diff options
| author | Ian Abbott | 2012-09-19 20:37:39 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2012-09-21 18:29:53 +0200 |
| commit | c8cad4c89ee3b15935c532210ae6ebb5c0a2734d (patch) | |
| tree | 23f09ff365e82104797fc0dccb9084c4eef0088d /drivers/staging/comedi/comedi_fops.c | |
| parent | staging: comedi: ni_labpc: pass ai scan mode through various functions (diff) | |
| download | kernel-qcow2-linux-c8cad4c89ee3b15935c532210ae6ebb5c0a2734d.tar.gz kernel-qcow2-linux-c8cad4c89ee3b15935c532210ae6ebb5c0a2734d.tar.xz kernel-qcow2-linux-c8cad4c89ee3b15935c532210ae6ebb5c0a2734d.zip | |
staging: comedi: fix memory leak for saved channel list
When `do_cmd_ioctl()` allocates memory for the kernel copy of a channel
list, it frees any previously allocated channel list in
`async->cmd.chanlist` and replaces it with the new one. However, if the
device is ever removed (or "detached") the cleanup code in
`cleanup_device()` in "drivers.c" does not free this memory so it is
lost.
A sensible place to free the kernel copy of the channel list is in
`do_become_nonbusy()` as at that point the comedi asynchronous command
associated with the channel list is no longer valid. Free the channel
list in `do_become_nonbusy()` instead of `do_cmd_ioctl()` and clear the
pointer to prevent it being freed more than once.
Note that `cleanup_device()` could be called at an inappropriate time
while the comedi device is open, but that's a separate bug not related
to this this patch.
Cc: stable@vger.kernel.org
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/comedi/comedi_fops.c')
| -rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index f496f4d96c83..c2a32cf95a82 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -1195,7 +1195,6 @@ static int do_cmd_ioctl(struct comedi_device *dev, goto cleanup; } - kfree(async->cmd.chanlist); async->cmd = cmd; async->cmd.data = NULL; /* load channel/gain list */ @@ -2033,6 +2032,8 @@ static void do_become_nonbusy(struct comedi_device *dev, if (async) { comedi_reset_async_buf(async); async->inttrig = NULL; + kfree(async->cmd.chanlist); + async->cmd.chanlist = NULL; } else { dev_err(dev->class_dev, "BUG: (?) do_become_nonbusy called with async=NULL\n"); |