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authorFlorian Weimer <fweimer@redhat.com>2018-06-26 10:24:52 +0200
committerFlorian Weimer <fweimer@redhat.com>2018-06-26 10:24:52 +0200
commitc402355dfa7807b8e0adb27c009135a7e2b9f1b0 (patch)
tree24a50fd3ad75c969ed22e0c456f33ee75a6bd922 /libio/vtables.c
parentnss_files: Use struct scratch_buffer instead of extend_alloca [BZ #18023] (diff)
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libio: Disable vtable validation in case of interposition [BZ #23313]
Diffstat (limited to 'libio/vtables.c')
-rw-r--r--libio/vtables.c16
1 files changed, 16 insertions, 0 deletions
diff --git a/libio/vtables.c b/libio/vtables.c
index 9fd4ccf642..9df75668c8 100644
--- a/libio/vtables.c
+++ b/libio/vtables.c
@@ -71,3 +71,19 @@ _IO_vtable_check (void)
__libc_fatal ("Fatal error: glibc detected an invalid stdio handle\n");
}
+
+/* Some variants of libstdc++ interpose _IO_2_1_stdin_ etc. and
+ install their own vtables directly, without calling _IO_init or
+ other functions. Detect this by looking at the vtables values
+ during startup, and disable vtable validation in this case. */
+#ifdef SHARED
+__attribute__ ((constructor))
+static void
+check_stdfiles_vtables (void)
+{
+ if (_IO_2_1_stdin_.vtable != &_IO_file_jumps
+ || _IO_2_1_stdout_.vtable != &_IO_file_jumps
+ || _IO_2_1_stderr_.vtable != &_IO_file_jumps)
+ IO_set_accept_foreign_vtables (&_IO_vtable_check);
+}
+#endif