Re: [PATCH net-next v3] tipc: replace deprecated strcpy with strscpy in tipc_bearer_get_name()

[David Laight <david.laight.linux@gmail.com>]

On Mon, 17 Aug 2026 07:53:53 +0000
Tung Quang Nguyen <tung.quang.nguyen@est.tech> wrote:

> >Subject: Re: [PATCH net-next v3] tipc: replace deprecated strcpy with strscpy in
> >tipc_bearer_get_name()
> >  
> >> net tree:
> >> https://git.kernel.org/pub/scm/linux/kernel/git/davem/net.git
> >> net-next tree:
> >> https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git  
> >
> >Thank you. I tried the correct net-next tree. The same patch applied
> >successfully here also as shown below.
> >
> ><path of the linux tree>/net-next$ ls
> >arch   certs    CREDITS  Documentation  fs       init      ipc     Kconfig  lib
> >MAINTAINERS  mm   README  samples  security  tools  virt
> >block  COPYING  crypto   drivers        include  io_uring  Kbuild  kernel   LICENSES
> >Makefile     net  rust    scripts  sound     usr
> ><path of the linux tree>/net-next$ git remote -v
> >origin	https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
> >(fetch)
> >origin	https://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git
> >(push)
> ><path of the linux tree>/net-next$ git am ../../patches/v3-0001-tipc-replace-
> >deprecated-strcpy-with-strscpy-in-ti.patch
> >Applying: tipc: replace deprecated strcpy with strscpy in
> >tipc_bearer_get_name() <path of the linux tree>/net-next$ git branch
> >* main
> ><path of the linux tree>/net-next$
> >
> >Am I missing something?  
> 
> I see that your patch was applied again successfully after failure.
> There is one feedback from AI review that I see valid:
> [...]
> > @@ -209,7 +209,7 @@ int tipc_bearer_get_name(struct net *net, char *name, u32 bearer_id)
> >  	if (!b)
> >  		return -EINVAL;
> >  
> > -	strcpy(name, b->name);
> > +	strscpy(name, b->name, TIPC_MAX_BEARER_NAME);  
> This isn't a bug, but the destination capacity is now hard-coded in the
> body while the interface says nothing about it.  The declaration in
> net/tipc/bearer.h is still:
> 	int tipc_bearer_get_name(struct net *net, char *name, u32 bearer_id);
> and the comment directly above the implementation only says:
> 	 *     @name: a pointer to the buffer where the name will be stored.
> Should the TIPC_MAX_BEARER_NAME requirement be spelled out in the comment
> or in the prototype, so that the interface and the body agree?
> In the current tree there is no behavioural change: the only caller is
> __tipc_nl_add_monitor() in net/tipc/monitor.c, which declares
> char bearer_name[TIPC_MAX_BEARER_NAME], and the source is
> char name[TIPC_MAX_BEARER_NAME] in struct tipc_bearer, so the copy can
> neither truncate nor overflow.
> The strscpy() return value is also discarded, so a future caller passing a
> smaller buffer would get a silently truncated name plus a return of 0.
> Would passing a size_t len from the caller (sizeof(bearer_name)) and
> forwarding strscpy()'s -E2BIG through the existing int return be preferable
> to a hard-coded bound?
> [...]
> 
> Please update your patch and send the new version after Aug 31st. (Because net-next is closed now)
> 

One 'solution' to the non-problem is to embed the array in a struct.
Although (IIRC) this is a uapi constant so that may not be completely
possible.

Otherwise I'd ignore the AI review.

	David