Messages in this thread | | | Date | Thu, 15 Mar 2018 17:03:09 +0900 | From | Sergey Senozhatsky <> | Subject | Re: [PATCH v3] vsprintf: Prevent crash when dereferencing invalid pointers |
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On (03/15/18 16:58), Sergey Senozhatsky wrote: > On (03/14/18 15:09), Petr Mladek wrote: > [..] > > +static const char *check_pointer_access(const void *ptr) > > +{ > > + unsigned char byte; > > + > > + if (!ptr) > > + return "(null)"; > > + > > + if (probe_kernel_read(&byte, ptr, 1)) > ^^^^^ > Why one byte? sizeof(ptr)?
I think there is a shorter version - probe_kernel_address(), which, seems, was designed for this particular kind of stuff.
void *p;
if (probe_kernel_address(ptr, p)) ....
-ss
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