Messages in this thread Patch in this message | | | From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 153/172] x86/mpx: Correctly report do_mpx_bt_fault() failures to user-space | Date | Mon, 3 Jul 2017 15:35:33 +0200 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Joerg Roedel <jroedel@suse.de>
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 <jroedel@suse.de> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: fe3d197f84319 ('x86, mpx: On-demand kernel allocation of bounds tables') Link: http://lkml.kernel.org/r/1491488362-27198-1-git-send-email-joro@8bytes.org Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- 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(); } /*
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