Fix os crash caused by optoe when class switch (sonic-net#413)

When the device is initially set to optoe2, there is an option->client[1].
If echo 3>dev_class is manually set at this time, as for optoe3, option->client[1] is meaningless
but the content is still the address data of optoe2, accessing an illegal address will occur, causing the device to crash.

Set option ->client[1] to NULL when unregistering device

Signed-off-by: philo <philo@micasnetworks.com>

patch/0001-fix-os-crash-caused-by-optoe-when-class-switch.patch

@@ -0,0 +1,36 @@
+From b8ba60c6d604fee3f61e3d1e709e86c785b075f4 Mon Sep 17 00:00:00 2001
+From: philo <philo@micasnetworks.com>
+Date: Mon, 1 Jul 2024 11:03:35 +0800
+Subject: [PATCH] fix os crash caused by optoe when class switch
+
+---
+ drivers/misc/eeprom/optoe.c | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/drivers/misc/eeprom/optoe.c b/drivers/misc/eeprom/optoe.c
+index 9129312a1..a6bdbb9d1 100644
+--- a/drivers/misc/eeprom/optoe.c
++++ b/drivers/misc/eeprom/optoe.c
+@@ -941,8 +941,10 @@ static ssize_t set_dev_class(struct device *dev,
+ } else {
+ /* one-address (eg QSFP) and CMIS family */
+ /* if it exists, remove 0x51 i2c address */
+- if (optoe->client[1])
++ if (optoe->client[1]) {
+ i2c_unregister_device(optoe->client[1]);
++ optoe->client[1] = NULL;
++ }
+ optoe->bin.size = ONE_ADDR_EEPROM_SIZE;
+ optoe->num_addresses = 1;
+ }
+@@ -1226,6 +1228,7 @@ static int optoe_probe(struct i2c_client *client,
+ if (num_addresses == 2) {
+ if (optoe->client[1])
+ i2c_unregister_device(optoe->client[1]);
++ optoe->client[1] = NULL;
+ }
+
+ kfree(optoe->writebuf);
+-- 
+2.25.1
+

patch/series

@@ -214,6 +214,9 @@ cisco-npu-disable-other-bars.patch
 # Security patch
 0001-Change-the-system.map-file-permission-only-readable-.patch
 
+# Micas patches
+0001-fix-os-crash-caused-by-optoe-when-class-switch.patch
+
 #
 #
 ############################################################