diff options
| author | Jason Baron <jbaron@akamai.com> | 2020-08-21 12:20:14 -0400 |
|---|---|---|
| committer | Guenter Roeck <linux@roeck-us.net> | 2020-08-21 11:26:35 -0700 |
| commit | 8aebbbb2d573d0b4afc08b90ac7d73dba2d9da97 (patch) | |
| tree | 6a649d5c629e1a36d5799106278fe4300ea87d41 /drivers/hwmon | |
| parent | 51fb91ed5a6fa855a74731610cd5435d83d6e17f (diff) | |
hwmon: (nct7904) Correct divide by 0
We hit a kernel panic due to a divide by 0 in nct7904_read_fan() for
the hwmon_fan_min case. Extend the check to hwmon_fan_input case as well
for safety.
[ 1656.545650] divide error: 0000 [#1] SMP PTI
[ 1656.545779] CPU: 12 PID: 18010 Comm: sensors Not tainted 5.4.47 #1
[ 1656.546065] RIP: 0010:nct7904_read+0x1e9/0x510 [nct7904]
...
[ 1656.546549] RAX: 0000000000149970 RBX: ffffbd6b86bcbe08 RCX: 0000000000000000
...
[ 1656.547548] Call Trace:
[ 1656.547665] hwmon_attr_show+0x32/0xd0 [hwmon]
[ 1656.547783] dev_attr_show+0x18/0x50
[ 1656.547898] sysfs_kf_seq_show+0x99/0x120
[ 1656.548013] seq_read+0xd8/0x3e0
[ 1656.548127] vfs_read+0x89/0x130
[ 1656.548234] ksys_read+0x7d/0xb0
[ 1656.548342] do_syscall_64+0x48/0x110
[ 1656.548451] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: d65a5102a99f5 ("hwmon: (nct7904) Convert to use new hwmon registration API")
Signed-off-by: Jason Baron <jbaron@akamai.com>
Link: https://lore.kernel.org/r/1598026814-2604-1-git-send-email-jbaron@akamai.com
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Diffstat (limited to 'drivers/hwmon')
| -rw-r--r-- | drivers/hwmon/nct7904.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/drivers/hwmon/nct7904.c b/drivers/hwmon/nct7904.c index b0425694f702..242ff8bee78d 100644 --- a/drivers/hwmon/nct7904.c +++ b/drivers/hwmon/nct7904.c @@ -231,7 +231,7 @@ static int nct7904_read_fan(struct device *dev, u32 attr, int channel, if (ret < 0) return ret; cnt = ((ret & 0xff00) >> 3) | (ret & 0x1f); - if (cnt == 0x1fff) + if (cnt == 0 || cnt == 0x1fff) rpm = 0; else rpm = 1350000 / cnt; @@ -243,7 +243,7 @@ static int nct7904_read_fan(struct device *dev, u32 attr, int channel, if (ret < 0) return ret; cnt = ((ret & 0xff00) >> 3) | (ret & 0x1f); - if (cnt == 0x1fff) + if (cnt == 0 || cnt == 0x1fff) rpm = 0; else rpm = 1350000 / cnt; |