commit: cb51c818a0d2b2f1a64e084411ac5717ebb3ef38
Author: Mike Frysinger <vapier <AT> gentoo <DOT> org>
AuthorDate: Wed Mar 30 03:44:29 2016 +0000
Commit: Mike Frysinger <vapier <AT> gentoo <DOT> org>
CommitDate: Wed Mar 30 03:46:35 2016 +0000
URL: https://gitweb.gentoo.org/repo/gentoo.git/commit/?id=cb51c818
sys-apps/sandbox: fix crashes w/some ELFs #578524
.../sandbox/files/sandbox-2.11-exec-hash.patch | 96 ++++++++++++++++++++++
...{sandbox-2.11.ebuild => sandbox-2.11-r1.ebuild} | 1 +
2 files changed, 97 insertions(+)
diff --git a/sys-apps/sandbox/files/sandbox-2.11-exec-hash.patch
b/sys-apps/sandbox/files/sandbox-2.11-exec-hash.patch
new file mode 100644
index 0000000..8a4cd9b
--- /dev/null
+++ b/sys-apps/sandbox/files/sandbox-2.11-exec-hash.patch
@@ -0,0 +1,96 @@
+From e11815bb7f0656f39e122073e0e3284ec7f5d021 Mon Sep 17 00:00:00 2001
+From: Mike Frysinger <[email protected]>
+Date: Tue, 29 Mar 2016 23:35:44 -0400
+Subject: [PATCH] libsandbox: fix symtab walking with some ELFs
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+The strtab assumption works if there is no SysV hash table.
+Add logic to handle that scenario.
+
+URL: https://bugs.gentoo.org/578524
+Reported-by: Toralf Förster <[email protected]>
+Signed-off-by: Mike Frysinger <[email protected]>
+---
+ libsandbox/wrapper-funcs/__wrapper_exec.c | 30 +++++++++++++++++-------------
+ 1 file changed, 17 insertions(+), 13 deletions(-)
+
+diff --git a/libsandbox/wrapper-funcs/__wrapper_exec.c
b/libsandbox/wrapper-funcs/__wrapper_exec.c
+index f7f51ab..d372366 100644
+--- a/libsandbox/wrapper-funcs/__wrapper_exec.c
++++ b/libsandbox/wrapper-funcs/__wrapper_exec.c
+@@ -83,10 +83,10 @@ static bool sb_check_exec(const char *filename, char
*const argv[])
+ ({ \
+ Elf##n##_Ehdr *ehdr = (void *)elf; \
+ Elf##n##_Phdr *phdr = (void *)(elf + ehdr->e_phoff); \
+- Elf##n##_Addr vaddr, filesz, vsym = 0, vstr = 0; \
+- Elf##n##_Off offset, symoff = 0, stroff = 0; \
++ Elf##n##_Addr vaddr, filesz, vsym = 0, vstr = 0, vhash = 0; \
++ Elf##n##_Off offset, symoff = 0, stroff = 0, hashoff = 0; \
+ Elf##n##_Dyn *dyn; \
+- Elf##n##_Sym *sym; \
++ Elf##n##_Sym *sym, *symend; \
+ uint##n##_t ent_size = 0, str_size = 0; \
+ bool dynamic = false; \
+ size_t i; \
+@@ -106,6 +106,7 @@ static bool sb_check_exec(const char *filename, char
*const argv[])
+ case DT_SYMENT: ent_size = dyn->d_un.d_val;
break; \
+ case DT_STRTAB: vstr = dyn->d_un.d_val; break; \
+ case DT_STRSZ: str_size = dyn->d_un.d_val;
break; \
++ case DT_HASH: vhash = dyn->d_un.d_val; break;
\
+ } \
+ ++dyn; \
+ } \
+@@ -123,6 +124,8 @@ static bool sb_check_exec(const char *filename, char
*const argv[])
+ symoff = offset + (vsym - vaddr); \
+ if (vstr >= vaddr && vstr < vaddr + filesz) \
+ stroff = offset + (vstr - vaddr); \
++ if (vhash >= vaddr && vhash < vaddr + filesz) \
++ hashoff = offset + (vhash - vaddr); \
+ } \
+ \
+ /* Finally walk the symbol table. This should generally be
fast as \
+@@ -130,18 +133,20 @@ static bool sb_check_exec(const char *filename, char
*const argv[])
+ * out there do not export any symbols at all. \
+ */ \
+ if (symoff && stroff) { \
+- sym = (void *)(elf + symoff); \
++ /* Hash entries are always 32-bits. */ \
++ uint32_t *hashes = (void *)(elf + hashoff); \
+ /* Nowhere is the # of symbols recorded, or the size of
the symbol \
+- * table. Instead, we do what glibc does: assume that
the string \
+- * table always follows the symbol table. This seems
like a poor \
+- * assumption to make, but glibc has gotten by this
long. We could \
+- * rely on DT_HASH and walking all the buckets to find
the largest \
+- * symbol index, but that's also a bit hacky. \
++ * table. Instead, we do what glibc does: use the sysv
hash table \
++ * if it exists, else assume that the string table
always directly \
++ * follows the symbol table. This seems like a poor
assumption to \
++ * make, but glibc has gotten by this long. \
+ * \
+ * We don't sanity check the ranges here as you aren't
executing \
+ * corrupt programs in the sandbox. \
+ */ \
+- for (i = 0; i < (vstr - vsym) / ent_size; ++i) { \
++ sym = (void *)(elf + symoff); \
++ symend = vhash ? (sym + hashes[1]) : (void *)(elf +
stroff); \
++ while (sym < symend) { \
+ char *symname = (void *)(elf + stroff +
sym->st_name); \
+ if (ELF##n##_ST_VISIBILITY(sym->st_other) ==
STV_DEFAULT && \
+ sym->st_shndx != SHN_UNDEF && sym->st_shndx
< SHN_LORESERVE && \
+@@ -149,9 +154,8 @@ static bool sb_check_exec(const char *filename, char
*const argv[])
+ /* Minor optimization to avoid strcmp. */ \
+ symname[0] == '_' && symname[1] == '_') { \
+ /* Blacklist internal C library
symbols. */ \
+- size_t j; \
+- for (j = 0; j <
ARRAY_SIZE(libc_alloc_syms); ++j) \
+- if (!strcmp(symname,
libc_alloc_syms[j])) { \
++ for (i = 0; i <
ARRAY_SIZE(libc_alloc_syms); ++i) \
++ if (!strcmp(symname,
libc_alloc_syms[i])) { \
+ run_in_process = false;
\
+ goto use_trace; \
+ } \
+--
+2.7.4
+
diff --git a/sys-apps/sandbox/sandbox-2.11.ebuild
b/sys-apps/sandbox/sandbox-2.11-r1.ebuild
similarity index 97%
rename from sys-apps/sandbox/sandbox-2.11.ebuild
rename to sys-apps/sandbox/sandbox-2.11-r1.ebuild
index 0bbf588..8001316 100644
--- a/sys-apps/sandbox/sandbox-2.11.ebuild
+++ b/sys-apps/sandbox/sandbox-2.11-r1.ebuild
@@ -32,6 +32,7 @@ sandbox_death_notice() {
}
src_prepare() {
+ epatch "${FILESDIR}"/${P}-exec-hash.patch #578524
epatch_user
}
