diff options
| author | Stefan Sperling <stsp@cvs.openbsd.org> | 2017-07-23 13:51:12 +0000 |
|---|---|---|
| committer | Stefan Sperling <stsp@cvs.openbsd.org> | 2017-07-23 13:51:12 +0000 |
| commit | 9e923a08f464c558a9d9404a71304e68fd9a42c9 (patch) | |
| tree | 08d6c7cdf82766ed254616a6a449a362effee121 /sys | |
| parent | 8887a76a351d1af00b4a6cb2ca81d34dfadde2fd (diff) | |
Prevent a possible "MAC context already removed" panic in iwm_auth().
This panic happens if iwm_newstate_task() sleeps and wakes up after iwm_stop().
The error path of iwm_newstate_task() attempts to reset driver flags and
firmware state, which should not be done if iwm_stop() has already done so.
A more comprehensive fix for such races is being worked on but not ready yet.
For now, check the generation counter in the error path of iwm_auth() and
only clean up state if that counter hasn't changed.
Problem reported and workaround tested by giovanni@
Diffstat (limited to 'sys')
| -rw-r--r-- | sys/dev/pci/if_iwm.c | 16 |
1 files changed, 10 insertions, 6 deletions
diff --git a/sys/dev/pci/if_iwm.c b/sys/dev/pci/if_iwm.c index 88cbcd7498b..7dc3a4564c0 100644 --- a/sys/dev/pci/if_iwm.c +++ b/sys/dev/pci/if_iwm.c @@ -1,4 +1,4 @@ -/* $OpenBSD: if_iwm.c,v 1.203 2017/07/22 16:48:58 stsp Exp $ */ +/* $OpenBSD: if_iwm.c,v 1.204 2017/07/23 13:51:11 stsp Exp $ */ /* * Copyright (c) 2014, 2016 genua gmbh <info@genua.de> @@ -5375,7 +5375,7 @@ iwm_auth(struct iwm_softc *sc) struct ieee80211com *ic = &sc->sc_ic; struct iwm_node *in = (void *)ic->ic_bss; uint32_t duration; - int err; + int generation = sc->sc_generation, err; splassert(IPL_NET); @@ -5427,11 +5427,15 @@ iwm_auth(struct iwm_softc *sc) return 0; rm_binding: - iwm_binding_cmd(sc, in, IWM_FW_CTXT_ACTION_REMOVE); - sc->sc_flags &= ~IWM_FLAG_BINDING_ACTIVE; + if (generation == sc->sc_generation) { + iwm_binding_cmd(sc, in, IWM_FW_CTXT_ACTION_REMOVE); + sc->sc_flags &= ~IWM_FLAG_BINDING_ACTIVE; + } rm_mac_ctxt: - iwm_mac_ctxt_cmd(sc, in, IWM_FW_CTXT_ACTION_REMOVE, 0); - sc->sc_flags &= ~IWM_FLAG_MAC_ACTIVE; + if (generation == sc->sc_generation) { + iwm_mac_ctxt_cmd(sc, in, IWM_FW_CTXT_ACTION_REMOVE, 0); + sc->sc_flags &= ~IWM_FLAG_MAC_ACTIVE; + } return err; } |