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| author |   Johannes Berg <johannes.berg@intel.com> | 2015-11-27 21:59:41 +0100 |
|---|---|---|
| committer | Johannes Berg <johannes.berg@intel.com> | 2015-12-02 22:27:53 +0100 |
| commit | c1df932c0574c13ab3ce72e969c9647ff3aaad68 (patch) | |
| tree | 837ad522ed41b46dddc5eb88bf7ed26b3bb6b477 /net | |
| parent | mac80211: do not actively scan DFS channels (diff) | |
| download | linux-dev-c1df932c0574c13ab3ce72e969c9647ff3aaad68.tar.xz linux-dev-c1df932c0574c13ab3ce72e969c9647ff3aaad68.zip | |
mac80211: fix off-channel mgmt-tx uninitialized variable usage
In the last change here, I neglected to update the cookie in one code
path: when a mgmt-tx has no real cookie sent to userspace as it doesn't
wait for a response, but is off-channel. The original code used the SKB
pointer as the cookie and always assigned the cookie to the TX SKB in
ieee80211_start_roc_work(), but my change turned this around and made
the code rely on a valid cookie being passed in.
Unfortunately, the off-channel no-wait TX path wasn't assigning one at
all, resulting in an uninitialized stack value being used. This wasn't
handed back to userspace as a cookie (since in the no-wait case there
isn't a cookie), but it was tested for non-zero to distinguish between
mgmt-tx and off-channel.
Fix this by assigning a dummy non-zero cookie unconditionally, and get
rid of a misleading comment and some dead code while at it. I'll clean
up the ACK SKB handling separately later.
Fixes: 3b79af973cf4 ("mac80211: stop using pointers as userspace cookies")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/mac80211/cfg.c | 8 |
1 files changed, 6 insertions, 2 deletions
diff --git a/net/mac80211/cfg.c b/net/mac80211/cfg.c index c2bd1b6a6922..da471eef07bb 100644 --- a/net/mac80211/cfg.c +++ b/net/mac80211/cfg.c @@ -3454,8 +3454,12 @@ static int ieee80211_mgmt_tx(struct wiphy *wiphy, struct wireless_dev *wdev, goto out_unlock; } } else { - /* for cookie below */ - ack_skb = skb; + /* Assign a dummy non-zero cookie, it's not sent to + * userspace in this case but we rely on its value + * internally in the need_offchan case to distinguish + * mgmt-tx from remain-on-channel. + */ + *cookie = 0xffffffff; } if (!need_offchan) { |