* Affected product: Linux Kernel 3.3.x <= 3.3.4
2.6.x <= 2.6.35.13
* Impact: code execution / privilege escalation
* Origin: HFS plus file system
* Credit: Timo Warns (PRESENSE Technologies GmbH)
* CVE Identifier: CVE-2012-2319
Summary
-------
The Linux kernel 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.
Workaround
----------
Compile and use a kernel that does not support the HFS plus file system.
The corresponding configuration key is CONFIG_HFSPLUS_FS.
Solution
--------
A patch is available at
http://git.kernel.org/linus/6f24f892871acc47b40dd594c63606a17c714f77
The issue has been fixed in Linux 3.3.5.
References
----------
[1] http://git.kernel.org/linus/ec81aecb29668ad71f699f4e7b96ec46691895b6
[2] http://git.kernel.org/linus/6f24f892871acc47b40dd594c63606a17c714f77
