The patch titled
Subject: ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3
has been removed from the -mm tree. Its filename was
ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3.patch
This patch was dropped because it was folded into ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages.patch
------------------------------------------------------
From: jiangyiwen <jiangyiwen@xxxxxxxxxx>
Subject: ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3
The following case will lead to a lockres is freed but is still in use.
cat /sys/kernel/debug/o2dlm/locking_state dlm_thread
lockres_seq_start
-> lock dlm->track_lock
-> get resA
resA->refs decrease to 0,
call dlm_lockres_release,
and wait for "cat" unlock.
Although resA->refs is already set to 0,
increase resA->refs, and then unlock
lock dlm->track_lock
-> list_del_init()
-> unlock
-> free resA
In such a race case, invalid address access may occurs.
So we should delete list res->tracking before resA->refs decrease to 0.
Signed-off-by: Yiwen Jiang <jiangyiwen@xxxxxxxxxx>
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/dlm/dlmmaster.c | 13 ++++++++++++-
1 file changed, 12 insertions(+), 1 deletion(-)
diff -puN fs/ocfs2/dlm/dlmmaster.c~ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3 fs/ocfs2/dlm/dlmmaster.c
--- a/fs/ocfs2/dlm/dlmmaster.c~ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages-v3
+++ a/fs/ocfs2/dlm/dlmmaster.c
@@ -772,8 +772,19 @@ lookup:
dlm_lockres_grab_inflight_ref(dlm, tmpres);
spin_unlock(&tmpres->spinlock);
- if (res)
+ if (res) {
+ spin_lock(&dlm->track_lock);
+ if (!list_empty(&res->tracking))
+ list_del_init(&res->tracking);
+ else {
+ mlog(ML_ERROR, "Resource %.*s not "
+ "on the Tracking list\n",
+ res->lockname.len,
+ res->lockname.name);
+ }
+ spin_unlock(&dlm->track_lock);
dlm_lockres_put(res);
+ }
res = tmpres;
goto leave;
}
_
Patches currently in -mm which might be from jiangyiwen@xxxxxxxxxx are
ocfs2-do-not-use-ocfs2_zero_extend-during-direct-io.patch
ocfs2-use-actual-name-length-when-find-entry-in-ocfs2_orphan_del.patch
ocfs2-fix-a-tiny-case-that-inode-can-not-removed.patch
ocfs2-avoid-access-invalid-address-when-read-o2dlm-debug-messages.patch
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