Messages in this thread | | | From | Dmitry Vyukov <> | Date | Sun, 31 Jan 2021 11:00:12 +0100 | Subject | Re: [PATCH] riscv: virt_addr_valid must check the address belongs to linear mapping |
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On Fri, Jan 29, 2021 at 6:31 PM Alexandre Ghiti <alex@ghiti.fr> wrote: > > virt_addr_valid macro checks that a virtual address is valid, ie that > the address belongs to the linear mapping and that the corresponding > physical page exists. > > Add the missing check that ensures the virtual address belongs to the > linear mapping, otherwise __virt_to_phys, when compiled with > CONFIG_DEBUG_VIRTUAL enabled, raises a WARN that is interpreted as a > kernel bug by syzbot.
Thanks, Alexandre. Much appreciated.
> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> > --- > arch/riscv/include/asm/page.h | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h > index 2d50f76efe48..64a675c5c30a 100644 > --- a/arch/riscv/include/asm/page.h > +++ b/arch/riscv/include/asm/page.h > @@ -135,7 +135,10 @@ extern phys_addr_t __phys_addr_symbol(unsigned long x); > > #endif /* __ASSEMBLY__ */ > > -#define virt_addr_valid(vaddr) (pfn_valid(virt_to_pfn(vaddr))) > +#define virt_addr_valid(vaddr) ({ \ > + unsigned long _addr = (unsigned long)vaddr; \ > + (unsigned long)(_addr) >= PAGE_OFFSET && pfn_valid(virt_to_pfn(_addr)); \ > +}) > > #define VM_DATA_DEFAULT_FLAGS VM_DATA_FLAGS_NON_EXEC > > -- > 2.20.1 >
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