diff options
| author | Alexander Shishkin <alexander.shishkin@linux.intel.com> | 2019-02-21 14:19:17 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-03-23 14:35:17 +0100 |
| commit | e713b0f4b480d671c495f542d769c8c6725c2dbd (patch) | |
| tree | ebd93fb2a63ef19f6aa1dde04541c425c1a65a5d /drivers/hwtracing | |
| parent | 8d6df5097c0005320ab6f3cd8dda2ef31db6c6d1 (diff) | |
stm class: Prevent division by zero
commit bf7cbaae0831252b416f375ca9b1027ecd4642dd upstream.
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+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 88a79b45b80c..41724d18e712 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -561,7 +561,7 @@ 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; - int ret = -EINVAL; + int ret = -EINVAL, wlimit = 1; u32 size; if (stmf->output.nr_chans) @@ -589,8 +589,10 @@ 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; ret = stm_file_assign(stmf, id->id, id->width); |