liyinshu has uploaded this change for review. ( https://review.gerrithub.io/c/ffilz/nfs-ganesha/+/542077 ) Change subject: Fix crash at glist_del state_sharelist ...................................................................... Fix crash at glist_del state_sharelist If open_state's ref count is 1, reproduce crash as follows: thread1: nfs4_op_close.c:180 inc open_state's ref to 2. thread2: nfs4_op_lock:178 inc open_state's ref to 3. thread1: nfs4_op_close.c:306 dec open_state's ref to 2. thread1: nfs4_op_close.c:336 dec open_state's ref to 1. thread2: nfs4_op_lock.c:598 add lock_state's state_sharelist to the tail of open_state's share_lockstates. thread2: nfs4_op_lock.c:742 dec open_state's ref to 0 and free this open_state. thread3: nfs4_op_free_stateid.c:120 state_del_locked(lock_state) thread3: nfs4_state.c:458 glist_del(&lock_state->state_data.lock.state_sharelist) thread3: gsh_list.h:102 left->next = right, crash happens, because left is open_state's share_lockstates, and open_state has been freed by thread2, so it's a used after free. The root cause is add lock_state's state_sharelist to the tail of open_state's share_lockstates, and the open_state will be freed immediately. So before this, we check again whether state_open existed in hashtable. Change-Id: Idc3a3171c52e6a86cc2c5c18e353702a34473e9e Signed-off-by: liyinshu <liyinshu(a)bytedance.com&gt; --- A commit-msg M src/Protocols/NFS/nfs4_op_lock.c 2 files changed, 113 insertions(+), 0 deletions(-) git pull ssh://review.gerrithub.io:29418/ffilz/nfs-ganesha refs/changes/77/542077/1 -- To view, visit https://review.gerrithub.io/c/ffilz/nfs-ganesha/+/542077 To unsubscribe, or for help writing mail filters, visit https://review.gerrithub.io/settings Gerrit-Project: ffilz/nfs-ganesha Gerrit-Branch: next Gerrit-Change-Id: Idc3a3171c52e6a86cc2c5c18e353702a34473e9e Gerrit-Change-Number: 542077 Gerrit-PatchSet: 1 Gerrit-Owner: liyinshu <liyinshu(a)bytedance.com&gt; Gerrit-MessageType: newchange