Messages in this thread | | | Date | Wed, 24 Sep 2014 18:41:42 +0300 | From | Dan Carpenter <> | Subject | Re: [PATCH] lib: string.c: Added a funktion function strzcpy |
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On Wed, Sep 24, 2014 at 07:35:55AM -0700, Andi Kleen wrote: > On Wed, Sep 24, 2014 at 10:52:06AM +0300, Dan Carpenter wrote: > > On Tue, Sep 23, 2014 at 06:17:53PM -0700, Andi Kleen wrote: > > > On Wed, Sep 24, 2014 at 12:13:36AM +0200, Rickard Strandqvist wrote: > > > > Added a function strzcpy which works the same as strncpy, > > > > but guaranteed to produce the trailing null character. > > > > > > Do we really need the bizarre strncpy padding semantics for anything? > > > Why not just use strlcpy? > > > > We do need the padding in many places to prevent information leaks. > > Like where? >
You're asking what would break if we switched every strncpy() to strlcpy() but it's not an easy question to answer.
I've looked a lot at information leaks, but strings are still a blind spot for my Smatch. My check only looks at normal variables, arrays. Eventually I hope to fix this, of course.
I did a git search and Rickard has added some examples, but there were definitely other places that rely strncpy() padding before.
regards, dan carpenter
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