rpms/glibc
3
0
Fork 0
Code Issues Pull Requests Releases Wiki Activity

Resolves: #1326903

Browse Source 
Fix fork redirection in libpthread
This commit is contained in:
Florian Weimer 2016-06-02 12:50:28 +02:00
parent 2d5168f40a
commit 7a43147883
2 changed files with 76 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

73
glibc-rh1326903.patch Normal file
View File

@ -0,0 +1,73 @@
commit f06f3f05b48c72e2c9b0fa78671f94fd22d67da8
Author: Florian Weimer <fweimer@redhat.com>
Date: Wed Jun 1 07:14:42 2016 +0200
fork in libpthread cannot use IFUNC resolver [BZ #19861]
This commit only addresses the fork case, the vfork case has to be a
tail call, which is why the generic code needs an IFUNC resolver
there.
diff --git a/nptl/pt-fork.c b/nptl/pt-fork.c
index b65d6b4..db9b61d 100644
--- a/nptl/pt-fork.c
+++ b/nptl/pt-fork.c
@@ -25,33 +25,14 @@
the historical ABI requires it. For static linking, there is no need to
provide anything here--the libc version will be linked in. For shared
library ABI compatibility, there must be __fork and fork symbols in
- libpthread.so; so we define them using IFUNC to redirect to the libc
- function. */
+ libpthread.so.
-#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
-
-# if HAVE_IFUNC
-
-static __typeof (fork) *
-__attribute__ ((used))
-fork_resolve (void)
-{
- return &__libc_fork;
-}
+ With an IFUNC resolver, it would be possible to avoid the
+ indirection, but the IFUNC resolver might run before the
+ __libc_fork symbol has been relocated, in which case the IFUNC
+ resolver would not be able to provide the correct address. */
-# ifdef HAVE_ASM_SET_DIRECTIVE
-# define DEFINE_FORK(name) \
- asm (".set " #name ", fork_resolve\n" \
- ".globl " #name "\n" \
- ".type " #name ", %gnu_indirect_function");
-# else
-# define DEFINE_FORK(name) \
- asm (#name " = fork_resolve\n" \
- ".globl " #name "\n" \
- ".type " #name ", %gnu_indirect_function");
-# endif
-
-# else /* !HAVE_IFUNC */
+#if SHLIB_COMPAT (libpthread, GLIBC_2_0, GLIBC_2_22)
static pid_t __attribute__ ((used))
fork_compat (void)
@@ -59,14 +40,10 @@ fork_compat (void)
return __libc_fork ();
}
-# define DEFINE_FORK(name) strong_alias (fork_compat, name)
-
-# endif /* HAVE_IFUNC */
-
-DEFINE_FORK (fork_ifunc)
-compat_symbol (libpthread, fork_ifunc, fork, GLIBC_2_0);
+strong_alias (fork_compat, fork_alias)
+compat_symbol (libpthread, fork_alias, fork, GLIBC_2_0);
-DEFINE_FORK (__fork_ifunc)
-compat_symbol (libpthread, __fork_ifunc, __fork, GLIBC_2_0);
+strong_alias (fork_compat, __fork_alias)
+compat_symbol (libpthread, __fork_alias, __fork, GLIBC_2_0);
#endif

3
glibc.spec
View File

@ -268,6 +268,7 @@ Patch1047: glibc-rh1330888.patch
Patch1048: glibc-rh1204521.patch
Patch1049: glibc-rh1282011.patch
Patch1050: glibc-rh1337140.patch
Patch1051: glibc-rh1326903.patch
##############################################################################
#
@ -735,6 +736,7 @@ microbenchmark tests on the system.
%patch1048 -p1
%patch1049 -p1
%patch1050 -p1
%patch1051 -p1
%patch0059 -p1
##############################################################################
@ -1957,6 +1959,7 @@ rm -f *.filelist*
%changelog
* Thu Jun 2 2016 Florian Weimer <fweimer@redhat.com> - 2.22-17
- CVE-2016-4429: stack overflow in Sun RPC clntudp_call (#1337140)
- Fix fork redirection in libpthread (#1326903)
* Wed May 11 2016 Florian Weimer <fweimer@redhat.com> - 2.22-16
- Back out dlsym (RTLD_NEXT)/dlerror change (#1333945)