parisc: Fix kernel crash with reversed copy_from_user()

PATCH New Helge Deller 1 participant 1 message Apr 8, 2016 PA-RISC architecture

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Helge Deller

author maintainer

2016-04-08 19:28 UTC #0 lore raw

PATCH 1/1 parisc: Fix kernel crash with reversed copy_from_user()

The kernel module testcase (lib/test_user_copy.c) exhibited a kernel crash on parisc if the parameters for copy_from_user were reversed ("illegal reversed copy_to_user" testcase).

Fix this potential crash by checking the fault handler if the faulting address is in the exception table.

Signed-off-by Helge Deller <[email protected]>

Cc [email protected]

Cc Kees Cook <[email protected]>

arch/parisc/kernel/traps.c +3 -0

index 16e0735..97d6b20 100644
@@ -795,6 +795,9 @@ void notrace handle_interruption(int code, struct pt_regs *regs)
 
 	    if (fault_space == 0 && !faulthandler_disabled())
 	    {
+		/* Clean up and return if in exception table. */
+		if (fixup_exception(regs))
+			return;
 		pdc_chassis_send_status(PDC_CHASSIS_DIRECT_PANIC);
 		parisc_terminate("Kernel Fault", regs, code, fault_address);
 	    }