4.9-stable review patch. If anyone has any objections, please let me know.
------------------ From: Joerg Roedel <[email protected]> commit 5ed386ec09a5d75bcf073967e55e895c2607a5c3 upstream. When this function fails it just sends a SIGSEGV signal to user-space using force_sig(). This signal is missing essential information about the cause, e.g. the trap_nr or an error code. Fix this by propagating the error to the only caller of mpx_handle_bd_fault(), do_bounds(), which sends the correct SIGSEGV signal to the process. Signed-off-by: Joerg Roedel <[email protected]> Cc: Andy Lutomirski <[email protected]> Cc: Borislav Petkov <[email protected]> Cc: Brian Gerst <[email protected]> Cc: Dave Hansen <[email protected]> Cc: Denys Vlasenko <[email protected]> Cc: H. Peter Anvin <[email protected]> Cc: Josh Poimboeuf <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Fixes: fe3d197f84319 ('x86, mpx: On-demand kernel allocation of bounds tables') Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- arch/x86/mm/mpx.c | 10 +--------- 1 file changed, 1 insertion(+), 9 deletions(-) --- a/arch/x86/mm/mpx.c +++ b/arch/x86/mm/mpx.c @@ -525,15 +525,7 @@ int mpx_handle_bd_fault(void) if (!kernel_managing_mpx_tables(current->mm)) return -EINVAL; - if (do_mpx_bt_fault()) { - force_sig(SIGSEGV, current); - /* - * The force_sig() is essentially "handling" this - * exception, so we do not pass up the error - * from do_mpx_bt_fault(). - */ - } - return 0; + return do_mpx_bt_fault(); } /*
