From 7692700ac818866d138a8de555130a6e70e6ac16 Mon Sep 17 00:00:00 2001 From: Phil Auld Date: Thu, 17 Nov 2022 11:23:13 -0500 Subject: [PATCH] hwmon: (coretemp) Check for null before removing sysfs attrs [ Upstream commit a89ff5f5cc64b9fe7a992cf56988fd36f56ca82a ] If coretemp_add_core() gets an error then pdata->core_data[indx] is already NULL and has been kfreed. Don't pass that to sysfs_remove_group() as that will crash in sysfs_remove_group(). [Shortened for readability] [91854.020159] sysfs: cannot create duplicate filename '/devices/platform/coretemp.0/hwmon/hwmon2/temp20_label' [91855.126115] BUG: kernel NULL pointer dereference, address: 0000000000000188 [91855.165103] #PF: supervisor read access in kernel mode [91855.194506] #PF: error_code(0x0000) - not-present page [91855.224445] PGD 0 P4D 0 [91855.238508] Oops: 0000 [#1] PREEMPT SMP PTI ... [91855.342716] RIP: 0010:sysfs_remove_group+0xc/0x80 ... [91855.796571] Call Trace: [91855.810524] coretemp_cpu_offline+0x12b/0x1dd [coretemp] [91855.841738] ? coretemp_cpu_online+0x180/0x180 [coretemp] [91855.871107] cpuhp_invoke_callback+0x105/0x4b0 [91855.893432] cpuhp_thread_fun+0x8e/0x150 ... Fix this by checking for NULL first. Signed-off-by: Phil Auld Cc: linux-hwmon@vger.kernel.org Cc: Fenghua Yu Cc: Jean Delvare Cc: Guenter Roeck Link: https://lore.kernel.org/r/20221117162313.3164803-1-pauld@redhat.com Fixes: 199e0de7f5df3 ("hwmon: (coretemp) Merge pkgtemp with coretemp") Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin --- drivers/hwmon/coretemp.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/hwmon/coretemp.c b/drivers/hwmon/coretemp.c index 032129292957..9b49bfc63ffc 100644 --- a/drivers/hwmon/coretemp.c +++ b/drivers/hwmon/coretemp.c @@ -533,6 +533,10 @@ static void coretemp_remove_core(struct platform_data *pdata, int indx) { struct temp_data *tdata = pdata->core_data[indx]; + /* if we errored on add then this is already gone */ + if (!tdata) + return; + /* Remove the sysfs attributes */ sysfs_remove_group(&pdata->hwmon_dev->kobj, &tdata->attr_group);