diff options
| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-02-21 15:19:17 +0300 |
|---|---|---|
| committer | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-02-21 18:44:18 +0300 |
| commit | bf7cbaae0831252b416f375ca9b1027ecd4642dd (patch) | |
| tree | 4cb6da8afa3f5081b5e3ab7c2c8e2197c9aa7325 /drivers/hwtracing | |
| parent | a1d75dad3a2c689e70a1c4e0214cca9de741d0aa (diff) | |
| download | linux-bf7cbaae0831252b416f375ca9b1027ecd4642dd.tar.xz | |
stm class: Prevent division by zero
Using STP_POLICY_ID_SET ioctl command with dummy_stm device, or any STM
device that supplies zero mmio channel size, will trigger a division by
zero bug in the kernel.
Prevent this by disallowing channel widths other than 1 for such devices.
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Fixes: 7bd1d4093c2f ("stm class: Introduce an abstraction for System Trace Module devices")
CC: stable@vger.kernel.org # v4.4+
Diffstat (limited to 'drivers/hwtracing')
| -rw-r--r-- | drivers/hwtracing/stm/core.c | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index c80b064224f6..c7ba8acfd4d5 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -735,7 +735,7 @@ static int stm_char_policy_set_ioctl(struct stm_file *stmf, void __user *arg) struct stm_device *stm = stmf->stm; struct stp_policy_id *id; char *ids[] = { NULL, NULL }; - int ret = -EINVAL; + int ret = -EINVAL, wlimit = 1; u32 size; if (stmf->output.nr_chans) @@ -763,8 +763,10 @@ static int stm_char_policy_set_ioctl(struct stm_file *stmf, void __user *arg) if (id->__reserved_0 || id->__reserved_1) goto err_free; - if (id->width < 1 || - id->width > PAGE_SIZE / stm->data->sw_mmiosz) + if (stm->data->sw_mmiosz) + wlimit = PAGE_SIZE / stm->data->sw_mmiosz; + + if (id->width < 1 || id->width > wlimit) goto err_free; ids[0] = id->id; |