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authorGabriel Krisman Bertazi <krisman@linux.vnet.ibm.com>2016-12-28 16:42:00 -0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-05-08 07:46:02 +0200
commit35c9bfa51154cc3519e93970c69afe13f93757ac (patch)
tree7ebff820149e600276ea19e46b294f578696bc24 /drivers/tty
parent6f81dea4037c878e27e3cb25cabc85c2f897fdfd (diff)
8250_pci: Fix potential use-after-free in error path
commit c130b666a9a711f985a0a44b58699ebe14bb7245 upstream. Commit f209fa03fc9d ("serial: 8250_pci: Detach low-level driver during PCI error recovery") introduces a potential use-after-free in case the pciserial_init_ports call in serial8250_io_resume fails, which may happen if a memory allocation fails or if the .init quirk failed for whatever reason). If this happen, further pci_get_drvdata will return a pointer to freed memory. This patch reworks the PCI recovery resume hook to restore the old priv structure in this case, which should be ok, since the ports were already detached. Such error during recovery causes us to give up on the recovery. Fixes: f209fa03fc9d ("serial: 8250_pci: Detach low-level driver during PCI error recovery") Reported-by: Michal Suchanek <msuchanek@suse.com> Signed-off-by: Gabriel Krisman Bertazi <krisman@linux.vnet.ibm.com> Signed-off-by: Guilherme G. Piccoli <gpiccoli@linux.vnet.ibm.com> Cc: Sumit Semwal <sumit.semwal@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r--drivers/tty/serial/8250/8250_pci.c12
1 files changed, 5 insertions, 7 deletions
diff --git a/drivers/tty/serial/8250/8250_pci.c b/drivers/tty/serial/8250/8250_pci.c
index 83ff1724ec79..cf3da51a3536 100644
--- a/drivers/tty/serial/8250/8250_pci.c
+++ b/drivers/tty/serial/8250/8250_pci.c
@@ -5850,17 +5850,15 @@ static pci_ers_result_t serial8250_io_slot_reset(struct pci_dev *dev)
static void serial8250_io_resume(struct pci_dev *dev)
{
struct serial_private *priv = pci_get_drvdata(dev);
- const struct pciserial_board *board;
+ struct serial_private *new;
if (!priv)
return;
- board = priv->board;
- kfree(priv);
- priv = pciserial_init_ports(dev, board);
-
- if (!IS_ERR(priv)) {
- pci_set_drvdata(dev, priv);
+ new = pciserial_init_ports(dev, priv->board);
+ if (!IS_ERR(new)) {
+ pci_set_drvdata(dev, new);
+ kfree(priv);
}
}