| Message ID | 20190906154303.9303-1-denkenz@gmail.com (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Johannes Berg |
| Headers | show |
| Series | [RFCv3,1/3] nl80211: Fix broken non-split wiphy dumps | expand |
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c index 3e30e18d1d89..ff6200fcd492 100644 --- a/net/wireless/nl80211.c +++ b/net/wireless/nl80211.c @@ -2191,6 +2191,9 @@ static int nl80211_send_wiphy(struct cfg80211_registered_device *rdev, * but break unconditionally so unsplit data stops here. */ state->split_start++; + + if (!state->split) + state->split_start = 0; break; case 9: if (rdev->wiphy.extended_capabilities &&
If a (legacy) client requested a wiphy dump but did not provide the NL80211_ATTR_SPLIT_WIPHY_DUMP attribute, the dump was supposed to be composed of purely non-split NEW_WIPHY messages, with 1 wiphy per message. At least this was the intent after commit: 3713b4e364ef ("nl80211: allow splitting wiphy information in dumps") However, in reality the non-split dumps were broken very shortly after. Perhaps around commit: fe1abafd942f ("nl80211: re-add channel width and extended capa advertising") The reason for the bug is a missing setting of split_start to 0 in the case of a non-split dump. Here is a sample non-split dump performed on kernel 4.19, some parts were cut for brevity: < Request: Get Wiphy (0x01) len 0 [ack,0x300] > Result: New Wiphy (0x03) len 3496 [multi] Wiphy: 0 (0x00000000) Wiphy Name: phy0 Generation: 1 (0x00000001) <snip> > Result: New Wiphy (0x03) len 68 [multi] Wiphy: 0 (0x00000000) Wiphy Name: phy0 Generation: 1 (0x00000001) Extended Capabilities: len 8 Capability: bit 2: Extended channel switching Capability: bit 62: Opmode Notification Extended Capabilities Mask: len 8 04 00 00 00 00 00 00 40 .......@ VHT Capability Mask: len 12 f0 1f 80 33 ff ff 00 00 ff ff 00 00 ...3........ > Result: New Wiphy (0x03) len 28 [multi] Wiphy: 0 (0x00000000) Wiphy Name: phy0 Generation: 1 (0x00000001) > Result: New Wiphy (0x03) len 28 [multi] Wiphy: 0 (0x00000000) Wiphy Name: phy0 Generation: 1 (0x00000001) > Result: New Wiphy (0x03) len 52 [multi] Wiphy: 0 (0x00000000) Wiphy Name: phy0 Generation: 1 (0x00000001) Max CSA Counters: len 1 02 . Scheduled Scan Maximum Requests: len 4 01 00 00 00 .... Extended Features: len 4 02 02 00 04 .... > Result: New Wiphy (0x03) len 36 [multi] Wiphy: 0 (0x00000000) Wiphy Name: phy0 Generation: 1 (0x00000001) Reserved: len 4 00 00 00 00 .... > Complete: Get Wiphy (0x01) len 4 [multi] Status: 0 Signed-off-by: Denis Kenzior <denkenz@gmail.com> --- net/wireless/nl80211.c | 3 +++ 1 file changed, 3 insertions(+)