News
Vigil@nce - Linux kernel: denial of service via ext4_ext_get_blocks
August 2010 by Vigil@nce
This bulletin was written by Vigil@nce : http://vigilance.fr/
SYNTHESIS OF THE VULNERABILITY
An attacker can write to the last block of a file of maximum size (16Tio) in order to stop the ext4 driver.
Severity: 1/4
Creation date: 17/08/2010
DESCRIPTION OF THE VULNERABILITY
The ext4_ext_get_blocks() of the fs/ext4/extents.c file allocates memory blocks for ext4 filesystem.
When the last bloc of a file with maximum size is allocated, a integer overflaw happen in ext4_ext_get_blocks() function. The BUG() macro is then called.
An attacker can therefore write to the last block of a file of maximum size (16Tio) in order to stop the ext4 driver.
ACCESS TO THE COMPLETE VIGIL@NCE BULLETIN
GOLD SPONSOR
