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| author | NeilBrown <neilb@suse.de> | 2015-06-25 17:01:40 +1000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-08-03 09:29:12 -0700 |
| commit | adeb846a6d8fdc8b9dc19a65393382838cad727f (patch) | |
| tree | 6d727eff7120e76f2ac81684e31d7cb83717e4e1 /drivers/md/md.c | |
| parent | 499b1532e1ee4e3c6ebc1ced5a1d1e75f696262e (diff) | |
| download | lwn-adeb846a6d8fdc8b9dc19a65393382838cad727f.tar.gz lwn-adeb846a6d8fdc8b9dc19a65393382838cad727f.zip | |
md: clear mddev->private when it has been freed.
commit bd6919228d7e1867ae9e24ab27e3e4a366c87d21 upstream.
If ->private is set when ->run is called, it is assumed to be
a 'config' prepared as part of 'reshape'.
So it is important when we free that config, that we also clear ->private.
This is not often a problem as the mddev will normally be discarded
shortly after the config us freed.
However if an 'assemble' races with a final close, the assemble can use
the old mddev which has a stale ->private. This leads to any of
various sorts of crashes.
So clear ->private after calling ->free().
Reported-by: Nate Clark <nate@neworld.us>
Fixes: afa0f557cb15 ("md: rename ->stop to ->free")
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/md/md.c')
| -rw-r--r-- | drivers/md/md.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/md/md.c b/drivers/md/md.c index 4dbed4a67aaf..5b7c914908cd 100644 --- a/drivers/md/md.c +++ b/drivers/md/md.c @@ -5159,6 +5159,7 @@ int md_run(struct mddev *mddev) mddev_detach(mddev); if (mddev->private) pers->free(mddev, mddev->private); + mddev->private = NULL; module_put(pers->owner); bitmap_destroy(mddev); return err; @@ -5294,6 +5295,7 @@ static void md_clean(struct mddev *mddev) mddev->changed = 0; mddev->degraded = 0; mddev->safemode = 0; + mddev->private = NULL; mddev->merge_check_needed = 0; mddev->bitmap_info.offset = 0; mddev->bitmap_info.default_offset = 0; @@ -5366,6 +5368,7 @@ static void __md_stop(struct mddev *mddev) mddev->pers = NULL; spin_unlock(&mddev->lock); pers->free(mddev, mddev->private); + mddev->private = NULL; if (pers->sync_request && mddev->to_remove == NULL) mddev->to_remove = &md_redundancy_group; module_put(pers->owner); |