[PATCH 3.16 08/99] dlm: memory leaks on error path in dlm_user_request()

From: Ben Hutchings
Date: Tue Apr 02 2019 - 09:46:25 EST


3.16.65-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: Vasily Averin <vvs@xxxxxxxxxxxxx>

commit d47b41aceeadc6b58abc9c7c6485bef7cfb75636 upstream.

According to comment in dlm_user_request() ua should be freed
in dlm_free_lkb() after successful attach to lkb.

However ua is attached to lkb not in set_lock_args() but later,
inside request_lock().

Fixes 597d0cae0f99 ("[DLM] dlm: user locks")

Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx>
Signed-off-by: David Teigland <teigland@xxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
fs/dlm/lock.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -5795,20 +5795,20 @@ int dlm_user_request(struct dlm_ls *ls,
goto out;
}
}
-
- /* After ua is attached to lkb it will be freed by dlm_free_lkb().
- When DLM_IFL_USER is set, the dlm knows that this is a userspace
- lock and that lkb_astparam is the dlm_user_args structure. */
-
error = set_lock_args(mode, &ua->lksb, flags, namelen, timeout_cs,
fake_astfn, ua, fake_bastfn, &args);
- lkb->lkb_flags |= DLM_IFL_USER;
-
if (error) {
+ kfree(ua->lksb.sb_lvbptr);
+ ua->lksb.sb_lvbptr = NULL;
+ kfree(ua);
__put_lkb(ls, lkb);
goto out;
}

+ /* After ua is attached to lkb it will be freed by dlm_free_lkb().
+ When DLM_IFL_USER is set, the dlm knows that this is a userspace
+ lock and that lkb_astparam is the dlm_user_args structure. */
+ lkb->lkb_flags |= DLM_IFL_USER;
error = request_lock(ls, lkb, name, namelen, &args);

switch (error) {