On Tue, Aug 18, 2020 at 08:43:56PM -0700, Elliott Mitchell wrote: > On Wed, Aug 19, 2020 at 04:00:36AM +0200, Marek Marczykowski-G??recki wrote: > > diff --git a/tools/libxl/libxl_utils.c b/tools/libxl/libxl_utils.c > > index f360f5e228..b039143b8a 100644 > > --- a/tools/libxl/libxl_utils.c > > +++ b/tools/libxl/libxl_utils.c > > > > } > > memset(un, 0, sizeof(struct sockaddr_un)); > > un->sun_family = AF_UNIX; > > - strncpy(un->sun_path, path, sizeof(un->sun_path)); > > + strncpy(un->sun_path, path, sizeof(un->sun_path) - 1); > > return 0; > > } > > While the earlier lines are okay, this line introduces an error.
Why exactly? strncpy() copies up to n characters, quoting its manual
page:
If there is no null byte among the first n bytes of src, the string
placed in dest will not be null-terminated
But since the whole struct is zeroed out initially, this should still
result in a null terminated string, as the last byte of that buffer will
not be touched by the strncpy.
--
Best Regards,
Marek Marczykowski-Górecki
Invisible Things Lab
A: Because it messes up the order in which people normally read text.
Q: Why is top-posting such a bad thing?
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