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Patch "parisc: Fix kernel crash with reversed copy_from_user()" has been added to the 4.4-stable tree

PATCH [email protected] 1 participant 1 message Apr 12, 2016

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This is a note to let you know that I've just added the patch titled

parisc: Fix kernel crash with reversed copy_from_user()

to the 4.4-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
parisc-fix-kernel-crash-with-reversed-copy_from_user.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From ef72f3110d8b19f4c098a0bff7ed7d11945e70c6 Mon Sep 17 00:00:00 2001

From: Helge Deller <[email protected]>
Date: Fri, 8 Apr 2016 18:18:48 +0200
Subject: parisc: Fix kernel crash with reversed copy_from_user()

From: Helge Deller <[email protected]>

commit ef72f3110d8b19f4c098a0bff7ed7d11945e70c6 upstream.

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.

---
 arch/parisc/kernel/traps.c |    3 +++
 1 file changed, 3 insertions(+)
arch/parisc/kernel/traps.c +3 -0
@@ -798,6 +798,9 @@ void notrace handle_interruption(int cod
 
 	    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);
 	    }

Patches currently in stable-queue which might be from [email protected] are

queue-4.4/parisc-fix-kernel-crash-with-reversed-copy_from_user.patch queue-4.4/parisc-unbreak-handling-exceptions-from-kernel-modules.patch queue-4.4/parisc-avoid-function-pointers-for-kernel-exception-routines.patch