Commit-ID: e363d24c2b997c421476c6aa00547edadf678efe Gitweb: http://git.kernel.org/tip/e363d24c2b997c421476c6aa00547edadf678efe Author: Mike Travis <tra...@sgi.com> AuthorDate: Mon, 1 Aug 2016 13:40:51 -0500 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Wed, 10 Aug 2016 15:55:38 +0200
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 <fram...@sgi.com> Tested-by: John Estabrook <estabr...@sgi.com> Signed-off-by: Mike Travis <tra...@sgi.com> Reviewed-by: Dimitri Sivanich <sivan...@sgi.com> Reviewed-by: Nathan Zimmer <nzim...@sgi.com> Cc: Alex Thorlton <athorl...@sgi.com> Cc: Andrew Banman <aban...@sgi.com> Cc: Andrew Morton <a...@linux-foundation.org> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Russ Anderson <r...@sgi.com> Cc: Thomas Gleixner <t...@linutronix.de> Link: http://lkml.kernel.org/r/20160801184050.250424...@asylum.americas.sgi.com Signed-off-by: Ingo Molnar <mi...@kernel.org> --- arch/x86/platform/uv/bios_uv.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/x86/platform/uv/bios_uv.c b/arch/x86/platform/uv/bios_uv.c index 66b2166..4e9fd13 100644 --- a/arch/x86/platform/uv/bios_uv.c +++ b/arch/x86/platform/uv/bios_uv.c @@ -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; } }
