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| author | Xiyu Yang <xiyuyang19@fudan.edu.cn> | 2020-04-20 13:44:16 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-04-23 13:45:24 +0200 |
| commit | 332e0e17ad49e084b7db670ef43b5eb59abd9e34 (patch) | |
| tree | 11a7692ca70aacb3d03d1023776630546063c2a4 /drivers/staging | |
| parent | 0b59f10b1d8fe8d50944f21f5d403df9303095a8 (diff) | |
| download | linux-stable-332e0e17ad49e084b7db670ef43b5eb59abd9e34.tar.gz linux-stable-332e0e17ad49e084b7db670ef43b5eb59abd9e34.tar.bz2 linux-stable-332e0e17ad49e084b7db670ef43b5eb59abd9e34.zip | |
staging: comedi: Fix comedi_device refcnt leak in comedi_open
comedi_open() invokes comedi_dev_get_from_minor(), which returns a
reference of the COMEDI device to "dev" with increased refcount.
When comedi_open() returns, "dev" becomes invalid, so the refcount
should be decreased to keep refcount balanced.
The reference counting issue happens in one exception handling path of
comedi_open(). When "cfp" allocation is failed, the refcnt increased by
comedi_dev_get_from_minor() is not decreased, causing a refcnt leak.
Fix this issue by calling comedi_dev_put() on this error path when "cfp"
allocation is failed.
Fixes: 20f083c07565 ("staging: comedi: prepare support for per-file read and write subdevices")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/1587361459-83622-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging')
| -rw-r--r-- | drivers/staging/comedi/comedi_fops.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c index 08d1bbbebf2d..e84b4fb493d6 100644 --- a/drivers/staging/comedi/comedi_fops.c +++ b/drivers/staging/comedi/comedi_fops.c @@ -2725,8 +2725,10 @@ static int comedi_open(struct inode *inode, struct file *file) } cfp = kzalloc(sizeof(*cfp), GFP_KERNEL); - if (!cfp) + if (!cfp) { + comedi_dev_put(dev); return -ENOMEM; + } cfp->dev = dev; |