Description

The ext4_xattr_check_entries function in fs/ext4/xattr.c in the Linux kernel through 4.15.15 does not properly validate xattr sizes, which causes misinterpretation of a size as an error code, and consequently allows attackers to cause a denial of service (get_acl NULL pointer dereference and system crash) via a crafted ext4 image.

References

http://openwall.com/lists/oss-security/2018/03/29/1

https://access.redhat.com/errata/RHSA-2018:2948

https://bugzilla.kernel.org/show_bug.cgi?id=199185

https://bugzilla.redhat.com/show_bug.cgi?id=1560793

https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git/commit/?id=ce3fd194fcc6fbdc00ce095a852f22df97baa401

https://usn.ubuntu.com/3695-1/

https://usn.ubuntu.com/3695-2/

Details

Risk Information

CVSS v2

CVSS v3