Messages in this thread | | | From | Linus Torvalds <> | Date | Mon, 13 Sep 2021 10:05:32 -0700 | Subject | Re: [PATCH] x86/uaccess: Fix 32-bit __get_user_asm_u64() when CC_HAS_ASM_GOTO_OUTPUT=y |
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On Mon, Sep 13, 2021 at 9:36 AM Will Deacon <will@kernel.org> wrote: > > Use the existing '__gu_ptr' source pointer to unsigned int for 32-bit > __get_user_asm_u64() instead of the original pointer.
Heh. And by "existing" you mean "the one that exists _purely_ for this exact reason and that wasn't used" ;)
What a silly bug. And it's existed for a year, which I think shows just how little 32-bit x86 is used these days (*).
Linus
(*) but also probably how few 64-bit user accesses we do - the fact that the bug was actually found by the "copy_from_kernel_nofault" code that just shares the infrastructure on x86 rather than any user access code is kind of interesting.
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