Messages in this thread | | | Date | Mon, 12 Mar 2012 07:31:08 +0100 | From | Willy Tarreau <> | Subject | Re: [ 08/12] mac80211: zero initialize count field in ieee80211_tx_rate |
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On Mon, Mar 12, 2012 at 01:57:52AM +0000, Ben Hutchings wrote: > On Mon, 2012-03-12 at 01:20 +0100, Willy Tarreau wrote: > > 2.6.32-longterm review patch. If anyone has any objections, please let me know. > > > > ------------------ > > > > From: Mohammed Shafi Shajakhan <mohammed@qca.qualcomm.com> > > > > commit 8617b093d0031837a7be9b32bc674580cfb5f6b5 upstream. > > > > rate control algorithms concludes the rate as invalid > > with rate[i].idx < -1 , while they do also check for rate[i].count is > > non-zero. it would be safer to zero initialize the 'count' field. > > recently we had a ath9k rate control crash where the ath9k rate control > > in ath_tx_status assumed to check only for rate[i].count being non-zero > > in one instance and ended up in using invalid rate index for > > 'connection monitoring NULL func frames' which eventually lead to the crash. > > thanks to Pavel Roskin for fixing it and finding the root cause. > > https://bugzilla.redhat.com/show_bug.cgi?id=768639 > > In 2.6.32, ath_tx_status() checks that rates[i].idx >= 0, so it properly > ignores these dummy entries. Further, there is code further down the > rate_control_get_rate() function that sets .idx only and appears to > depend on the initialisation of .count = 1. > > So I'm pretty sure this patch is wrong for 2.6.32; it could be > backported but I don't think the change is necessary anyway.
Dropping it then, thanks Ben !
Willy
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