Race condition in the tty_fasync function in drivers/char/tty_io.c in the Linux kernel before 2.6.32.6 allows local users to cause a denial of service (NULL pointer dereference and system crash) or possibly have unspecified other impact via unknown vectors, related to the put_tty_queue and __f_setown functions. NOTE: the vulnerability was addressed in a different way in 2.6.32.9.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Linux_kernel | Linux | * | 2.6.32.6 (excluding) |
| MRG for RHEL-5 | RedHat | kernel-rt-0:2.6.24.7-149.el5rt | * |
| Linux | Ubuntu | jaunty | * |
| Linux | Ubuntu | karmic | * |
| Linux | Ubuntu | upstream | * |
| Linux-ec2 | Ubuntu | karmic | * |
| Linux-ec2 | Ubuntu | lucid | * |
| Linux-ec2 | Ubuntu | maverick | * |
| Linux-fsl-imx51 | Ubuntu | karmic | * |
| Linux-fsl-imx51 | Ubuntu | lucid | * |
| Linux-lts-backport-maverick | Ubuntu | lucid | * |
A race condition occurs within concurrent environments, and it is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc. A race condition violates these properties, which are closely related:
A race condition exists when an “interfering code sequence” can still access the shared resource, violating exclusivity. The interfering code sequence could be “trusted” or “untrusted.” A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.