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| author | Andy Lutomirski <luto@kernel.org> | 2016-07-14 13:22:54 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-07-15 10:26:27 +0200 |
| commit | 46aea3873401836abb7f01200e7946e7d518b359 (patch) | |
| tree | 9e20fb9a4c8a3fbc0446d33bc04547f9d84edf38 /arch/x86/mm | |
| parent | 98f30b1207932b6553ea605c99393d8afca12324 (diff) | |
| download | linux-46aea3873401836abb7f01200e7946e7d518b359.tar.gz | |
x86/mm/64: In vmalloc_fault(), use CR3 instead of current->active_mm
If we get a vmalloc fault while current->active_mm->pgd doesn't match CR3, we'll crash without this change. I've seen this failure mode on heavily instrumented kernels with virtually mapped stacks. Signed-off-by: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.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> Link: http://lkml.kernel.org/r/4650d7674185f165ed8fdf9ac4c5c35c5c179ba8.1468527351.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/mm')
| -rw-r--r-- | arch/x86/mm/fault.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 7d1fa7cd2374..ca44e2e7fd00 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -439,7 +439,7 @@ static noinline int vmalloc_fault(unsigned long address) * happen within a race in page table update. In the later * case just flush: */ - pgd = pgd_offset(current->active_mm, address); + pgd = (pgd_t *)__va(read_cr3()) + pgd_index(address); pgd_ref = pgd_offset_k(address); if (pgd_none(*pgd_ref)) return -1; |