CVE-2017-18241

Published: 21 March 2018

fs/f2fs/segment.c in the Linux kernel before 4.13 allows local users to cause a denial of service (NULL pointer dereference and panic) by using a noflush_merge option that triggers a NULL value for a flush_cmd_control data structure.

From the Ubuntu security team

It was discovered that the f2fs filesystem implementation in the Linux kernel did not handle the noflush_merge mount option correctly. An attacker could use this to cause a denial of service (system crash).

Priority

Low

CVSS 3 base score: 5.5

Status

Notes

fixes a case in the F2FS_FS, when the fs is mounted with the
'noflush_merge' option, but support for flush coalition was introduced in:
6b4afdd794783fe515b50838aa36591e3feea990

The affected user base for this issue is likely small since f2fs is
not the default filesystem and it is not widely used in Ubuntu

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2017-18241
• http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d4fdf8ba0e5808ba9ad6b44337783bd9935e0982
• https://github.com/torvalds/linux/commit/d4fdf8ba0e5808ba9ad6b44337783bd9935e0982
• https://ubuntu.com/security/notices/USN-3910-1
• https://ubuntu.com/security/notices/USN-3910-2
• NVD
• Launchpad
• Debian

Bugs