oss-sec mailing list archives
CVE request -- Linux kernel: call_console_drivers() Function Log Prefix Stripping buffer overflow
From: Petr Matousek <pmatouse () redhat com>
Date: Tue, 26 Feb 2013 12:39:05 +0100
A buffer overflow flaw was found in kernels from 3.0 to 3.4 when calling log_prefix() function from call_console_drivers(). This bug existed in previous releases but has been revealed with commit 162a7e7500f9664636e649ba59defe541b7c2c60 (2.6.39 => 3.0) that made changes about how to allocate memory for early printk buffer (use of memblock_alloc). It disappears with commit 7ff9554bb578ba02166071d2d487b7fc7d860d62 (3.4 => 3.5) that does a refactoring of printk buffer management. In log_prefix(), the access to "p[0]", "p[1]", "p[2]" or "simple_strtoul(&p[1], &endp, 10)" may cause a buffer overflow as this function is called from call_console_drivers by passing "&LOG_BUF(cur_index)" where the index must be masked to do not exceed the buffer's boundary. Note: /dev/kmsg is root writable only (at least on RHEL/Fedora), but it still might cause issues in restricted root environments. References: https://bugs.gentoo.org/458780 https://secunia.com/advisories/52366/ Thanks, -- Petr Matousek / Red Hat Security Response Team
Current thread:
- CVE request -- Linux kernel: call_console_drivers() Function Log Prefix Stripping buffer overflow Petr Matousek (Feb 26)