMljEjdgwfbUAMajrWRKv2PSowyhIlvK4Zf0pguURPAJ0zvz+OFT+k3qU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Vod8Zieg; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Vod8Zieg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 11AF8C116B1; Thu, 11 Jul 2024 15:18:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1720711134; bh=lgCOm4ajbDC2WkfLf4CQCsarvwNbzKn4RzkwvqZn7DU=; h=From:To:Subject:Date:From; b=Vod8ZiegXAS+eCiFiA43QsxWkAF/BzmyEwLYmS7RVWpJcK0w9RQdWpdiqFL8KaoV9 NEEGpnz7pdk9LnQyW0rLLbt4AZeTEP9fr3ZQLyYc7GsPfybfudZ1y+NIwNmKhkpoLK IFXOGPBM+hySYlni/Cz56k8OQRr+yz9xU9FcfNF7cgXURK8AFxE5ZX0AhrSSmKFihf crVzC9tGc5U3+HIqOBKco07HiYdRimdnv567fBWdvLBrIMXv/Cl18XkexN1B+umB1d u16P4vzgQNPQqlMjLWNYGEn6VpH8wMuvQSdcExkwmgQj2Altc4g33pmIaSmqpYN9U0 Au8wWBr2wJAKg== From: Puranjay Mohan To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Puranjay Mohan , Xu Kuohai , Catalin Marinas , Will Deacon , Jean-Philippe Brucker , bpf@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH bpf] bpf, arm64: fix trampoline for BPF_TRAMP_F_CALL_ORIG Date: Thu, 11 Jul 2024 15:18:38 +0000 Message-Id: <20240711151838.43469-1-puranjay@kernel.org> X-Mailer: git-send-email 2.40.1 Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: bpf@iogearbox.net When BPF_TRAMP_F_CALL_ORIG is set, the trampoline calls __bpf_tramp_enter() and __bpf_tramp_exit() functions, passing them the struct bpf_tramp_image *im pointer as an argument in R0. The trampoline generation code uses emit_addr_mov_i64() to emit instructions for moving the bpf_tramp_image address into R0, but emit_addr_mov_i64() assumes the address to be in the vmalloc() space and uses only 48 bits. Because bpf_tramp_image is allocated using kzalloc(), its address can use more than 48-bits, in this case the trampoline 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. Fixes: efc9909fdce0 ("bpf, arm64: Add bpf trampoline for arm64") Closes: https://lore.kernel.org/all/SJ0PR15MB461564D3F7E7A763498CA6A8CBDB2@SJ0PR15MB4615.namprd15.prod.outlook.com/ Signed-off-by: Puranjay Mohan --- arch/arm64/net/bpf_jit_comp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c index 720336d28856..1bf483ec971d 100644 --- a/arch/arm64/net/bpf_jit_comp.c +++ b/arch/arm64/net/bpf_jit_comp.c @@ -2141,7 +2141,7 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im, emit(A64_STR64I(A64_R(20), A64_SP, regs_off + 8), ctx); if (flags & BPF_TRAMP_F_CALL_ORIG) { - emit_addr_mov_i64(A64_R(0), (const u64)im, ctx); + emit_a64_mov_i64(A64_R(0), (const u64)im, ctx); emit_call((const u64)__bpf_tramp_enter, ctx); } @@ -2185,7 +2185,7 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im, if (flags & BPF_TRAMP_F_CALL_ORIG) { im->ip_epilogue = ctx->ro_image + ctx->idx; - emit_addr_mov_i64(A64_R(0), (const u64)im, ctx); + emit_a64_mov_i64(A64_R(0), (const u64)im, ctx); emit_call((const u64)__bpf_tramp_exit, ctx); }