This is a note to let you know that I've just added the patch titled
staging: comedi: fix memory leak for saved channel list
to the 3.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
staging-comedi-fix-memory-leak-for-saved-channel-list.patch
and it can be found in the queue-3.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From c8cad4c89ee3b15935c532210ae6ebb5c0a2734d Mon Sep 17 00:00:00 2001
From: Ian Abbott <[email protected]>
Date: Wed, 19 Sep 2012 19:37:39 +0100
Subject: staging: comedi: fix memory leak for saved channel list
From: Ian Abbott <[email protected]>
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associated with the channel list is no longer valid.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 <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/staging/comedi/comedi_fops.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -1196,7 +1196,6 @@ static int do_cmd_ioctl(struct comedi_de
goto cleanup;
}
- kfree(async->cmd.chanlist);
async->cmd = user_cmd;
async->cmd.data = NULL;
/* load channel/gain list */
@@ -2033,6 +2032,8 @@ void do_become_nonbusy(struct comedi_dev
if (async) {
comedi_reset_async_buf(async);
async->inttrig = NULL;
+ kfree(async->cmd.chanlist);
+ async->cmd.chanlist = NULL;
} else {
printk(KERN_ERR
"BUG: (?) do_become_nonbusy called with async=0\n");
Patches currently in stable-queue which might be from [email protected] are
queue-3.6/staging-comedi-s626-don-t-dereference-insn-data.patch
queue-3.6/staging-comedi-jr3_pci-fix-iomem-dereference.patch
queue-3.6/staging-comedi-fix-memory-leak-for-saved-channel-list.patch
queue-3.6/staging-comedi-don-t-dereference-user-memory-for-insn_inttrig.patch
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