From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ard Biesheuvel Subject: [PATCH 1/4] bpf: account for freed JIT allocations in arch code Date: Sat, 17 Nov 2018 10:57:12 -0800 Message-ID: <20181117185715.25198-2-ard.biesheuvel@linaro.org> References: <20181117185715.25198-1-ard.biesheuvel@linaro.org> Cc: Ard Biesheuvel , Daniel Borkmann , Alexei Starovoitov , Rick Edgecombe , Eric Dumazet , Jann Horn , Kees Cook , Jessica Yu , Arnd Bergmann , Catalin Marinas , Will Deacon , Mark Rutland , Ralf Baechle , Paul Burton , James Hogan , Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , "David S. Miller" , linux-arm-kernel@lists.infradead.or To: linux-kernel@vger.kernel.org Return-path: Received: from mail-pf1-f196.google.com ([209.85.210.196]:37582 "EHLO mail-pf1-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726151AbeKRFOz (ORCPT ); Sun, 18 Nov 2018 00:14:55 -0500 Received: by mail-pf1-f196.google.com with SMTP id u3-v6so10252332pfm.4 for ; Sat, 17 Nov 2018 10:57:21 -0800 (PST) In-Reply-To: <20181117185715.25198-1-ard.biesheuvel@linaro.org> Sender: netdev-owner@vger.kernel.org List-ID: Commit ede95a63b5e84 ("bpf: add bpf_jit_limit knob to restrict unpriv allocations") added a call to bpf_jit_uncharge_modmem() to the routine bpf_jit_binary_free() which is called from the __weak bpf_jit_free(). This function is overridden by arches, some of which do not call bpf_jit_binary_free() to release the memory, and so the released memory is not accounted for, potentially leading to spurious allocation failures. So replace the direct calls to module_memfree() in the arch code with calls to bpf_jit_binary_free(). Signed-off-by: Ard Biesheuvel --- arch/mips/net/bpf_jit.c | 2 +- arch/powerpc/net/bpf_jit_comp.c | 2 +- arch/powerpc/net/bpf_jit_comp64.c | 5 +---- arch/sparc/net/bpf_jit_comp_32.c | 2 +- 4 files changed, 4 insertions(+), 7 deletions(-) diff --git a/arch/mips/net/bpf_jit.c b/arch/mips/net/bpf_jit.c index 4d8cb9bb8365..1b69897274a1 100644 --- a/arch/mips/net/bpf_jit.c +++ b/arch/mips/net/bpf_jit.c @@ -1264,7 +1264,7 @@ void bpf_jit_compile(struct bpf_prog *fp) void bpf_jit_free(struct bpf_prog *fp) { if (fp->jited) - module_memfree(fp->bpf_func); + bpf_jit_binary_free(bpf_jit_binary_hdr(fp)); bpf_prog_unlock_free(fp); } diff --git a/arch/powerpc/net/bpf_jit_comp.c b/arch/powerpc/net/bpf_jit_comp.c index d5bfe24bb3b5..a1ea1ea6b40d 100644 --- a/arch/powerpc/net/bpf_jit_comp.c +++ b/arch/powerpc/net/bpf_jit_comp.c @@ -683,7 +683,7 @@ void bpf_jit_compile(struct bpf_prog *fp) void bpf_jit_free(struct bpf_prog *fp) { if (fp->jited) - module_memfree(fp->bpf_func); + bpf_jit_binary_free(bpf_jit_binary_hdr(fp)); bpf_prog_unlock_free(fp); } diff --git a/arch/powerpc/net/bpf_jit_comp64.c b/arch/powerpc/net/bpf_jit_comp64.c index 50b129785aee..84c8f013a6c6 100644 --- a/arch/powerpc/net/bpf_jit_comp64.c +++ b/arch/powerpc/net/bpf_jit_comp64.c @@ -1024,11 +1024,8 @@ struct bpf_prog *bpf_int_jit_compile(struct bpf_prog *fp) /* Overriding bpf_jit_free() as we don't set images read-only. */ void bpf_jit_free(struct bpf_prog *fp) { - unsigned long addr = (unsigned long)fp->bpf_func & PAGE_MASK; - struct bpf_binary_header *bpf_hdr = (void *)addr; - if (fp->jited) - bpf_jit_binary_free(bpf_hdr); + bpf_jit_binary_free(bpf_jit_binary_hdr(fp)); bpf_prog_unlock_free(fp); } diff --git a/arch/sparc/net/bpf_jit_comp_32.c b/arch/sparc/net/bpf_jit_comp_32.c index a5ff88643d5c..01bda6bc9e7f 100644 --- a/arch/sparc/net/bpf_jit_comp_32.c +++ b/arch/sparc/net/bpf_jit_comp_32.c @@ -759,7 +759,7 @@ cond_branch: f_offset = addrs[i + filter[i].jf]; void bpf_jit_free(struct bpf_prog *fp) { if (fp->jited) - module_memfree(fp->bpf_func); + bpf_jit_binary_free(bpf_jit_binary_hdr(fp)); bpf_prog_unlock_free(fp); } -- 2.17.1