[PATCH] Fix rundown crashes

[Volker Lendecke]

Hi!

Review appreciated!

Thanks, Volker

-- 
SerNet GmbH, Bahnhofsallee 1b, 37081 Göttingen
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From 14c4145070e5ad48b000cdd852b4c57ae819e16a Mon Sep 17 00:00:00 2001
From: Volker Lendecke <vl at samba.org>
Date: Wed, 19 Jul 2017 14:51:33 +0200
Subject: [PATCH] smbd: Fix a connection run-down race condition

When we do a server exit with active aio jobs, we need to keep the
aio state active for the helper thread. Right now I don't see another
chance than to leak memory in this case. And, I don't really oversee
how cancelling requests works in this case, but this does fix crashes
seen at a customer site.

Signed-off-by: Volker Lendecke <vl at samba.org>
---
 source3/modules/vfs_default.c | 33 +++++++++++++++++++++++++++------
 1 file changed, 27 insertions(+), 6 deletions(-)

diff --git a/source3/modules/vfs_default.c b/source3/modules/vfs_default.c
index bf857b6b1ca..fbfe654f1fd 100644
--- a/source3/modules/vfs_default.c
+++ b/source3/modules/vfs_default.c
@@ -750,6 +750,7 @@ struct vfswrap_pread_state {
 
 static void vfs_pread_do(void *private_data);
 static void vfs_pread_done(struct tevent_req *subreq);
+static int vfs_pread_state_destructor(struct vfswrap_pread_state *state);
 
 static struct tevent_req *vfswrap_pread_send(struct vfs_handle_struct *handle,
 					     TALLOC_CTX *mem_ctx,
@@ -790,6 +791,8 @@ static struct tevent_req *vfswrap_pread_send(struct vfs_handle_struct *handle,
 	}
 	tevent_req_set_callback(subreq, vfs_pread_done, req);
 
+	talloc_set_destructor(state, vfs_pread_state_destructor);
+
 	return req;
 }
 
@@ -818,19 +821,23 @@ static void vfs_pread_do(void *private_data)
 	SMBPROFILE_BYTES_ASYNC_SET_IDLE(state->profile_bytes);
 }
 
+static int vfs_pread_state_destructor(struct vfswrap_pread_state *state)
+{
+	return -1;
+}
+
 static void vfs_pread_done(struct tevent_req *subreq)
 {
 	struct tevent_req *req = tevent_req_callback_data(
 		subreq, struct tevent_req);
-#ifdef WITH_PROFILE
 	struct vfswrap_pread_state *state = tevent_req_data(
 		req, struct vfswrap_pread_state);
-#endif
 	int ret;
 
 	ret = pthreadpool_tevent_job_recv(subreq);
 	TALLOC_FREE(subreq);
 	SMBPROFILE_BYTES_ASYNC_END(state->profile_bytes);
+	talloc_set_destructor(state, NULL);
 	if (tevent_req_error(req, ret)) {
 		return;
 	}
@@ -866,6 +873,7 @@ struct vfswrap_pwrite_state {
 
 static void vfs_pwrite_do(void *private_data);
 static void vfs_pwrite_done(struct tevent_req *subreq);
+static int vfs_pwrite_state_destructor(struct vfswrap_pwrite_state *state);
 
 static struct tevent_req *vfswrap_pwrite_send(struct vfs_handle_struct *handle,
 					      TALLOC_CTX *mem_ctx,
@@ -906,6 +914,8 @@ static struct tevent_req *vfswrap_pwrite_send(struct vfs_handle_struct *handle,
 	}
 	tevent_req_set_callback(subreq, vfs_pwrite_done, req);
 
+	talloc_set_destructor(state, vfs_pwrite_state_destructor);
+
 	return req;
 }
 
@@ -934,19 +944,23 @@ static void vfs_pwrite_do(void *private_data)
 	SMBPROFILE_BYTES_ASYNC_SET_IDLE(state->profile_bytes);
 }
 
+static int vfs_pwrite_state_destructor(struct vfswrap_pwrite_state *state)
+{
+	return -1;
+}
+
 static void vfs_pwrite_done(struct tevent_req *subreq)
 {
 	struct tevent_req *req = tevent_req_callback_data(
 		subreq, struct tevent_req);
-#ifdef WITH_PROFILE
 	struct vfswrap_pwrite_state *state = tevent_req_data(
 		req, struct vfswrap_pwrite_state);
-#endif
 	int ret;
 
 	ret = pthreadpool_tevent_job_recv(subreq);
 	TALLOC_FREE(subreq);
 	SMBPROFILE_BYTES_ASYNC_END(state->profile_bytes);
+	talloc_set_destructor(state, NULL);
 	if (tevent_req_error(req, ret)) {
 		return;
 	}
@@ -979,6 +993,7 @@ struct vfswrap_fsync_state {
 
 static void vfs_fsync_do(void *private_data);
 static void vfs_fsync_done(struct tevent_req *subreq);
+static int vfs_fsync_state_destructor(struct vfswrap_fsync_state *state);
 
 static struct tevent_req *vfswrap_fsync_send(struct vfs_handle_struct *handle,
 					     TALLOC_CTX *mem_ctx,
@@ -1012,6 +1027,8 @@ static struct tevent_req *vfswrap_fsync_send(struct vfs_handle_struct *handle,
 	}
 	tevent_req_set_callback(subreq, vfs_fsync_done, req);
 
+	talloc_set_destructor(state, vfs_fsync_state_destructor);
+
 	return req;
 }
 
@@ -1035,19 +1052,23 @@ static void vfs_fsync_do(void *private_data)
 	state->vfs_aio_state.duration = nsec_time_diff(&end_time, &start_time);
 }
 
+static int vfs_fsync_state_destructor(struct vfswrap_fsync_state *state)
+{
+	return -1;
+}
+
 static void vfs_fsync_done(struct tevent_req *subreq)
 {
 	struct tevent_req *req = tevent_req_callback_data(
 		subreq, struct tevent_req);
-#ifdef WITH_PROFILE
 	struct vfswrap_fsync_state *state = tevent_req_data(
 		req, struct vfswrap_fsync_state);
-#endif
 	int ret;
 
 	ret = pthreadpool_tevent_job_recv(subreq);
 	TALLOC_FREE(subreq);
 	SMBPROFILE_BASIC_ASYNC_END(state->profile_basic);
+	talloc_set_destructor(state, NULL);
 	if (tevent_req_error(req, ret)) {
 		return;
 	}
-- 
2.11.0