From 0f80985965736400df4f1a85bb17d540a7d5ee67 Mon Sep 17 00:00:00 2001 From: Daniel Okazaki Date: Mon, 22 Apr 2024 17:43:36 +0000 Subject: [PATCH] eeprom: at24: fix memory corruption race condition BugLink: https://bugs.launchpad.net/bugs/2070337 commit f42c97027fb75776e2e9358d16bf4a99aeb04cf2 upstream. If the eeprom is not accessible, an nvmem device will be registered, the read will fail, and the device will be torn down. If another driver accesses the nvmem device after the teardown, it will reference invalid memory. Move the failure point before registering the nvmem device. Signed-off-by: Daniel Okazaki Fixes: b20eb4c1f026 ("eeprom: at24: drop unnecessary label") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20240422174337.2487142-1-dtokazaki@google.com Signed-off-by: Bartosz Golaszewski Signed-off-by: Greg Kroah-Hartman Signed-off-by: Manuel Diewald Signed-off-by: Stefan Bader --- drivers/misc/eeprom/at24.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/drivers/misc/eeprom/at24.c b/drivers/misc/eeprom/at24.c index 572333ead5fb..4bd4f32bcdab 100644 --- a/drivers/misc/eeprom/at24.c +++ b/drivers/misc/eeprom/at24.c @@ -758,15 +758,6 @@ static int at24_probe(struct i2c_client *client) } pm_runtime_enable(dev); - at24->nvmem = devm_nvmem_register(dev, &nvmem_config); - if (IS_ERR(at24->nvmem)) { - pm_runtime_disable(dev); - if (!pm_runtime_status_suspended(dev)) - regulator_disable(at24->vcc_reg); - return dev_err_probe(dev, PTR_ERR(at24->nvmem), - "failed to register nvmem\n"); - } - /* * Perform a one-byte test read to verify that the chip is functional, * unless powering on the device is to be avoided during probe (i.e. @@ -782,6 +773,15 @@ static int at24_probe(struct i2c_client *client) } } + at24->nvmem = devm_nvmem_register(dev, &nvmem_config); + if (IS_ERR(at24->nvmem)) { + pm_runtime_disable(dev); + if (!pm_runtime_status_suspended(dev)) + regulator_disable(at24->vcc_reg); + return dev_err_probe(dev, PTR_ERR(at24->nvmem), + "failed to register nvmem\n"); + } + /* If this a SPD EEPROM, probe for DDR3 thermal sensor */ if (cdata == &at24_data_spd) at24_probe_temp_sensor(client);