diff options
| author | Thomas Pedersen <thomas@eero.com> | 2019-05-25 07:16:24 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-21 10:05:51 +0300 |
| commit | 606b65ebed2df8b4940bb69b9c36b0e99186b238 (patch) | |
| tree | b0d9b1f4e2fe8084b5160c15159da5edb008cb24 /net/mac80211/mesh.c | |
| parent | 04c3ad7b1a7ae3a66733ec93ce1a3272b3c3e5f2 (diff) | |
| download | linux-606b65ebed2df8b4940bb69b9c36b0e99186b238.tar.xz | |
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>
Diffstat (limited to 'net/mac80211/mesh.c')
| -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 b2a27263d6ff..7f902e69530f 100644 --- a/net/mac80211/mesh.c +++ b/net/mac80211/mesh.c @@ -1135,7 +1135,8 @@ 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); @@ -1157,6 +1158,8 @@ 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) |