diff options
| author | Thomas Pedersen <thomas@eero.com> | 2019-05-24 21:16:24 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-14 08:11:06 +0200 |
| commit | acc42e5c23228d12ea423a9568293eaf9e0d90a3 (patch) | |
| tree | 0308e05b3d6c8ad6597cc746260c0603cdf73827 | |
| parent | e3868c1a462f2bc41c0f1e584ca12a850fd2ebb9 (diff) | |
mac80211: mesh: fix RCU warning
[ Upstream commit 551842446ed695641a00782cd118cbb064a416a1 ]
ifmsh->csa is an RCU-protected pointer. The writer context
in ieee80211_mesh_finish_csa() is already mutually
exclusive with wdev->sdata.mtx, but the RCU checker did
not know this. Use rcu_dereference_protected() to avoid a
warning.
fixes the following warning:
[ 12.519089] =============================
[ 12.520042] WARNING: suspicious RCU usage
[ 12.520652] 5.1.0-rc7-wt+ #16 Tainted: G W
[ 12.521409] -----------------------------
[ 12.521972] net/mac80211/mesh.c:1223 suspicious rcu_dereference_check() usage!
[ 12.522928] other info that might help us debug this:
[ 12.523984] rcu_scheduler_active = 2, debug_locks = 1
[ 12.524855] 5 locks held by kworker/u8:2/152:
[ 12.525438] #0: 00000000057be08c ((wq_completion)phy0){+.+.}, at: process_one_work+0x1a2/0x620
[ 12.526607] #1: 0000000059c6b07a ((work_completion)(&sdata->csa_finalize_work)){+.+.}, at: process_one_work+0x1a2/0x620
[ 12.528001] #2: 00000000f184ba7d (&wdev->mtx){+.+.}, at: ieee80211_csa_finalize_work+0x2f/0x90
[ 12.529116] #3: 00000000831a1f54 (&local->mtx){+.+.}, at: ieee80211_csa_finalize_work+0x47/0x90
[ 12.530233] #4: 00000000fd06f988 (&local->chanctx_mtx){+.+.}, at: ieee80211_csa_finalize_work+0x51/0x90
Signed-off-by: Thomas Pedersen <thomas@eero.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/mac80211/mesh.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c index d51da26e9c18..0f9446ab7e4f 100644 --- a/net/mac80211/mesh.c +++ b/net/mac80211/mesh.c @@ -1212,7 +1212,8 @@ int ieee80211_mesh_finish_csa(struct ieee80211_sub_if_data *sdata) ifmsh->chsw_ttl = 0; /* Remove the CSA and MCSP elements from the beacon */ - tmp_csa_settings = rcu_dereference(ifmsh->csa); + tmp_csa_settings = rcu_dereference_protected(ifmsh->csa, + lockdep_is_held(&sdata->wdev.mtx)); RCU_INIT_POINTER(ifmsh->csa, NULL); if (tmp_csa_settings) kfree_rcu(tmp_csa_settings, rcu_head); @@ -1234,6 +1235,8 @@ int ieee80211_mesh_csa_beacon(struct ieee80211_sub_if_data *sdata, struct mesh_csa_settings *tmp_csa_settings; int ret = 0; + lockdep_assert_held(&sdata->wdev.mtx); + tmp_csa_settings = kmalloc(sizeof(*tmp_csa_settings), GFP_ATOMIC); if (!tmp_csa_settings) |