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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 20:09:52 +0100 |
commit | eabd7d248e2146abe5909eff29806e8b090dc459 (patch) | |
tree | d9aa953806e28fec54def7c6bb6ff3291bb2fb61 | |
parent | b3139fbb3b00f61218121b36ebe32c82857a57df (diff) | |
download | linux-stable-eabd7d248e2146abe5909eff29806e8b090dc459.tar.gz linux-stable-eabd7d248e2146abe5909eff29806e8b090dc459.tar.bz2 linux-stable-eabd7d248e2146abe5909eff29806e8b090dc459.zip |
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>
-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 1d1a05689053..9d55e104400c 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -553,7 +553,7 @@ 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) @@ -581,8 +581,10 @@ 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); |