]> git.karo-electronics.de Git - karo-tx-linux.git/commit
staging: comedi: fix memory leak for saved channel list
authorIan Abbott <abbotti@mev.co.uk>
Wed, 19 Sep 2012 18:37:39 +0000 (19:37 +0100)
committerBen Hutchings <ben@decadent.org.uk>
Wed, 17 Oct 2012 02:48:39 +0000 (03:48 +0100)
commit2a522045b7ede8773e4966b427391184a2b81d0c
tree43e732494248a78b36b4bc2f8d5d6c1a5aad1ea0
parentfda55976471f47647592f59b14a907fe2c0d38a0
staging: comedi: fix memory leak for saved channel list

commit c8cad4c89ee3b15935c532210ae6ebb5c0a2734d upstream.

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associated with the channel list is no longer valid.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.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
drivers/staging/comedi/comedi_fops.c