| From: Colin Ian King <colin.king@canonical.com> |
| Date: Wed, 31 Jan 2018 12:33:09 -0500 |
| Subject: media: cx25821: prevent out-of-bounds read on array card |
| |
| commit 67300abdbe9f1717532aaf4e037222762716d0f6 upstream. |
| |
| Currently an out of range dev->nr is detected by just reporting the |
| issue and later on an out-of-bounds read on array card occurs because |
| of this. Fix this by checking the upper range of dev->nr with the size |
| of array card (removes the hard coded size), move this check earlier |
| and also exit with the error -ENOSYS to avoid the later out-of-bounds |
| array read. |
| |
| Detected by CoverityScan, CID#711191 ("Out-of-bounds-read") |
| |
| Fixes: commit 02b20b0b4cde ("V4L/DVB (12730): Add conexant cx25821 driver") |
| |
| Signed-off-by: Colin Ian King <colin.king@canonical.com> |
| Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> |
| [hans.verkuil@cisco.com: %ld -> %zd] |
| Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| drivers/media/pci/cx25821/cx25821-core.c | 7 ++++--- |
| 1 file changed, 4 insertions(+), 3 deletions(-) |
| |
| --- a/drivers/media/pci/cx25821/cx25821-core.c |
| +++ b/drivers/media/pci/cx25821/cx25821-core.c |
| @@ -871,6 +871,10 @@ static int cx25821_dev_setup(struct cx25 |
| dev->nr = ++cx25821_devcount; |
| sprintf(dev->name, "cx25821[%d]", dev->nr); |
| |
| + if (dev->nr >= ARRAY_SIZE(card)) { |
| + CX25821_INFO("dev->nr >= %zd", ARRAY_SIZE(card)); |
| + return -ENODEV; |
| + } |
| if (dev->pci->device != 0x8210) { |
| pr_info("%s(): Exiting. Incorrect Hardware device = 0x%02x\n", |
| __func__, dev->pci->device); |
| @@ -887,9 +891,6 @@ static int cx25821_dev_setup(struct cx25 |
| dev->channels[i].sram_channels = &cx25821_sram_channels[i]; |
| } |
| |
| - if (dev->nr > 1) |
| - CX25821_INFO("dev->nr > 1!"); |
| - |
| /* board config */ |
| dev->board = 1; /* card[dev->nr]; */ |
| dev->_max_num_decoders = MAX_DECODERS; |
