From patchwork Mon Jul 18 03:31:51 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nicolas Pitre X-Patchwork-Id: 9234011 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id BA53560756 for ; Mon, 18 Jul 2016 03:33:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id ADBDE254F7 for ; Mon, 18 Jul 2016 03:33:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id A21D926B39; Mon, 18 Jul 2016 03:33:58 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 34EC7254F7 for ; Mon, 18 Jul 2016 03:33:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751722AbcGRDca (ORCPT ); Sun, 17 Jul 2016 23:32:30 -0400 Received: from alt42.smtp-out.videotron.ca ([23.233.128.29]:47470 "EHLO alt42.smtp-out.videotron.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751530AbcGRDcN (ORCPT ); Sun, 17 Jul 2016 23:32:13 -0400 Received: from yoda.home ([96.23.157.65]) by Videotron with SMTP id OzHubpSbLcMN9OzHvbTNDN; Sun, 17 Jul 2016 23:32:11 -0400 X-Authority-Analysis: v=2.1 cv=YqOvP9sX 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=hS0c0Ahk9r2mtBNNZc4A:9 a=xpg3k_p32zQFYyYe:21 a=fsWtuSav939eIczi:21 a=cvBusfyB2V15izCimMoJ:22 Received: from xanadu.home (xanadu.home [192.168.2.2]) by yoda.home (Postfix) with ESMTP id 9521A2DA0660; Sun, 17 Jul 2016 23:32:08 -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 v2 05/10] binfmt_flat: use proper user space accessors with relocs processing code Date: Sun, 17 Jul 2016 23:31:51 -0400 Message-Id: <1468812716-30537-6-git-send-email-nicolas.pitre@linaro.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1468812716-30537-1-git-send-email-nicolas.pitre@linaro.org> References: <1468812716-30537-1-git-send-email-nicolas.pitre@linaro.org> X-CMAE-Envelope: MS4wfPjNvWLaTZrxFGfdogfd5bZ2bxYMEVW/Y7eBWw7DoG86z7D59DnYKAYONw6lSwHXSntK+DhDI1RjcgtahX+rLVA9zFqdqV9VI4N+kFreLjeZNhai0c34 48Io64AGGxlXlcSsrfqYvYKnf+oxyvHlZjmujsMumrm9a4Ir2oNmJGh5fcimL1VZwZN3dh/G/3LbTyqAtZpd371Y8er5dVSVAdQnfFPp+rPyA7vOFyyOvgvI 8vTdtQKhhVuNKcNSE1aCh3K3az7G6nrPVsMW4723mao4Li6wfJ/KPsm86qDbHdTbfVEHfvYTdbnHxnKQwt1VZQ== Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- 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(-) 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 9538901fe8..fc0ee3ed5d 100644 --- a/fs/binfmt_flat.c +++ b/fs/binfmt_flat.c @@ -438,7 +438,7 @@ 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; @@ -600,7 +600,7 @@ 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; @@ -625,7 +625,7 @@ 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; @@ -718,15 +718,20 @@ 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; } } } @@ -743,19 +748,21 @@ 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; /* Get the address of the pointer to be 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; }