| Message ID | 20240227080613.34001-1-duoming@zju.edu.cn |
|---|---|
| State | New |
| Headers | show |
| Series | wifi: brcm80211: handle pmk_op allocation failure | expand |
On 2/27/2024 9:06 AM, Duoming Zhou wrote: > The kzalloc() in brcmf_pmksa_v3_op() will return null if the > physical memory has run out. As a result, if we dereference > the null value, the null pointer dereference bug will happen. > > Return -ENOMEM from brcmf_pmksa_v3_op() if kzalloc() fails > for pmk_op. NAK (see below) Also this issue was reported earlier by Joe Perches. Not sure if he wants to be mentioned as such. > Fixes: a96202acaea4 ("wifi: brcmfmac: cfg80211: Add support for PMKID_V3 operations") > Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> > --- > drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c > index 28d6a30cc01..3b420b33188 100644 > --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c > +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c > @@ -4322,6 +4322,10 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa, > int ret; > > pmk_op = kzalloc(sizeof(*pmk_op), GFP_KERNEL); > + if (!pmk_op) { > + ret = -ENOMEM; > + goto out; > + } There is really no need to introduce a new label for this. Although you can kfree() a NULL pointer there is no need to do so when you know already it is NULL. Just return -ENOMEM and be done with it. Regards, Arend > pmk_op->version = cpu_to_le16(BRCMF_PMKSA_VER_3); > > if (!pmksa) { > @@ -4340,6 +4344,7 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa, > pmk_op->length = cpu_to_le16(length); > > ret = brcmf_fil_iovar_data_set(ifp, "pmkid_info", pmk_op, sizeof(*pmk_op)); > +out: > kfree(pmk_op); > return ret; > }
On 2/27/2024 12:42 PM, Joe Perches wrote: > On Tue, 2024-02-27 at 12:21 +0100, Arend van Spriel wrote: >> On 2/27/2024 9:06 AM, Duoming Zhou wrote: >>> The kzalloc() in brcmf_pmksa_v3_op() will return null if the >>> physical memory has run out. As a result, if we dereference >>> the null value, the null pointer dereference bug will happen. >>> >>> Return -ENOMEM from brcmf_pmksa_v3_op() if kzalloc() fails >>> for pmk_op. >> >> NAK (see below) >> >> Also this issue was reported earlier by Joe Perches. Not sure if he >> wants to be mentioned as such. > > I think it's unimportant to be mentioned. > > I think it's more important that the code be researched > that the simple return of -ENOMEM the appropriate fix > and is handled by all possible callers of the function. Right. That is what I did after which I replied on Feb 18 to your email. https://lore.kernel.org/all/3e1f11b3-a689-4c8e-bfda-b43649db7106@broadcom.com/ Regards, Arend >> >>> Fixes: a96202acaea4 ("wifi: brcmfmac: cfg80211: Add support for PMKID_V3 operations") >>> Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> >>> --- >>> drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++ >>> 1 file changed, 5 insertions(+) >>> >>> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.cq b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c >>> index 28d6a30cc01..3b420b33188 100644 >>> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c >>> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c >>> @@ -4322,6 +4322,10 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa, >>> int ret; >>> >>> pmk_op = kzalloc(sizeof(*pmk_op), GFP_KERNEL); >>> + if (!pmk_op) { >>> + ret = -ENOMEM; >>> + goto out; >>> + } >> >> There is really no need to introduce a new label for this. Although you >> can kfree() a NULL pointer there is no need to do so when you know >> already it is NULL. Just return -ENOMEM and be done with it. >> >> Regards, >> Arend >> >>> pmk_op->version = cpu_to_le16(BRCMF_PMKSA_VER_3); >>> >>> if (!pmksa) { >>> @@ -4340,6 +4344,7 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa, >>> pmk_op->length = cpu_to_le16(length); >>> >>> ret = brcmf_fil_iovar_data_set(ifp, "pmkid_info", pmk_op, sizeof(*pmk_op)); >>> +out: >>> kfree(pmk_op); >>> return ret; >>> } >
diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c index 28d6a30cc01..3b420b33188 100644 --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c @@ -4322,6 +4322,10 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa, int ret; pmk_op = kzalloc(sizeof(*pmk_op), GFP_KERNEL); + if (!pmk_op) { + ret = -ENOMEM; + goto out; + } pmk_op->version = cpu_to_le16(BRCMF_PMKSA_VER_3); if (!pmksa) { @@ -4340,6 +4344,7 @@ brcmf_pmksa_v3_op(struct brcmf_if *ifp, struct cfg80211_pmksa *pmksa, pmk_op->length = cpu_to_le16(length); ret = brcmf_fil_iovar_data_set(ifp, "pmkid_info", pmk_op, sizeof(*pmk_op)); +out: kfree(pmk_op); return ret; }
The kzalloc() in brcmf_pmksa_v3_op() will return null if the physical memory has run out. As a result, if we dereference the null value, the null pointer dereference bug will happen. Return -ENOMEM from brcmf_pmksa_v3_op() if kzalloc() fails for pmk_op. Fixes: a96202acaea4 ("wifi: brcmfmac: cfg80211: Add support for PMKID_V3 operations") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> --- drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c | 5 +++++ 1 file changed, 5 insertions(+)