From a9d55bb3d7d8bd9137ad234e35987b018d723645 Mon Sep 17 00:00:00 2001 From: Shaun Ruffell Date: Fri, 21 Jan 2011 05:31:26 +0000 Subject: [PATCH] dahdi: Prevent unloadable module on failed open. If chan->span->ops->open() fails then the reference count of the module implementing the board driver will not be decremented. The result is a module that would always be "in use" and unloadable. This change makes sure to release that reference when open failed. (closes issue #18422) Reported by: avarvit Signed-off-by: Shaun Ruffell Acked-by: Angelos Varvitsiotis Origin: http://svnview.digium.com/svn/dahdi?view=rev&rev=9510 git-svn-id: http://svn.asterisk.org/svn/dahdi/linux/branches/2.4@9682 a0bf4364-ded3-4de4-8d8a-66a801d63aff --- drivers/dahdi/dahdi-base.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/dahdi/dahdi-base.c b/drivers/dahdi/dahdi-base.c index 3ecd5c8..247f1f5 100644 --- a/drivers/dahdi/dahdi-base.c +++ b/drivers/dahdi/dahdi-base.c @@ -2789,6 +2789,7 @@ static int dahdi_specchan_open(struct file *file, int unit) res = -EBUSY; else if (!test_and_set_bit(DAHDI_FLAGBIT_OPEN, &chan->flags)) { unsigned long flags; + const struct dahdi_span_ops *ops; res = initialize_channel(chan); if (res) { /* Reallocbufs must have failed */ @@ -2799,10 +2800,14 @@ static int dahdi_specchan_open(struct file *file, int unit) if (chan->flags & DAHDI_FLAG_PSEUDO) chan->flags |= DAHDI_FLAG_AUDIO; if (chan->span) { - if (!try_module_get(chan->span->ops->owner)) + ops = chan->span->ops; + if (!try_module_get(ops->owner)) { res = -ENXIO; - else if (chan->span->ops->open) - res = chan->span->ops->open(chan); + } else if (ops->open) { + res = ops->open(chan); + if (res) + module_put(ops->owner); + } } if (!res) { chan->file = file;