Re: [PATCH v10 3/7] i2c: fsi: Add port structures
From: Joel Stanley <joel@jms.id.au>
Date: 2018-06-20 03:59:32
Also in:
linux-i2c, lkml
On 20 June 2018 at 13:04, Benjamin Herrenschmidt [off-list ref] wrote:
On Wed, 2018-06-13 at 14:36 -0500, Eddie James wrote:quoted
} +static int fsi_i2c_remove(struct device *dev) +{ + struct fsi_i2c_master *i2c = dev_get_drvdata(dev); + struct fsi_i2c_port *port; + + list_for_each_entry(port, &i2c->ports, list) { + i2c_del_adapter(&port->adapter); + kfree(port); + } + + return 0; +} +This is a use-after-free, the list linkage of the freed port is used to get to the next one. With memory poisoning, kbooom ! You can fold that in: From f9d9092160897e7308f6990067a03e937339537f Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt <benh@kernel.crashing.org> Date: Wed, 20 Jun 2018 13:27:32 +1000 Subject: [PATCH] i2c: fsi: Fix use after free
This fixes the issue I was seeing. For the series: Tested-by: Joel Stanley <joel@jms.id.au> Thanks, Joel
quoted hunk ↗ jump to hunk
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- drivers/i2c/busses/i2c-fsi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)diff --git a/drivers/i2c/busses/i2c-fsi.c b/drivers/i2c/busses/i2c-fsi.c index 713959b44403..ff69ab6aa79a 100644 --- a/drivers/i2c/busses/i2c-fsi.c +++ b/drivers/i2c/busses/i2c-fsi.c@@ -696,9 +696,10 @@ static int fsi_i2c_probe(struct device *dev) static int fsi_i2c_remove(struct device *dev) { struct fsi_i2c_master *i2c = dev_get_drvdata(dev); - struct fsi_i2c_port *port; + struct fsi_i2c_port *port, *tmp; - list_for_each_entry(port, &i2c->ports, list) { + list_for_each_entry_safe(port,tmp, &i2c->ports, list) { + list_del(&port->list); i2c_del_adapter(&port->adapter); kfree(port); }