[char-misc 0/2] mei: memory leak fixes

[char-misc 0/2] mei: memory leak fixes

[Tomas Winkler]

A memory leak was detected in the mei driver,
here are two fixes that should address that. 

I suggest this goes to stable as well

Alexander Usyskin (2):
  mei: clear write cb from waiting list on reset
  mei: don't unset read cb ptr on reset

 drivers/misc/mei/client.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

-- 
1.8.5.3

[char-misc 1/2] mei: clear write cb from waiting list on reset

[Tomas Winkler]

From: Alexander Usyskin <alexander.usyskin@intel.com>

Clear write callbacks sitting in write_waiting list on reset.
Otherwise these callbacks are left dangling and cause memory leak.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
 drivers/misc/mei/client.c | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index ae07c38..8bf2034 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -960,8 +960,16 @@ void mei_cl_all_wakeup(struct mei_device *dev)
 void mei_cl_all_write_clear(struct mei_device *dev)
 {
 	struct mei_cl_cb *cb, *next;
+	struct list_head *list;
 
-	list_for_each_entry_safe(cb, next, &dev->write_list.list, list) {
+	list = &dev->write_list.list;
+	list_for_each_entry_safe(cb, next, list, list) {
+		list_del(&cb->list);
+		mei_io_cb_free(cb);
+	}
+
+	list = &dev->write_waiting_list.list;
+	list_for_each_entry_safe(cb, next, list, list) {
 		list_del(&cb->list);
 		mei_io_cb_free(cb);
 	}
-- 
1.8.5.3

[char-misc 2/2] mei: don't unset read cb ptr on reset

[Tomas Winkler]

From: Alexander Usyskin <alexander.usyskin@intel.com>

Don't set read callback to NULL during reset as
this leads to memory leak of both cb and its buffer.
The memory is correctly freed during mei_release.

The memory leak is detectable by kmemleak if
application has open read call while system is going through
suspend/resume.

unreferenced object 0xecead780 (size 64):
  comm "AsyncTask #1", pid 1018, jiffies 4294949621 (age 152.440s)
  hex dump (first 32 bytes):
    00 01 10 00 00 02 20 00 00 bf 30 f1 00 00 00 00  ...... ...0.....
    00 00 00 00 00 00 00 00 36 01 00 00 00 70 da e2  ........6....p..
  backtrace:
    [<c1a60aec>] kmemleak_alloc+0x3c/0xa0
    [<c131ed56>] kmem_cache_alloc_trace+0xc6/0x190
    [<c16243c9>] mei_io_cb_init+0x29/0x50
    [<c1625722>] mei_cl_read_start+0x102/0x360
    [<c16268f3>] mei_read+0x103/0x4e0
    [<c1324b09>] vfs_read+0x89/0x160
    [<c1324d5f>] SyS_read+0x4f/0x80
    [<c1a7b318>] syscall_call+0x7/0xb
    [<ffffffff>] 0xffffffff
unreferenced object 0xe2da7000 (size 512):
  comm "AsyncTask #1", pid 1018, jiffies 4294949621 (age 152.440s)
  hex dump (first 32 bytes):
    00 6c da e2 7c 00 00 00 00 00 00 00 c0 eb 0c 59  .l..|..........Y
    1b 00 00 00 01 00 00 00 02 10 00 00 01 00 00 00  ................
  backtrace:
    [<c1a60aec>] kmemleak_alloc+0x3c/0xa0
    [<c131f127>] __kmalloc+0xe7/0x1d0
    [<c162447e>] mei_io_cb_alloc_resp_buf+0x2e/0x60
    [<c162574c>] mei_cl_read_start+0x12c/0x360
    [<c16268f3>] mei_read+0x103/0x4e0
    [<c1324b09>] vfs_read+0x89/0x160
    [<c1324d5f>] SyS_read+0x4f/0x80
    [<c1a7b318>] syscall_call+0x7/0xb
    [<ffffffff>] 0xffffffff

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
 drivers/misc/mei/client.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/drivers/misc/mei/client.c b/drivers/misc/mei/client.c
index 8bf2034..23455c7 100644
--- a/drivers/misc/mei/client.c
+++ b/drivers/misc/mei/client.c
@@ -926,7 +926,6 @@ void mei_cl_all_disconnect(struct mei_device *dev)
 	list_for_each_entry_safe(cl, next, &dev->file_list, link) {
 		cl->state = MEI_FILE_DISCONNECTED;
 		cl->mei_flow_ctrl_creds = 0;
-		cl->read_cb = NULL;
 		cl->timer_count = 0;
 	}
 }
-- 
1.8.5.3