Messages in this thread | | | Date | Mon, 24 Jan 2011 20:51:30 +0100 (CET) | From | Jesper Juhl <> | Subject | Re: [PATCH] autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd() |
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Hi Ian,
On Sat, 18 Dec 2010, Jesper Juhl wrote:
> Hi, > > In fs/autofs4/dev-ioctl.c::autofs_dev_ioctl_setpipefd() we call fget(), > which may return NULL, but we do not explicitly test for that NULL return > so we may end up dereferencing a NULL pointer - bad. > > When I originally submitted this patch I had chosen EBUSY as the return > value to use if this happens. Ian Kent was kind enough to explain why that > would most likely be wrong and why EBADF should most likely be used > instead. This version of the patch uses EBADF. > > > Signed-off-by: Jesper Juhl <jj@chaosbits.net> > --- > dev-ioctl.c | 4 ++++ > 1 file changed, 4 insertions(+) > > diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c > index eff9a41..a650d7e 100644 > --- a/fs/autofs4/dev-ioctl.c > +++ b/fs/autofs4/dev-ioctl.c > @@ -372,6 +372,10 @@ static int autofs_dev_ioctl_setpipefd(struct file *fp, > return -EBUSY; > } else { > struct file *pipe = fget(pipefd); > + if (!pipe) { > + err = -EBADF; > + goto out; > + } > if (!pipe->f_op || !pipe->f_op->write) { > err = -EPIPE; > fput(pipe); >
It's been more than a month now since I submitted this updated patch adressing your feedback, but I've not seen any feedback on it. Is it OK? Will you merge it?
/Jesper
-- Jesper Juhl <jj@chaosbits.net> http://www.chaosbits.net/ Don't top-post http://www.catb.org/~esr/jargon/html/T/top-post.html Plain text mails only, please.
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