| Message ID | 20210602181133.3326856-1-keescook@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | net: bonding: Use strscpy() instead of manually-truncated strncpy() | expand |
On Wed, Jun 02, 2021 at 12:46:46PM -0700, Rao Shoaib wrote: > Would it make sense to also replace the other strncpy in the same file. strncpy(ifr.ifr_name, slave_dev->name, IFNAMSIZ); I couldn't tell if this was a non-string, if it needed padding, etc. The one I fixed below appears to be null-terminated? (Though now that I look at it, perhaps it should be using strscpy_pad().) And there are a bunch of other manual truncations in the kernel on ifr_name: $ git grep ifr_name | grep 'IFNAMSIZ.*=.*0' drivers/net/tun.c: ifr.ifr_name[IFNAMSIZ-1] = '\0'; net/core/dev_ioctl.c: ifr->ifr_name[IFNAMSIZ-1] = 0; net/core/dev_ioctl.c: ifr->ifr_name[IFNAMSIZ-1] = 0; net/decnet/dn_dev.c: ifr->ifr_name[IFNAMSIZ-1] = 0; net/ieee802154/socket.c: ifr.ifr_name[IFNAMSIZ-1] = 0; net/ipv4/devinet.c: ifr->ifr_name[IFNAMSIZ - 1] = 0; net/wireless/wext-core.c: iwr.ifr_name[IFNAMSIZ-1] = 0; tools/lib/bpf/xsk.c: ifr.ifr_name[IFNAMSIZ - 1] = '\0'; And given the copy_to_user() that might happen, I think this should absolutely be strscpy_pad(). I will send a v2... -Kees > > Shoaib > > On 6/2/21 11:11 AM, Kees Cook wrote: > > Silence this warning by just using strscpy() directly: > > > > drivers/net/bonding/bond_main.c:4877:3: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation] > > 4877 | strncpy(params->primary, primary, IFNAMSIZ); > > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > Reported-by: kernel test robot <lkp@intel.com> > > Link: https://lore.kernel.org/lkml/202102150705.fdR6obB0-lkp@intel.com > > Signed-off-by: Kees Cook <keescook@chromium.org> > > --- > > drivers/net/bonding/bond_main.c | 6 ++---- > > 1 file changed, 2 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c > > index c5a646d06102..ecfc48f2d0d0 100644 > > --- a/drivers/net/bonding/bond_main.c > > +++ b/drivers/net/bonding/bond_main.c > > @@ -5329,10 +5329,8 @@ static int bond_check_params(struct bond_params *params) > > (struct reciprocal_value) { 0 }; > > } > > - if (primary) { > > - strncpy(params->primary, primary, IFNAMSIZ); > > - params->primary[IFNAMSIZ - 1] = 0; > > - } > > + if (primary) > > + strscpy(params->primary, primary, sizeof(params->primary)); > > memcpy(params->arp_targets, arp_target, sizeof(arp_target));
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index c5a646d06102..ecfc48f2d0d0 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -5329,10 +5329,8 @@ static int bond_check_params(struct bond_params *params) (struct reciprocal_value) { 0 }; } - if (primary) { - strncpy(params->primary, primary, IFNAMSIZ); - params->primary[IFNAMSIZ - 1] = 0; - } + if (primary) + strscpy(params->primary, primary, sizeof(params->primary)); memcpy(params->arp_targets, arp_target, sizeof(arp_target));
Silence this warning by just using strscpy() directly: drivers/net/bonding/bond_main.c:4877:3: warning: 'strncpy' specified bound 16 equals destination size [-Wstringop-truncation] 4877 | strncpy(params->primary, primary, IFNAMSIZ); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Reported-by: kernel test robot <lkp@intel.com> Link: https://lore.kernel.org/lkml/202102150705.fdR6obB0-lkp@intel.com Signed-off-by: Kees Cook <keescook@chromium.org> --- drivers/net/bonding/bond_main.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-)