From cfa611447b44d2fa1cb3d8f853b6f3f75ade366a Mon Sep 17 00:00:00 2001 From: Florian Weimer Date: Wed, 12 Jun 2019 14:48:33 +0200 Subject: libio: freopen of default streams crashes in old programs [BZ #24632] As seen with very old i386 GCC binaries. --- libio/freopen.c | 2 +- libio/libioP.h | 5 +++++ 2 files changed, 6 insertions(+), 1 deletion(-) (limited to 'libio') diff --git a/libio/freopen.c b/libio/freopen.c index 17b0025..82e39f5 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 66afaa8..afa46cc 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) -- cgit v1.1