On 11/28/17, Andrei Vagin <ava...@virtuozzo.com> wrote: > On Tue, Nov 21, 2017 at 12:27:06AM +0300, Alexey Dobriyan wrote: >> Current code does: >> >> if (sscanf(dentry->d_name.name, "%lx-%lx", start, end) != 2) >> >> However sscanf() is broken garbage. >> >> It silently accepts whitespace between format specifiers >> (did you know that?). >> >> It silently accepts valid strings which result in integer overflow. >> >> Do not use sscanf() for any even remotely reliable parsing code. > > This patch breaks criu, criu has one places where a file name is generated > as map_files/%p-%p
> openat(1048572, "map_files/0x7f9912dd5000-0x7f9912de4000", O_RDWR) = -1 glibc prints null pointer as "(nil)", so %p is broken even if lookup is fixed. > And this code worked before this patch and it doesn't work with this > patch. And you have to know that we never break user-space programs ;) OK :-)