bafefc0cf8
The coverity checker detected a use-after-free error in drivers/media/video/cpia2/cpia2_v4l.c::cpia2_close() (coverity error #1281). What happens is that we lock cam->busy_lock, then proceed to free resources, and in the case of (--cam->open_count == 0) we finish off by doing a kfree(cam) and then at the end of the function we do a mutex_unlock(&cam->busy_lock) which will explode since it'll dereference the free'd `cam' : ... mutex_lock(&cam->busy_lock); ... if (--cam->open_count == 0) { ... if (!cam->present) { video_unregister_device(dev); kfree(cam); } } mutex_unlock(&cam->busy_lock); <--- PROBLEM, cam no longer around. ... Since this only happens in the case of open_count going down to zero I don't see a problem with just releasing the mutex after unregistering the device and just before the kfree(). In this case there is nothing around that we can race against; we are in the release method, open_count is zero, (!cam->present) and the device has just been unregistered, so letting go of the mutex at this point looks safe to me. Patch below to implement that solution. Acked-by: Randy Dunlap <rdunlap@xenotime.net> Signed-off-by: Jesper Juhl <jesper.juhl@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org> |
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| acorn | ||
| acpi | ||
| amba | ||
| atm | ||
| base | ||
| block | ||
| bluetooth | ||
| cdrom | ||
| char | ||
| connector | ||
| cpufreq | ||
| crypto | ||
| dio | ||
| dma | ||
| edac | ||
| eisa | ||
| fc4 | ||
| firmware | ||
| hwmon | ||
| i2c | ||
| ide | ||
| ieee1394 | ||
| infiniband | ||
| input | ||
| isdn | ||
| leds | ||
| macintosh | ||
| mca | ||
| md | ||
| media | ||
| message | ||
| mfd | ||
| misc | ||
| mmc | ||
| mtd | ||
| net | ||
| nubus | ||
| oprofile | ||
| parisc | ||
| parport | ||
| pci | ||
| pcmcia | ||
| pnp | ||
| rapidio | ||
| rtc | ||
| s390 | ||
| sbus | ||
| scsi | ||
| serial | ||
| sh | ||
| sn | ||
| spi | ||
| tc | ||
| telephony | ||
| usb | ||
| video | ||
| w1 | ||
| zorro | ||
| Kconfig | ||
| Makefile | ||