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authorFlorian Weimer <fweimer@redhat.com>2019-06-12 14:48:33 +0200
committerFlorian Weimer <fweimer@redhat.com>2019-06-12 14:48:33 +0200
commitcfa611447b44d2fa1cb3d8f853b6f3f75ade366a (patch)
tree52f89d4d9ddf45959ab478d4701b80e42e66614f /libio
parent744e829637162bb7d5029632aacf341c64b86990 (diff)
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libio: freopen of default streams crashes in old programs [BZ #24632]
As seen with very old i386 GCC binaries.
Diffstat (limited to 'libio')
-rw-r--r--libio/freopen.c2
-rw-r--r--libio/libioP.h5
2 files changed, 6 insertions, 1 deletions
diff --git a/libio/freopen.c b/libio/freopen.c
index 17b00258cd..82e39f5028 100644
--- a/libio/freopen.c
+++ b/libio/freopen.c
@@ -62,7 +62,7 @@ freopen (const char *filename, const char *mode, FILE *fp)
 	 to the old libio may be passed into shared C library and wind
 	 up here. */
       _IO_old_file_close_it (fp);
-      _IO_JUMPS_FILE_plus (fp) = &_IO_old_file_jumps;
+      _IO_JUMPS_FUNC_UPDATE (fp, &_IO_old_file_jumps);
       result = _IO_old_file_fopen (fp, gfilename, mode);
     }
   else
diff --git a/libio/libioP.h b/libio/libioP.h
index 66afaa8968..afa46cc519 100644
--- a/libio/libioP.h
+++ b/libio/libioP.h
@@ -108,9 +108,14 @@
   (IO_validate_vtable                                                   \
    (*(struct _IO_jump_t **) ((void *) &_IO_JUMPS_FILE_plus (THIS)	\
 			     + (THIS)->_vtable_offset)))
+# define _IO_JUMPS_FUNC_UPDATE(THIS, VTABLE)				\
+  (*(const struct _IO_jump_t **) ((void *) &_IO_JUMPS_FILE_plus (THIS)	\
+				  + (THIS)->_vtable_offset) = (VTABLE))
 # define _IO_vtable_offset(THIS) (THIS)->_vtable_offset
 #else
 # define _IO_JUMPS_FUNC(THIS) (IO_validate_vtable (_IO_JUMPS_FILE_plus (THIS)))
+# define _IO_JUMPS_FUNC_UPDATE(THIS, VTABLE) \
+  (_IO_JUMPS_FILE_plus (THIS) = (VTABLE))
 # define _IO_vtable_offset(THIS) 0
 #endif
 #define _IO_WIDE_JUMPS_FUNC(THIS) _IO_WIDE_JUMPS(THIS)