Let's move away from using strncpy and instead favor a less ambiguous
and more robust interface.
For ifp->ndev->name, we expect ifp->ndev->name to be NUL-terminated based
on its use in format strings within core.c:
67 | char *brcmf_ifname(struct brcmf_if *ifp)
68 | {
69 | if (!ifp)
70 | return "<if_null>";
71 |
72 | if (ifp->ndev)
73 | return ifp->ndev->name;
74 |
75 | return "<if_none>";
76 | }
...
288 | static netdev_tx_t brcmf_netdev_start_xmit(struct sk_buff *skb,
289 | struct net_device *ndev) {
...
330 | brcmf_dbg(INFO, "%s: insufficient headroom (%d)\n",
331 | brcmf_ifname(ifp), head_delta);
...
336 | bphy_err(drvr, "%s: failed to expand headroom\n",
337 | brcmf_ifname(ifp));
For di->name, we expect di->name to be NUL-terminated based on its usage
with format strings:
| brcms_dbg_dma(di->core,
| "%s: DMA64 tx doesn't have AE set\n",
| di->name);
Looking at its allocation we can see that it is already zero-allocated
which means NUL-padding is not required:
| di = kzalloc(sizeof(struct dma_info), GFP_ATOMIC);
For wlc->modulecb[i].name, we expect each name in wlc->modulecb to be
NUL-terminated based on their usage with strcmp():
| if (!strcmp(wlc->modulecb[i].name, name) &&
NUL-padding is not required as wlc is zero-allocated in:
brcms_c_attach_malloc() ->
| wlc = kzalloc(sizeof(struct brcms_c_info), GFP_ATOMIC);
For all these cases, a suitable replacement is `strscpy` due to the fact
that it guarantees NUL-termination on the destination buffer without
unnecessarily NUL-padding.
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 2 +-
drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c | 2 +-
drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c | 3 +--
drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c | 4 ++--
4 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
index 2a90bb24ba77..7daa418df877 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
@@ -866,7 +866,7 @@ struct wireless_dev *brcmf_apsta_add_vif(struct wiphy *wiphy, const char *name,
goto fail;
}
- strncpy(ifp->ndev->name, name, sizeof(ifp->ndev->name) - 1);
+ strscpy(ifp->ndev->name, name, sizeof(ifp->ndev->name));
err = brcmf_net_attach(ifp, true);
if (err) {
bphy_err(drvr, "Registering netdevice failed\n");
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
index d4492d02e4ea..6e0c90f4718b 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/p2p.c
@@ -2334,7 +2334,7 @@ struct wireless_dev *brcmf_p2p_add_vif(struct wiphy *wiphy, const char *name,
goto fail;
}
- strncpy(ifp->ndev->name, name, sizeof(ifp->ndev->name) - 1);
+ strscpy(ifp->ndev->name, name, sizeof(ifp->ndev->name));
ifp->ndev->name_assign_type = name_assign_type;
err = brcmf_net_attach(ifp, true);
if (err) {
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c
index b7df576bb84d..3d5c1ef8f7f2 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/dma.c
@@ -584,8 +584,7 @@ struct dma_pub *dma_attach(char *name, struct brcms_c_info *wlc,
rxextheadroom, nrxpost, rxoffset, txregbase, rxregbase);
/* make a private copy of our callers name */
- strncpy(di->name, name, MAXNAMEL);
- di->name[MAXNAMEL - 1] = '\0';
+ strscpy(di->name, name, sizeof(di->name));
di->dmadev = core->dma_dev;
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c
index b3663c5ef382..34460b5815d0 100644
--- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c
@@ -5551,8 +5551,8 @@ int brcms_c_module_register(struct brcms_pub *pub,
/* find an empty entry and just add, no duplication check! */
for (i = 0; i < BRCMS_MAXMODULES; i++) {
if (wlc->modulecb[i].name[0] == '\0') {
- strncpy(wlc->modulecb[i].name, name,
- sizeof(wlc->modulecb[i].name) - 1);
+ strscpy(wlc->modulecb[i].name, name,
+ sizeof(wlc->modulecb[i].name));
wlc->modulecb[i].hdl = hdl;
wlc->modulecb[i].down_fn = d_fn;
return 0;
--
2.42.0.655.g421f12c284-goog
