[PATCH 3/3] dlm: memory leaks on error path in dlm_user_request()

From: Vasily Averin
Date: Thu Nov 15 2018 - 05:19:02 EST


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")
Cc: stable@xxxxxxxxxx # 2.6.19

Signed-off-by: Vasily Averin <vvs@xxxxxxxxxxxxx>
---
fs/dlm/lock.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/fs/dlm/lock.c b/fs/dlm/lock.c
index 03d767b94f7b..a928ba008d7d 100644
--- a/fs/dlm/lock.c
+++ b/fs/dlm/lock.c
@@ -5795,20 +5795,20 @@ int dlm_user_request(struct dlm_ls *ls, struct dlm_user_args *ua,
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) {
--
2.17.1