| Message ID | 20231017-strncpy-drivers-net-wireless-broadcom-brcm80211-brcmfmac-cfg80211-c-v3-1-af780d74ae38@google.com |
|---|---|
| State | New |
| Headers | show |
| Series | wifi: brcm80211: replace deprecated strncpy | expand |
On Tue, Oct 17, 2023 at 08:11:28PM +0000, Justin Stitt wrote: > 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@google.com> Good; this looks like standard direct replacements. Reviewed-by: Kees Cook <keescook@chromium.org>
Justin Stitt <justinstitt@google.com> wrote: > 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@google.com> > Reviewed-by: Kees Cook <keescook@chromium.org> 2 patches applied to wireless-next.git, thanks. 9d0d0a207040 wifi: brcm80211: replace deprecated strncpy with strscpy a614f9579705 wifi: brcmsmac: replace deprecated strncpy with memcpy
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;
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@google.com> --- 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(-)