The sg implementation in the Linux kernel through 4.9 does not properly restrict write operations in situations where the KERNEL_DS option is set, which allows local users to read or write to arbitrary kernel memory locations or cause a denial of service (use-after-free) by leveraging access to a /dev/sg device, related to block/bsg.c and drivers/scsi/sg.c. NOTE: this vulnerability exists because of an incomplete fix for CVE-2016-9576.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| http://www.securitytracker.com/id/1037538 | vdb entry third party advisory |
| https://access.redhat.com/errata/RHSA-2017:2669 | third party advisory vendor advisory |
| http://www.securityfocus.com/bid/95169 | vdb entry third party advisory |
| http://rhn.redhat.com/errata/RHSA-2017-0817.html | third party advisory vendor advisory |
| http://www.openwall.com/lists/oss-security/2016/12/30/1 | third party advisory mailing list |
| https://access.redhat.com/errata/RHSA-2017:2077 | third party advisory vendor advisory |
| http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=128394eff343fc6d2f32172f03e24829539c5835 | patch vendor advisory |
| https://access.redhat.com/errata/RHSA-2017:1842 | third party advisory vendor advisory |
| https://github.com/torvalds/linux/commit/128394eff343fc6d2f32172f03e24829539c5835 | patch vendor advisory |