Paul Starzetz and Wojciech Purczynski of isec.pl discovered a critical security vulnerability in the memory management code of Linux inside the mremap(2) system call. Due to flushing the TLB (Translation Lookaside Buffer, an address cache) too early it is possible for an attacker to trigger a local root exploit. The attack vectors for 2.4.x and 2.2.x kernels are exclusive for the respective kernel series, though. We formerly believed that the exploitable vulnerability in 2.4.x does not exist in 2.2.x which is still true. However, it turned out that a second (sort of) vulnerability is indeed exploitable in 2.2.x, but not in 2.4.x, with a different exploit, of course. For the stable distribution (woody) these problems have been fixed in version 9woody1 of Linux 2.2 kernel images for the sparc architecture and in version 2.2.20-5woody3 of Linux 2.2.20 source. For the unstable distribution (sid) these problems have been fixed in version 9.1 of Linux 2.2 kernel images for the sparc architecture. This problem has been fixed for other architectures already. We recommend that you upgrade your Linux kernel package.
Paul Starzetz and Wojciech Purczynski of isec.pl discovered a critical security vulnerability in the memory management code of Linux inside the mremap(2) system call. Due to flushing the TLB (Translation Lookaside Buffer, an address cache) too early it is possible for an attacker to trigger a local root exploit.
The attack vectors for 2.4.x and 2.2.x kernels are exclusive for the respective kernel series, though. We formerly believed that the exploitable vulnerability in 2.4.x does not exist in 2.2.x which is still true. However, it turned out that a second (sort of) vulnerability is indeed exploitable in 2.2.x, but not in 2.4.x, with a different exploit, of course.
For the stable distribution (woody) these problems have been fixed in version 9woody1 of Linux 2.2 kernel images for the sparc architecture and in version 2.2.20-5woody3 of Linux 2.2.20 source.
For the unstable distribution (sid) these problems have been fixed in version 9.1 of Linux 2.2 kernel images for the sparc architecture.
This problem has been fixed for other architectures already.
We recommend that you upgrade your Linux kernel package.
MD5 checksums of the listed files are available in the original advisory.
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