Description
The btrfs_ioctl_clone function in fs/btrfs/ioctl.c in the btrfs functionality in the Linux kernel 2.6.29 through 2.6.32, and possibly other versions, does not ensure that a cloned file descriptor has been opened for reading, which allows local users to read sensitive information from a write-only file descriptor.
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Third-party code, not reviewed by us. Public PoCs are sometimes fake or contain malware. Read the code first and run it only in an isolated lab, against systems you are authorised to test.
Exploit-DB 1
- Linux Kernel 2.6.x - Btrfs Cloned File Security Bypass EDB-34001 · local · May 18, 2010 · verified
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- https://bugs.launchpad.net/ubuntu/+source/linux/+bug/579585
- [oss-security] 20100518 Re: kernel: btrfs: check for read permission on src file in the clone ioctl mailing-list
- [oss-security] 20100518 kernel: btrfs: check for read permission on src file in the clone ioctl mailing-list
- [oss-security] 20100525 Re: kernel: btrfs: check for read permission on src file in the clone ioctl mailing-list
- https://bugzilla.redhat.com/show_bug.cgi?id=593226
- http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git%3Ba=commitdiff%3Bh=5dc6416414fb3ec6e2825fd4d20c8bf1d7fe0395