CVE request: Linux kernel: Buffer overflow in HFS plus filesystem

[Timo Warns <warns () pre-sense de>]

The Linux kernel (at least 3.x <= 3.3.4 and 2.6.x <= 2.6.35.13) contains
a vulnerability in the driver for HFS plus file systems that may be
exploited for code execution or privilege escalation.

A specially-crafted HFS plus filesystem can cause a buffer overflow via
the memcpy() call of hfs_bnode_read() (in fs/hfsplus/bnode.c). The functions

        hfsplus_rename_cat() (in fs/hfsplus/catalog.c) and
        hfsplus_readdir() (in fs/hfsplus/dir.c)

call hfs_bnode_read() with values that result in a memcpy() call with a
fixed-length destination buffer and both, a source buffer and length,
that are read from the filesystem without sufficient validation.

The buffer overflows were previously fixed in the HFS filesystem driver
and have been assigned CVE-2009-4020 (commit
ec81aecb29668ad71f699f4e7b96ec46691895b6 [1]).
Commit 6f24f892871acc47b40dd594c63606a17c714f77 ("hfsplus: fix a
potential buffer overflow") [2] also fixes the issue in the HFS plus
filesystem driver.

[1] http://git.kernel.org/linus/ec81aecb29668ad71f699f4e7b96ec46691895b6
[2] http://git.kernel.org/linus/6f24f892871acc47b40dd594c63606a17c714f77