[PATCH] wifi: cfg80211: allow zero HE OBSS PD offsets

[PATCH] wifi: cfg80211: allow zero HE OBSS PD offsets

[github]

From: Dominic White <github@singe.za.net>

IEEE Std 802.11 permits the OBSS PD offset fields in the Spatial Reuse
Parameter Set element to have a value of zero. (IEEE Std 802.11-2024,
26.10.2.4)

The standard specifies the offsets as unsigned values added to -82 dBm,
with field presence signalled independently. The valid offset range is
therefore 0..20.

nl80211 currently rejects zero for all three HE OBSS PD offset
attributes during nested netlink policy validation, before the values
reach cfg80211 or the driver. Allow zero while retaining the upper bound
and the existing minimum/maximum relationship validation.

Fixes: 796e90f42b7e ("cfg80211: add support for parsing OBBS_PD attributes")
Signed-off-by: Dominic White <github@singe.za.net>
---
 net/wireless/nl80211.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index 44f2bad08..57251cff9 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -529,11 +529,11 @@ nl80211_pmsr_attr_policy[NL80211_PMSR_ATTR_MAX + 1] = {
 static const struct nla_policy
 he_obss_pd_policy[NL80211_HE_OBSS_PD_ATTR_MAX + 1] = {
 	[NL80211_HE_OBSS_PD_ATTR_MIN_OFFSET] =
-		NLA_POLICY_RANGE(NLA_U8, 1, 20),
+		NLA_POLICY_RANGE(NLA_U8, 0, 20),
 	[NL80211_HE_OBSS_PD_ATTR_MAX_OFFSET] =
-		NLA_POLICY_RANGE(NLA_U8, 1, 20),
+		NLA_POLICY_RANGE(NLA_U8, 0, 20),
 	[NL80211_HE_OBSS_PD_ATTR_NON_SRG_MAX_OFFSET] =
-		NLA_POLICY_RANGE(NLA_U8, 1, 20),
+		NLA_POLICY_RANGE(NLA_U8, 0, 20),
 	[NL80211_HE_OBSS_PD_ATTR_BSS_COLOR_BITMAP] =
 		NLA_POLICY_EXACT_LEN(8),
 	[NL80211_HE_OBSS_PD_ATTR_PARTIAL_BSSID_BITMAP] =

base-commit: 89a312991dc6e638a36adc43ccb91dbc25504c04
-- 
2.50.1 (Apple Git-155)

Re: [PATCH] wifi: cfg80211: allow zero HE OBSS PD offsets

[Johannes Berg]

On Thu, 2026-09-03 at 10:18 +0200, github@singe.za.net wrote:
> From: Dominic White <github@singe.za.net>
> 
> IEEE Std 802.11 permits the OBSS PD offset fields in the Spatial Reuse
> Parameter Set element to have a value of zero. (IEEE Std 802.11-2024,
> 26.10.2.4)
> 
> The standard specifies the offsets as unsigned values added to -82 dBm,
> with field presence signalled independently. The valid offset range is
> therefore 0..20.

However, leaving the attribute unset automatically results in zero, so
functionally it's not really needed.

johannes