From e61d2392253220477813b43412090dccdcac601f Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Thu, 20 Feb 2020 06:29:48 -0800 Subject: [PATCH] hwmon: (w83627ehf) Fix crash seen with W83627DHG-P Loading the driver on a system with W83627DHG-P crashes as follows. w83627ehf: Found W83627DHG-P chip at 0x290 BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 0 PID: 604 Comm: sensors Not tainted 5.6.0-rc2-00055-gca7e1fd1026c #29 Hardware name: /D425KT, BIOS MWPNT10N.86A.0132.2013.0726.1534 07/26/2013 RIP: 0010:w83627ehf_read_string+0x27/0x70 [w83627ehf] Code: [... ] RSP: 0018:ffffb95980657df8 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff96caaa7f5218 RCX: 0000000000000000 RDX: 0000000000000015 RSI: 0000000000000001 RDI: ffff96caa736ec08 RBP: 0000000000000000 R08: ffffb95980657e20 R09: 0000000000000001 R10: ffff96caaa635cc0 R11: 0000000000000000 R12: ffff96caa9f7cf00 R13: ffff96caa9ec3d00 R14: ffff96caa9ec3d28 R15: ffff96caa9ec3d40 FS: 00007fbc7c4e2740(0000) GS:ffff96caabc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000129d58000 CR4: 00000000000006f0 Call Trace: ? cp_new_stat+0x12d/0x160 hwmon_attr_show_string+0x37/0x70 [hwmon] dev_attr_show+0x14/0x50 sysfs_kf_seq_show+0xb5/0x1b0 seq_read+0xcf/0x460 vfs_read+0x9b/0x150 ksys_read+0x5f/0xe0 do_syscall_64+0x48/0x190 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ... Temperature labels are not always present. Adjust sysfs attribute visibility accordingly. Reported-by: Meelis Roos Suggested-by: Dr. David Alan Gilbert Reviewed-by: Dr. David Alan Gilbert Cc: Meelis Roos Cc: Dr. David Alan Gilbert Fixes: 266cd5835947 ("hwmon: (w83627ehf) convert to with_info interface") Signed-off-by: Guenter Roeck --- drivers/hwmon/w83627ehf.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c index 7ffadc2da57b53..5a5120121e5072 100644 --- a/drivers/hwmon/w83627ehf.c +++ b/drivers/hwmon/w83627ehf.c @@ -1346,8 +1346,13 @@ w83627ehf_is_visible(const void *drvdata, enum hwmon_sensor_types type, /* channel 0.., name 1.. */ if (!(data->have_temp & (1 << channel))) return 0; - if (attr == hwmon_temp_input || attr == hwmon_temp_label) + if (attr == hwmon_temp_input) return 0444; + if (attr == hwmon_temp_label) { + if (data->temp_label) + return 0444; + return 0; + } if (channel == 2 && data->temp3_val_only) return 0; if (attr == hwmon_temp_max) {