https://github.com/torvalds/linux
Revision 22a1e7783e173ab3d86018eb590107d68df46c11 authored by Takashi Iwai on 17 November 2016, 09:49:31 UTC, committed by Mauro Carvalho Chehab on 23 November 2016, 23:04:26 UTC
The commit 8dfbcc4351a0 ("[media] xc2028: avoid use after free") tried
to address the reported use-after-free by clearing the reference.
However, it's clearing the wrong pointer; it sets NULL to
priv->ctrl.fname, but it's anyway overwritten by the next line
memcpy(&priv->ctrl, p, sizeof(priv->ctrl)).
OTOH, the actual code accessing the freed string is the strcmp() call
with priv->fname:
if (!firmware_name[0] && p->fname &&
priv->fname && strcmp(p->fname, priv->fname))
free_firmware(priv);
where priv->fname points to the previous file name, and this was
already freed by kfree().
For fixing the bug properly, this patch does the following:
- Keep the copy of firmware file name in only priv->fname,
priv->ctrl.fname isn't changed;
- The allocation is done only when the firmware gets loaded;
- The kfree() is called in free_firmware() commonly
Fixes: commit 8dfbcc4351a0 ('[media] xc2028: avoid use after free')
Cc: <stable@vger.kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
1 parent 9c76358
Tip revision: 22a1e7783e173ab3d86018eb590107d68df46c11 authored by Takashi Iwai on 17 November 2016, 09:49:31 UTC
xc2028: Fix use-after-free bug properly
xc2028: Fix use-after-free bug properly
Tip revision: 22a1e77
| File | Mode | Size |
|---|---|---|
| Documentation | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| firmware | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .cocciconfig | -rw-r--r-- | 59 bytes |
| .get_maintainer.ignore | -rw-r--r-- | 31 bytes |
| .gitattributes | -rw-r--r-- | 30 bytes |
| .gitignore | -rw-r--r-- | 1.3 KB |
| .mailmap | -rw-r--r-- | 7.5 KB |
| COPYING | -rw-r--r-- | 18.3 KB |
| CREDITS | -rw-r--r-- | 96.0 KB |
| Kbuild | -rw-r--r-- | 2.8 KB |
| Kconfig | -rw-r--r-- | 252 bytes |
| MAINTAINERS | -rw-r--r-- | 373.5 KB |
| Makefile | -rw-r--r-- | 57.5 KB |
| README | -rw-r--r-- | 17.9 KB |
| REPORTING-BUGS | -rw-r--r-- | 7.3 KB |
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