On Tue, 24 Sep 2024, Mirsad Todorovac wrote: > GCC 13.2.0 reported with W=1 build option the following warning: See https://lore.kernel.org/all/20240814093853.48657-1-kunwu.chan@xxxxxxxxx/ I don't think anyone really cares about this one. NeilBrown > > net/sunrpc/clnt.c: In function ‘rpc_create’: > net/sunrpc/clnt.c:582:75: warning: ‘%s’ directive output may be truncated writing up to 107 bytes into \ > a region of size 48 [-Wformat-truncation=] > 582 | snprintf(servername, sizeof(servername), "%s", > | ^~ > net/sunrpc/clnt.c:582:33: note: ‘snprintf’ output between 1 and 108 bytes into a destination of size 48 > 582 | snprintf(servername, sizeof(servername), "%s", > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > 583 | sun->sun_path); > | ~~~~~~~~~~~~~~ > > 548 }; > → 549 char servername[48]; > 550 struct rpc_clnt *clnt; > 551 int i; > 552 > 553 if (args->bc_xprt) { > 554 WARN_ON_ONCE(!(args->protocol & XPRT_TRANSPORT_BC)); > 555 xprt = args->bc_xprt->xpt_bc_xprt; > 556 if (xprt) { > 557 xprt_get(xprt); > 558 return rpc_create_xprt(args, xprt); > 559 } > 560 } > 561 > 562 if (args->flags & RPC_CLNT_CREATE_INFINITE_SLOTS) > 563 xprtargs.flags |= XPRT_CREATE_INFINITE_SLOTS; > 564 if (args->flags & RPC_CLNT_CREATE_NO_IDLE_TIMEOUT) > 565 xprtargs.flags |= XPRT_CREATE_NO_IDLE_TIMEOUT; > 566 /* > 567 * If the caller chooses not to specify a hostname, whip > 568 * up a string representation of the passed-in address. > 569 */ > 570 if (xprtargs.servername == NULL) { > 571 struct sockaddr_un *sun = > 572 (struct sockaddr_un *)args->address; > 573 struct sockaddr_in *sin = > 574 (struct sockaddr_in *)args->address; > 575 struct sockaddr_in6 *sin6 = > 576 (struct sockaddr_in6 *)args->address; > 577 > 578 servername[0] = '\0'; > 579 switch (args->address->sa_family) { > → 580 case AF_LOCAL: > → 581 if (sun->sun_path[0]) > → 582 snprintf(servername, sizeof(servername), "%s", > → 583 sun->sun_path); > → 584 else > → 585 snprintf(servername, sizeof(servername), "@%s", > → 586 sun->sun_path+1); > → 587 break; > 588 case AF_INET: > 589 snprintf(servername, sizeof(servername), "%pI4", > 590 &sin->sin_addr.s_addr); > 591 break; > 592 case AF_INET6: > 593 snprintf(servername, sizeof(servername), "%pI6", > 594 &sin6->sin6_addr); > 595 break; > 596 default: > 597 /* caller wants default server name, but > 598 * address family isn't recognized. */ > 599 return ERR_PTR(-EINVAL); > 600 } > 601 xprtargs.servername = servername; > 602 } > 603 > 604 xprt = xprt_create_transport(&xprtargs); > 605 if (IS_ERR(xprt)) > 606 return (struct rpc_clnt *)xprt; > > After the address family AF_LOCAL was added in the commit 176e21ee2ec89, the old hard-coded > size for servername of char servername[48] no longer fits. The maximum AF_UNIX address size > has now grown to UNIX_PATH_MAX defined as 108 in "include/uapi/linux/un.h" . > > The lines 580-587 were added later, addressing the leading zero byte '\0', but did not fix > the hard-coded servername limit. > > The AF_UNIX address was truncated to 47 bytes + terminating null byte. This patch will fix the > servername in AF_UNIX family to the maximum permitted by the system: > > 548 }; > → 549 char servername[UNIX_PATH_MAX]; > 550 struct rpc_clnt *clnt; > > Fixes: 4388ce05fa38b ("SUNRPC: support abstract unix socket addresses") > Fixes: 510deb0d7035d ("SUNRPC: rpc_create() default hostname should support AF_INET6 addresses") > Fixes: 176e21ee2ec89 ("SUNRPC: Support for RPC over AF_LOCAL transports") > Cc: Neil Brown <neilb@xxxxxxx> > Cc: Chuck Lever <chuck.lever@xxxxxxxxxx> > Cc: Trond Myklebust <trondmy@xxxxxxxxxx> > Cc: Anna Schumaker <anna@xxxxxxxxxx> > Cc: Jeff Layton <jlayton@xxxxxxxxxx> > Cc: Olga Kornievskaia <okorniev@xxxxxxxxxx> > Cc: Dai Ngo <Dai.Ngo@xxxxxxxxxx> > Cc: Tom Talpey <tom@xxxxxxxxxx> > Cc: "David S. Miller" <davem@xxxxxxxxxxxxx> > Cc: Eric Dumazet <edumazet@xxxxxxxxxx> > Cc: Jakub Kicinski <kuba@xxxxxxxxxx> > Cc: Paolo Abeni <pabeni@xxxxxxxxxx> > Cc: linux-nfs@xxxxxxxxxxxxxxx > Cc: netdev@xxxxxxxxxxxxxxx > Cc: linux-kernel@xxxxxxxxxxxxxxx > Signed-off-by: Mirsad Todorovac <mtodorovac69@xxxxxxxxx> > --- > v1: > initial version. > > net/sunrpc/clnt.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c > index 09f29a95f2bc..67099719893e 100644 > --- a/net/sunrpc/clnt.c > +++ b/net/sunrpc/clnt.c > @@ -546,7 +546,7 @@ struct rpc_clnt *rpc_create(struct rpc_create_args *args) > .connect_timeout = args->connect_timeout, > .reconnect_timeout = args->reconnect_timeout, > }; > - char servername[48]; > + char servername[UNIX_PATH_MAX]; > struct rpc_clnt *clnt; > int i; > > -- > 2.43.0 > >
