From patchwork Wed Jul 20 19:22:36 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 72474 Delivered-To: patch@linaro.org Received: by 10.140.29.52 with SMTP id a49csp44372qga; Wed, 20 Jul 2016 12:24:56 -0700 (PDT) X-Received: by 10.98.2.208 with SMTP id 199mr67397424pfc.80.1469042696598; Wed, 20 Jul 2016 12:24:56 -0700 (PDT) Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id g9si4893904pfk.211.2016.07.20.12.24.56; Wed, 20 Jul 2016 12:24:56 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=fail (p=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754353AbcGTTX1 (ORCPT + 29 others); Wed, 20 Jul 2016 15:23:27 -0400 Received: from alt13.smtp-out.videotron.ca ([135.19.0.26]:34137 "EHLO alt12.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754760AbcGTTWu (ORCPT ); Wed, 20 Jul 2016 15:22:50 -0400 Received: from yoda.home ([96.23.157.65]) by Videotron with SMTP id Px4xbh5IVq3HFPx4yb4WQX; Wed, 20 Jul 2016 15:22:48 -0400 X-Authority-Analysis: v=2.1 cv=Q9lym9Ca c=1 sm=1 tr=0 a=keA3yYpnlypCNW5BNWqu+w==:117 a=keA3yYpnlypCNW5BNWqu+w==:17 a=L9H7d07YOLsA:10 a=9cW_t1CCXrUA:10 a=s5jvgZ67dGcA:10 a=cAmyUtKerLwA:10 a=KKAkSRfTAAAA:8 a=tBb2bbeoAAAA:8 a=hS0c0Ahk9r2mtBNNZc4A:9 a=dpbAhzR_p2l7Q4pB:21 a=Ok9BKEJE8sLYLVB3:21 a=cvBusfyB2V15izCimMoJ:22 a=Oj-tNtZlA1e06AYgeCfH:22 Received: from xanadu.home (xanadu.home [192.168.2.2]) by yoda.home (Postfix) with ESMTP id B4AB52DA0697; Wed, 20 Jul 2016 15:22:45 -0400 (EDT) From: Nicolas Pitre To: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Alexander Viro , David Howells , Greg Ungerer Subject: [PATCH v4 07/12] binfmt_flat: use proper user space accessors with relocs processing code Date: Wed, 20 Jul 2016 15:22:36 -0400 Message-Id: <1469042561-7360-8-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1469042561-7360-1-git-send-email-nicolas.pitre@linaro.org> References: <1469042561-7360-1-git-send-email-nicolas.pitre@linaro.org> X-CMAE-Envelope: MS4wfAwqQuvdPd5QqqFJ2FgWkadfyCanESe88jTfGzka6JMR0t0mms+LX0V6dKILqZuXtdsJdZ0ikm+LHEV2VH2Oox1ZBLobH8WhVj3sZM/8vv+yEshhF0b4 mMRYnY5sorJ2IwFRwCrgmn7CxtQpU0B8KBBbPPOwSbDD6ZZ6Mq+nO/WJzB7cVWqMJS+395es85M66S4w7lN1LGphLpPbIvRvXFvw2jYl5HZj0t1RHILV+3Hg T2oK60c8mNZ1AEtzjHqMlaHSarxd2n1GazayNl8d3iiLYZ2cs8B4E1dsAc8xof3BCpQD/0JugDWLamZH8wdx4A== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Relocs are fixed up in place in user space memory. The appropriate accessors are required for this code to work with an active MMU. The architecture specific handlers for ARM and M68K are also covered. SuperH and Xtensa are left out as they doesn't implement __get_user_unaligned() and __put_user_unaligned() yet. The other architectures that use BFLT don't have any MMU. Signed-off-by: Nicolas Pitre Reviewed-by: Greg Ungerer --- arch/arm/include/asm/flat.h | 5 +++-- arch/m68k/include/asm/flat.h | 5 +++-- fs/binfmt_flat.c | 31 +++++++++++++++++++------------ 3 files changed, 25 insertions(+), 16 deletions(-) -- 2.7.4 diff --git a/arch/arm/include/asm/flat.h b/arch/arm/include/asm/flat.h index e847d23351..acf1d14b89 100644 --- a/arch/arm/include/asm/flat.h +++ b/arch/arm/include/asm/flat.h @@ -8,8 +8,9 @@ #define flat_argvp_envp_on_stack() 1 #define flat_old_ram_flag(flags) (flags) #define flat_reloc_valid(reloc, size) ((reloc) <= (size)) -#define flat_get_addr_from_rp(rp, relval, flags, persistent) ((void)persistent,get_unaligned(rp)) -#define flat_put_addr_at_rp(rp, val, relval) put_unaligned(val,rp) +#define flat_get_addr_from_rp(rp, relval, flags, persistent) \ + ({ unsigned long __val; __get_user_unaligned(__val, rp); __val; }) +#define flat_put_addr_at_rp(rp, val, relval) __put_user_unaligned(val, rp) #define flat_get_relocate_addr(rel) (rel) #define flat_set_persistent(relval, p) 0 diff --git a/arch/m68k/include/asm/flat.h b/arch/m68k/include/asm/flat.h index f9454b89a5..f3f592d03e 100644 --- a/arch/m68k/include/asm/flat.h +++ b/arch/m68k/include/asm/flat.h @@ -8,8 +8,9 @@ #define flat_argvp_envp_on_stack() 1 #define flat_old_ram_flag(flags) (flags) #define flat_reloc_valid(reloc, size) ((reloc) <= (size)) -#define flat_get_addr_from_rp(rp, relval, flags, p) get_unaligned(rp) -#define flat_put_addr_at_rp(rp, val, relval) put_unaligned(val,rp) +#define flat_get_addr_from_rp(rp, relval, flags, p) \ + ({ unsigned long __val; __get_user_unaligned(__val, rp); __val; }) +#define flat_put_addr_at_rp(rp, val, relval) __put_user_unaligned(val, rp) #define flat_get_relocate_addr(rel) (rel) static inline int flat_set_persistent(unsigned long relval, diff --git a/fs/binfmt_flat.c b/fs/binfmt_flat.c index 5dc7968a42..9deafb282d 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -419,7 +419,7 @@ static int load_flat_file(struct linux_binprm *bprm, unsigned long textpos, datapos, realdatastart; unsigned long text_len, data_len, bss_len, stack_len, full_data, flags; unsigned long len, memp, memp_size, extra, rlim; - unsigned long *reloc, *rp; + unsigned long __user *reloc, *rp; struct inode *inode; int i, rev, relocs; loff_t fpos; @@ -591,7 +591,7 @@ static int load_flat_file(struct linux_binprm *bprm, goto err; } - reloc = (unsigned long *) + reloc = (unsigned long __user *) (datapos + (ntohl(hdr->reloc_start) - text_len)); memp = realdatastart; memp_size = len; @@ -616,7 +616,7 @@ static int load_flat_file(struct linux_binprm *bprm, MAX_SHARED_LIBS * sizeof(unsigned long), FLAT_DATA_ALIGN); - reloc = (unsigned long *) + reloc = (unsigned long __user *) (datapos + (ntohl(hdr->reloc_start) - text_len)); memp = textpos; memp_size = len; @@ -708,15 +708,20 @@ static int load_flat_file(struct linux_binprm *bprm, * image. */ if (flags & FLAT_FLAG_GOTPIC) { - for (rp = (unsigned long *)datapos; *rp != 0xffffffff; rp++) { - unsigned long addr; - if (*rp) { - addr = calc_reloc(*rp, libinfo, id, 0); + for (rp = (unsigned long __user *)datapos; ; rp++) { + unsigned long addr, rp_val; + if (get_user(rp_val, rp)) + return -EFAULT; + if (rp_val == 0xffffffff) + break; + if (rp_val) { + addr = calc_reloc(rp_val, libinfo, id, 0); if (addr == RELOC_FAILED) { ret = -ENOEXEC; goto err; } - *rp = addr; + if (put_user(addr, rp)) + return -EFAULT; } } } @@ -733,7 +738,7 @@ static int load_flat_file(struct linux_binprm *bprm, * __start to address 4 so that is okay). */ if (rev > OLD_FLAT_VERSION) { - unsigned long persistent = 0; + unsigned long __maybe_unused persistent = 0; for (i = 0; i < relocs; i++) { unsigned long addr, relval; @@ -742,12 +747,14 @@ static int load_flat_file(struct linux_binprm *bprm, * relocated (of course, the address has to be * relocated first). */ - relval = ntohl(reloc[i]); + if (get_user(relval, reloc + i)) + return -EFAULT; + relval = ntohl(relval); if (flat_set_persistent(relval, &persistent)) continue; addr = flat_get_relocate_addr(relval); - rp = (unsigned long *) calc_reloc(addr, libinfo, id, 1); - if (rp == (unsigned long *)RELOC_FAILED) { + rp = (unsigned long __user *)calc_reloc(addr, libinfo, id, 1); + if (rp == (unsigned long __user *)RELOC_FAILED) { ret = -ENOEXEC; goto err; }