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cfg80211: avoid double free of PMSR request 

If cfg80211_pmsr_process_abort() moves all the PMSR requests that
need to be freed into a local list before aborting and freeing them.
As a result, it is possible that cfg80211_pmsr_complete() will run in
parallel and free the same PMSR request.

Fix it by freeing the request in cfg80211_pmsr_complete() only if it
is still in the original pmsr list.

Cc: stable@vger.kernel.org
Fixes: 9bb7e0f24e ("cfg80211: add peer measurement with FTM initiator API")
Signed-off-by: Avraham Stern <avraham.stern@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20210618133832.1fbef57e269a.I00294bebdb0680b892f8d1d5c871fd9dbe785a5e@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
This commit is contained in:
Avraham Stern 2021-06-18 13:41:31 +03:00 committed by Johannes Berg
parent b5642479b0
commit 0288e5e16a
1 changed files with 14 additions and 2 deletions
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16
net/wireless/pmsr.c
View File

@ -334,6 +334,7 @@ void cfg80211_pmsr_complete(struct wireless_dev *wdev,
gfp_t gfp)
{
struct cfg80211_registered_device *rdev = wiphy_to_rdev(wdev->wiphy);
struct cfg80211_pmsr_request *tmp, *prev, *to_free = NULL;
struct sk_buff *msg;
void *hdr;
@ -364,9 +365,20 @@ void cfg80211_pmsr_complete(struct wireless_dev *wdev,
nlmsg_free(msg);
free_request:
spin_lock_bh(&wdev->pmsr_lock);
list_del(&req->list);
/*
* cfg80211_pmsr_process_abort() may have already moved this request
* to the free list, and will free it later. In this case, don't free
* it here.
*/
list_for_each_entry_safe(tmp, prev, &wdev->pmsr_list, list) {
if (tmp == req) {
list_del(&req->list);
to_free = req;
break;
}
}
spin_unlock_bh(&wdev->pmsr_lock);
kfree(req);
kfree(to_free);
}
EXPORT_SYMBOL_GPL(cfg80211_pmsr_complete);