firestream: fix memory leaks

BugLink: https://bugs.launchpad.net/bugs/1861385
[ Upstream commit fa865ba183d61c1ec8cbcab8573159c3b72b89a4 ]

In fs_open(), 'vcc' is allocated through kmalloc() and assigned to
'atm_vcc->dev_data.' In the following execution, if an error occurs, e.g.,
there is no more free channel, an error code EBUSY or ENOMEM will be
returned. However, 'vcc' is not deallocated, leading to memory leaks. Note
that, in normal cases where fs_open() returns 0, 'vcc' will be deallocated
in fs_close(). But, if fs_open() fails, there is no guarantee that
fs_close() will be invoked.

To fix this issue, deallocate 'vcc' before the error code is returned.

Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/drivers/atm/firestream.c b/drivers/atm/firestream.c
index 2bbab0230aebfaea74da942c17512af4bc162acb..d287837ed755575bc5020e75d0bc19f634b18b4e 100644 (file)
--- a/drivers/atm/firestream.c
+++ b/drivers/atm/firestream.c
@@ -912,6 +912,7 @@ static int fs_open(struct atm_vcc *atm_vcc)
                        }
                        if (!to) {
                                printk ("No more free channels for FS50..\n");
+                               kfree(vcc);
                                return -EBUSY;
                        }
                        vcc->channo = dev->channo;
@@ -922,6 +923,7 @@ static int fs_open(struct atm_vcc *atm_vcc)
                        if (((DO_DIRECTION(rxtp) && dev->atm_vccs[vcc->channo])) ||
                            ( DO_DIRECTION(txtp) && test_bit (vcc->channo, dev->tx_inuse))) {
                                printk ("Channel is in use for FS155.\n");
+                               kfree(vcc);
                                return -EBUSY;
                        }
                }
@@ -935,6 +937,7 @@ static int fs_open(struct atm_vcc *atm_vcc)
                            tc, sizeof (struct fs_transmit_config));
                if (!tc) {
                        fs_dprintk (FS_DEBUG_OPEN, "fs: can't alloc transmit_config.\n");
+                       kfree(vcc);
                        return -ENOMEM;
                }