From: Mian Yousaf Kaukab ykaukab@suse.de
commit 34f35f8f14bc406efc06ee4ff73202c6fd245d15 upstream.
During probe ssif_info->client is dereferenced in error path. However, it is set when some of the error checking has already been done. This causes following kernel crash if an error path is taken:
[ 30.645593][ T674] ipmi_ssif 0-000e: ipmi_ssif: Not probing, Interface already present [ 30.657616][ T674] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000088 ... [ 30.657723][ T674] pc : __dev_printk+0x28/0xa0 [ 30.657732][ T674] lr : _dev_err+0x7c/0xa0 ... [ 30.657772][ T674] Call trace: [ 30.657775][ T674] __dev_printk+0x28/0xa0 [ 30.657778][ T674] _dev_err+0x7c/0xa0 [ 30.657781][ T674] ssif_probe+0x548/0x900 [ipmi_ssif 62ce4b08badc1458fd896206d9ef69a3c31f3d3e] [ 30.657791][ T674] i2c_device_probe+0x37c/0x3c0 ...
Initialize ssif_info->client before any error path can be taken. Clear i2c_client data in the error path to prevent the dangling pointer from leaking.
Fixes: c4436c9149c5 ("ipmi_ssif: avoid registering duplicate ssif interface") Cc: stable@vger.kernel.org # 5.4.x Suggested-by: Takashi Iwai tiwai@suse.de Signed-off-by: Mian Yousaf Kaukab ykaukab@suse.de Message-Id: 20211208093239.4432-1-ykaukab@suse.de Signed-off-by: Corey Minyard cminyard@mvista.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/char/ipmi/ipmi_ssif.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/char/ipmi/ipmi_ssif.c +++ b/drivers/char/ipmi/ipmi_ssif.c @@ -1659,6 +1659,9 @@ static int ssif_probe(struct i2c_client } }
+ ssif_info->client = client; + i2c_set_clientdata(client, ssif_info); + rv = ssif_check_and_remove(client, ssif_info); /* If rv is 0 and addr source is not SI_ACPI, continue probing */ if (!rv && ssif_info->addr_source == SI_ACPI) { @@ -1679,9 +1682,6 @@ static int ssif_probe(struct i2c_client ipmi_addr_src_to_str(ssif_info->addr_source), client->addr, client->adapter->name, slave_addr);
- ssif_info->client = client; - i2c_set_clientdata(client, ssif_info); - /* Now check for system interface capabilities */ msg[0] = IPMI_NETFN_APP_REQUEST << 2; msg[1] = IPMI_GET_SYSTEM_INTERFACE_CAPABILITIES_CMD; @@ -1881,6 +1881,7 @@ static int ssif_probe(struct i2c_client
dev_err(&ssif_info->client->dev, "Unable to start IPMI SSIF: %d\n", rv); + i2c_set_clientdata(client, NULL); kfree(ssif_info); } kfree(resp);