main/linux-vserver: fix memory map on PIE executables

(cherry picked from commit 543ea1b7436f575c6125a8b33b2547e9bbcc2a39)

2 files changed, 73 insertions, 1 deletions

diff --git a/main/linux-vserver/APKBUILD b/main/linux-vserver/APKBUILD
index f65f98e2c5..08e3dfa3f5 100644
--- a/main/linux-vserver/APKBUILD
+++ b/main/linux-vserver/APKBUILD
@@ -3,7 +3,7 @@
 _flavor=vserver
 pkgname=linux-${_flavor}
 pkgver=3.4.63
-pkgrel=0
+pkgrel=1
 _vsver=vs2.3.3.9
 
 if [ "${pkgver##*.*.*}" = "$pkgver" ]; then
@@ -22,6 +22,7 @@ install=
 source="http://www.kernel.org/pub/linux/kernel/v3.x/linux-$_kernver.tar.xz
         http://www.kernel.org/pub/linux/kernel/v3.x/patch-$pkgver.xz
         patch-$pkgver-$_vsver.diff
+        aslr-pie.patch
         kernelconfig.x86
         kernelconfig.x86_64
         "
@@ -138,15 +139,18 @@ dev() {
 md5sums="967f72983655e2479f951195953e8480  linux-3.4.tar.xz
 44a633f8494b3e3008ace9e74c6b9e75  patch-3.4.63.xz
 296bcb44cdc4e776a938e203cbbd5151  patch-3.4.63-vs2.3.3.9.diff
+5901bfca41ac6a557e12b48115d3d1b2  aslr-pie.patch
 1fce2ef2e47d19c150ab0b2df3373a57  kernelconfig.x86
 b6a18f4cb2523bbd2500809e61172f8f  kernelconfig.x86_64"
 sha256sums="ff3dee6a855873d12487a6f4070ec2f7996d073019171361c955639664baa0c6  linux-3.4.tar.xz
 436422cc2c0ac6243632561955c3ecefd3150d0ba061943f45600c0674e4da89  patch-3.4.63.xz
 2d722df186395a3592928a7166962d503ae5bd726b47ee5eb9a60d39c39f159a  patch-3.4.63-vs2.3.3.9.diff
+37ad5b5f44fcc119f71c81e8cda376c13ecc04f785bd2e1892782def6f5cfae3  aslr-pie.patch
 e97b45a117671c5a87a9ba4a1f946125053eac078d297f61f9c8d4594acbf830  kernelconfig.x86
 d44d1a1be3402847f540cc0cfb201deec7084b4c516e592b92e115ab3f71d4b5  kernelconfig.x86_64"
 sha512sums="1c49b336750c9c2b49d21e54126f22a800367296be0d57e6df28b1532cbeba7fc3bdf4cfe27d9810576e76c2db2e9c2493f0804451c915137cb78d7aa61f236c  linux-3.4.tar.xz
 c8d4e56062e3f1bdbb3c3b46cd6db42f63e6b86c6a1a45d181eb0160a1c7ecca13928f61484f949d6c968e437f275d43bca035a44c742f78d2cf77db1bcca1aa  patch-3.4.63.xz
 26623fca09815baee653a8da5af46797bc0b54f250a09401ede64c71ad2c844a1b59e7a0c7fc024e5c9025ddf3109ef2d2aa49c3866daa9288861d0d326d7f83  patch-3.4.63-vs2.3.3.9.diff
+0314ff29551dfde45fe05d43cb571348d955b5338b33acb26e29fa80f73ef28f34bbdf01006e4aecee372f3863517357a99cdec08b183a8dd9121ee9d0314b2e  aslr-pie.patch
 f12f999c84f724a4ac20a736c7f56671e23b2a9ddce4b0576dc17d0b3e8f319f5c4bc40b58992eba75ace44148018d85de24b2516d0a83240cd0ca3803606eae  kernelconfig.x86
 4cf43a7fc609e9822919e5706f38c03ef72deae2eae6b7d4c4ca7f9f29bccd1f01c0d65660a0c5234df6c2123a1d0c797dbdcb57ca5559e39644704426657f3e  kernelconfig.x86_64"
diff --git a/main/linux-vserver/aslr-pie.patch b/main/linux-vserver/aslr-pie.patch
new file mode 100644
index 0000000000..8b907e447e
--- /dev/null
+++ b/main/linux-vserver/aslr-pie.patch
@@ -0,0 +1,68 @@
+From a72b1fccf6c7c54c7a3ceef525b615b26b38f4a4 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Timo=20Ter=C3=A4s?= <timo.teras@iki.fi>
+Date: Tue, 1 Oct 2013 13:46:04 +0300
+Subject: [PATCH 3.4.63-vanilla] fs/binfmt_elf: fix memory map for PIE applications
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+arch/x86/include/asm/elf.h comment says:
+"
+ELF_ET_DYN_BASE is the location that an ET_DYN program is loaded
+if exec'ed.  Typical use of this is to invoke "./ld.so someprog"
+to test out a new version of the loader.  We need to make sure
+that it is out of the way of the program that it will "exec",
+and that there is sufficient room for the brk.
+"
+
+In case we have main application linked as PIE, this will cause
+problems as the main program itself will go the memory location
+that allows very little heap.
+
+This fixes the loader to detect PIE application by checking if
+elf_interpreter is requested, and loads them to beginning of the
+address space instead of the specially crafted place for elf
+interpreter.
+
+Signed-off-by: Timo Teräs <timo.teras@iki.fi>
+---
+ fs/binfmt_elf.c | 17 ++++++++---------
+ 1 file changed, 8 insertions(+), 9 deletions(-)
+
+diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
+index a009b9e..b3723a2 100644
+--- a/fs/binfmt_elf.c
++++ b/fs/binfmt_elf.c
+@@ -790,20 +790,19 @@ static int load_elf_binary(struct linux_binprm *bprm, struct pt_regs *regs)
+                         * default mmap base, as well as whatever program they
+                         * might try to exec.  This is because the brk will
+                         * follow the loader, and is not movable.  */
++                       if (elf_interpreter)
++                               load_bias = 0x00400000UL;
++                       else
++                               load_bias = ELF_ET_DYN_BASE;
+ #ifdef CONFIG_ARCH_BINFMT_ELF_RANDOMIZE_PIE
+                        /* Memory randomization might have been switched off
+-                        * in runtime via sysctl.
+-                        * If that is the case, retain the original non-zero
+-                        * load_bias value in order to establish proper
+-                        * non-randomized mappings.
++                        * in runtime via sysctl or explicit setting of
++                        * ersonality flags.
+                         */
+                        if (current->flags & PF_RANDOMIZE)
+-                               load_bias = 0;
+-                       else
+-                               load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
+-#else
+-                       load_bias = ELF_PAGESTART(ELF_ET_DYN_BASE - vaddr);
++                               load_bias += (get_random_int() & STACK_RND_MASK) << PAGE_SHIFT;
+ #endif
++                       load_bias = ELF_PAGESTART(vaddr + load_bias);
+                }
+ 
+                error = elf_map(bprm->file, load_bias + vaddr, elf_ppnt,
+-- 
+1.8.4
+
+