Commit e363d24c authored Aug 01, 2016 by Mike Travis Committed by Ingo Molnar Aug 10, 2016

x86/platform/UV: Fix bug with iounmap() of the UV4 EFI System Table causing a crash



Save the uv_systab::size field before doing the iounmap()
of the struct pointer, to avoid a NULL dereference crash.

Tested-by: Frank Ramsay <framsay@sgi.com>
Tested-by: John Estabrook <estabrook@sgi.com>
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Dimitri Sivanich <sivanich@sgi.com>
Reviewed-by: Nathan Zimmer <nzimmer@sgi.com>
Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andrew Banman <abanman@sgi.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russ Anderson <rja@sgi.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20160801184050.250424783@asylum.americas.sgi.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>

parent 054f621f

arch/x86/platform/uv/bios_uv.c

+5 −3

Original line number	Diff line number	Diff line
		@@ -199,12 +199,14 @@ void uv_bios_init(void)
		return;
		}

		/* Starting with UV4 the UV systab size is variable */
		if (uv_systab->revision >= UV_SYSTAB_VERSION_UV4) {
		int size = uv_systab->size;

		iounmap(uv_systab);
		uv_systab = ioremap(efi.uv_systab, uv_systab->size);
		uv_systab = ioremap(efi.uv_systab, size);
		if (!uv_systab) {
		pr_err("UV: UVsystab: ioremap(%d) failed!\n",
		uv_systab->size);
		pr_err("UV: UVsystab: ioremap(%d) failed!\n", size);
		return;
		}
		}