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authorAvraham Stern <avraham.stern@intel.com>2021-06-18 13:41:31 +0300
committerJohannes Berg <johannes.berg@intel.com>2021-06-18 13:25:24 +0200
commit0288e5e16a2e18f0b7e61a2b70d9037fc6e4abeb (patch)
treec41e742dd0398226a2e9a870caf084a615a3bf9b
parentb5642479b0f7168fe16d156913533fe65ab4f8d5 (diff)
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: 9bb7e0f24e7e ("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>
-rw-r--r--net/wireless/pmsr.c16
1 files changed, 14 insertions, 2 deletions
diff --git a/net/wireless/pmsr.c b/net/wireless/pmsr.c
index 6bdd96408022..d245968b74cb 100644
--- a/net/wireless/pmsr.c
+++ b/net/wireless/pmsr.c
@@ -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 @@ free_msg:
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);