The __get_data_block function in fs/f2fs/data.c in the Linux kernel before 4.11 allows local users to cause a denial of service (integer overflow and loop) via crafted use of the open and fallocate system calls with an FS_IOC_FIEMAP ioctl.
The product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.
| Link | Tags |
|---|---|
| https://usn.ubuntu.com/3696-1/ | vendor advisory |
| http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=b86e33075ed1909d8002745b56ecf73b833db143 | patch |
| https://github.com/torvalds/linux/commit/b86e33075ed1909d8002745b56ecf73b833db143 | patch |
| https://www.debian.org/security/2018/dsa-4188 | third party advisory vendor advisory |
| https://usn.ubuntu.com/3696-2/ | vendor advisory |