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| author | Xue jiufei <xuejiufei@huawei.com> | 2013-07-04 00:01:10 +0200 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-07-04 01:07:25 +0200 |
| commit | 4a184b4ff424e544359f081087723fc36efe603e (patch) | |
| tree | 9d882bd2e436365a0669b5f29f0bb0caeeb108b0 /fs/ocfs2 | |
| parent | ocfs2: adjust switch_case syntax at o2net_state_change() (diff) | |
| download | linux-4a184b4ff424e544359f081087723fc36efe603e.tar.xz linux-4a184b4ff424e544359f081087723fc36efe603e.zip | |
ocfs2: fix NULL pointer dereference when traversing o2hb_all_regions
There may exist NULL pointer dereference in config_item_name() when one
volume (say Volume A) unmounts while another (say Volume B) mounting.
Volume A Volume B
already Mounted.
Unmounting, call
o2hb_heartbeat_group_drop_item()
-> config_item_put(item)
set reg(A)->item.ci_name to NULL
in function config_item_cleanup().
begin mounting, call
o2hb_region_pin() and tranverse all
regions. When reading
reg(A)->item.ci_name, it causes
NULL pointer dereference.
call o2hb_region_release() and
del reg(A) from list.
So we should skip accessing regions that is going to release when
tranverse o2hb_all_regions.
Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Signed-off-by: joyce <xuejiufei@huawei.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Sunil Mushran <sunil.mushran@gmail.com>
Cc: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/ocfs2')
| -rw-r--r-- | fs/ocfs2/cluster/heartbeat.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/ocfs2/cluster/heartbeat.c b/fs/ocfs2/cluster/heartbeat.c index 956d79d1fdde..5c1c864e81cc 100644 --- a/fs/ocfs2/cluster/heartbeat.c +++ b/fs/ocfs2/cluster/heartbeat.c @@ -2389,6 +2389,9 @@ static int o2hb_region_pin(const char *region_uuid) assert_spin_locked(&o2hb_live_lock); list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) { + if (reg->hr_item_dropped) + continue; + uuid = config_item_name(®->hr_item); /* local heartbeat */ @@ -2439,6 +2442,9 @@ static void o2hb_region_unpin(const char *region_uuid) assert_spin_locked(&o2hb_live_lock); list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) { + if (reg->hr_item_dropped) + continue; + uuid = config_item_name(®->hr_item); if (region_uuid) { if (strcmp(region_uuid, uuid)) @@ -2654,6 +2660,9 @@ int o2hb_get_all_regions(char *region_uuids, u8 max_regions) p = region_uuids; list_for_each_entry(reg, &o2hb_all_regions, hr_all_item) { + if (reg->hr_item_dropped) + continue; + mlog(0, "Region: %s\n", config_item_name(®->hr_item)); if (numregs < max_regions) { memcpy(p, config_item_name(®->hr_item), |