CVE-2008-7256: Null Pointer Dereference

First published: Wed May 26 2010(Updated: )

Description of problem: knfsd crashes if you are using it to export shmemfs objects and run strict overcommit. In this situation the current-&gt;mm based modifier to the overcommit goes through a NULL pointer. We could simply check for NULL and skip the modifier but we've caught other real bugs in the past from mm being NULL here - cases where we did need a valid mm set up (eg the exec bug in 2005). To preserve the checks and get the logic we want shuffle the checking around and add a new helper to the vm_ security wrappers Also fix a current-&gt;mm reference in nommu that should use the passed mm Upstream commit: nfsd: fix vm overcommit crash <a href="http://git.kernel.org/linus/731572d39fcd3498702eda4600db4c43d51e0b26">http://git.kernel.org/linus/731572d39fcd3498702eda4600db4c43d51e0b26</a> nfsd: fix vm overcommit crash fix #2 <a href="http://git.kernel.org/linus/1b79cd04fab80be61dcd2732e2423aafde9a4c1c">http://git.kernel.org/linus/1b79cd04fab80be61dcd2732e2423aafde9a4c1c</a> Reference: [PATCH] knfsd: add nfs-export support to tmpfs <a href="http://git.kernel.org/linus/91828a405ae454a9503c41a7744f6ff877a80714">http://git.kernel.org/linus/91828a405ae454a9503c41a7744f6ff877a80714</a>

Credit: cve@mitre.org cve@mitre.org

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Read MoreStart Free Trial

• collector/nvd-historical
• collector/nvd-index
• collector/nvd-api
• agent/author
• agent/type
• agent/last-modified-date
• agent/softwarecombine
• agent/first-publish-date
• collector/redhat-bugzilla
• source/Red Hat
• alias/CVE-2008-7256
• agent/severity
• agent/references
• agent/weakness
• agent/event
• agent/tags
• agent/description
• collector/mitre-cve
• source/MITRE
• vendor/linux
• canonical/linux linux kernel
• version/linux linux kernel/2.6.28
• version/linux linux kernel/2.6.0
• version/linux linux kernel/2.6.1
• version/linux linux kernel/2.6.2
• version/linux linux kernel/2.6.10
• version/linux linux kernel/2.6.11
• version/linux linux kernel/2.6.11.1
• version/linux linux kernel/2.6.11.2
• version/linux linux kernel/2.6.11.3
• version/linux linux kernel/2.6.11.4
• version/linux linux kernel/2.6.11.5
• version/linux linux kernel/2.6.11.6
• version/linux linux kernel/2.6.11.7
• version/linux linux kernel/2.6.11.8
• version/linux linux kernel/2.6.11.9
• version/linux linux kernel/2.6.11.10
• version/linux linux kernel/2.6.11.11
• version/linux linux kernel/2.6.11.12
• version/linux linux kernel/2.6.12
• version/linux linux kernel/2.6.12.1
• version/linux linux kernel/2.6.12.2
• version/linux linux kernel/2.6.12.3
• version/linux linux kernel/2.6.12.4
• version/linux linux kernel/2.6.12.5
• version/linux linux kernel/2.6.12.6
• version/linux linux kernel/2.6.13
• version/linux linux kernel/2.6.13.1
• version/linux linux kernel/2.6.13.2
• version/linux linux kernel/2.6.13.3
• version/linux linux kernel/2.6.13.4
• version/linux linux kernel/2.6.13.5
• version/linux linux kernel/2.6.14
• version/linux linux kernel/2.6.14.1
• version/linux linux kernel/2.6.14.2
• version/linux linux kernel/2.6.14.3
• version/linux linux kernel/2.6.14.4
• version/linux linux kernel/2.6.14.5
• version/linux linux kernel/2.6.14.6
• version/linux linux kernel/2.6.14.7
• version/linux linux kernel/2.6.15
• version/linux linux kernel/2.6.15.1
• version/linux linux kernel/2.6.15.2
• version/linux linux kernel/2.6.15.3
• version/linux linux kernel/2.6.15.4
• version/linux linux kernel/2.6.15.5
• version/linux linux kernel/2.6.15.6
• version/linux linux kernel/2.6.15.7
• version/linux linux kernel/2.6.16
• version/linux linux kernel/2.6.16.1
• version/linux linux kernel/2.6.16.2
• version/linux linux kernel/2.6.16.3
• version/linux linux kernel/2.6.16.4
• version/linux linux kernel/2.6.16.5
• version/linux linux kernel/2.6.16.6
• version/linux linux kernel/2.6.16.7
• version/linux linux kernel/2.6.16.8
• version/linux linux kernel/2.6.16.9
• version/linux linux kernel/2.6.16.10
• version/linux linux kernel/2.6.16.11
• version/linux linux kernel/2.6.16.12
• version/linux linux kernel/2.6.16.13
• version/linux linux kernel/2.6.16.14
• version/linux linux kernel/2.6.16.15
• version/linux linux kernel/2.6.16.16
• version/linux linux kernel/2.6.16.17
• version/linux linux kernel/2.6.16.18
• version/linux linux kernel/2.6.16.19
• version/linux linux kernel/2.6.16.20
• version/linux linux kernel/2.6.16.21
• version/linux linux kernel/2.6.16.22
• version/linux linux kernel/2.6.16.23
• version/linux linux kernel/2.6.16.24
• version/linux linux kernel/2.6.16.25
• version/linux linux kernel/2.6.16.26
• version/linux linux kernel/2.6.16.27
• version/linux linux kernel/2.6.16.28
• version/linux linux kernel/2.6.16.29
• version/linux linux kernel/2.6.16.30
• version/linux linux kernel/2.6.16.31
• version/linux linux kernel/2.6.16.32
• version/linux linux kernel/2.6.16.33
• version/linux linux kernel/2.6.16.34
• version/linux linux kernel/2.6.16.35
• version/linux linux kernel/2.6.16.36
• version/linux linux kernel/2.6.16.37
• version/linux linux kernel/2.6.16.38
• version/linux linux kernel/2.6.16.39
• version/linux linux kernel/2.6.16.40
• version/linux linux kernel/2.6.16.41
• version/linux linux kernel/2.6.16.42
• version/linux linux kernel/2.6.16.43
• version/linux linux kernel/2.6.16.44
• version/linux linux kernel/2.6.16.45
• version/linux linux kernel/2.6.16.46
• version/linux linux kernel/2.6.16.47
• version/linux linux kernel/2.6.16.48
• version/linux linux kernel/2.6.16.49
• version/linux linux kernel/2.6.16.50
• version/linux linux kernel/2.6.16.51
• version/linux linux kernel/2.6.16.52
• version/linux linux kernel/2.6.16.53
• version/linux linux kernel/2.6.16.54
• version/linux linux kernel/2.6.16.55
• version/linux linux kernel/2.6.16.56
• version/linux linux kernel/2.6.16.57
• version/linux linux kernel/2.6.16.58
• version/linux linux kernel/2.6.16.59
• version/linux linux kernel/2.6.16.60
• version/linux linux kernel/2.6.16.61
• version/linux linux kernel/2.6.16.62
• version/linux linux kernel/2.6.17
• version/linux linux kernel/2.6.17.1
• version/linux linux kernel/2.6.17.2
• version/linux linux kernel/2.6.17.3
• version/linux linux kernel/2.6.17.4
• version/linux linux kernel/2.6.17.5
• version/linux linux kernel/2.6.17.6
• version/linux linux kernel/2.6.17.7
• version/linux linux kernel/2.6.17.8
• version/linux linux kernel/2.6.17.9
• version/linux linux kernel/2.6.17.10
• version/linux linux kernel/2.6.17.11
• version/linux linux kernel/2.6.17.12
• version/linux linux kernel/2.6.17.13
• version/linux linux kernel/2.6.17.14
• version/linux linux kernel/2.6.18
• version/linux linux kernel/2.6.18.1
• version/linux linux kernel/2.6.18.2
• version/linux linux kernel/2.6.18.3
• version/linux linux kernel/2.6.18.4
• version/linux linux kernel/2.6.18.5
• version/linux linux kernel/2.6.18.6
• version/linux linux kernel/2.6.18.7
• version/linux linux kernel/2.6.18.8
• version/linux linux kernel/2.6.19
• version/linux linux kernel/2.6.19.1
• version/linux linux kernel/2.6.19.2
• version/linux linux kernel/2.6.19.3
• version/linux linux kernel/2.6.19.4
• version/linux linux kernel/2.6.19.5
• version/linux linux kernel/2.6.19.6
• version/linux linux kernel/2.6.19.7
• version/linux linux kernel/2.6.20
• version/linux linux kernel/2.6.20.1
• version/linux linux kernel/2.6.20.2
• version/linux linux kernel/2.6.20.3
• version/linux linux kernel/2.6.20.4
• version/linux linux kernel/2.6.20.5
• version/linux linux kernel/2.6.20.6
• version/linux linux kernel/2.6.20.7
• version/linux linux kernel/2.6.20.8
• version/linux linux kernel/2.6.20.9
• version/linux linux kernel/2.6.20.10
• version/linux linux kernel/2.6.20.11
• version/linux linux kernel/2.6.20.12
• version/linux linux kernel/2.6.20.13
• version/linux linux kernel/2.6.20.14
• version/linux linux kernel/2.6.20.15
• version/linux linux kernel/2.6.20.16
• version/linux linux kernel/2.6.20.17
• version/linux linux kernel/2.6.20.18
• version/linux linux kernel/2.6.20.19
• version/linux linux kernel/2.6.20.20
• version/linux linux kernel/2.6.20.21
• version/linux linux kernel/2.6.21
• version/linux linux kernel/2.6.21.1
• version/linux linux kernel/2.6.21.2
• version/linux linux kernel/2.6.21.3
• version/linux linux kernel/2.6.21.4
• version/linux linux kernel/2.6.21.5
• version/linux linux kernel/2.6.21.6
• version/linux linux kernel/2.6.21.7
• version/linux linux kernel/2.6.22
• version/linux linux kernel/2.6.22.1
• version/linux linux kernel/2.6.22.2
• version/linux linux kernel/2.6.22.3
• version/linux linux kernel/2.6.22.4
• version/linux linux kernel/2.6.22.5
• version/linux linux kernel/2.6.22.6
• version/linux linux kernel/2.6.22.7
• version/linux linux kernel/2.6.22.8
• version/linux linux kernel/2.6.22.9
• version/linux linux kernel/2.6.22.10
• version/linux linux kernel/2.6.22.11
• version/linux linux kernel/2.6.22.12
• version/linux linux kernel/2.6.22.13
• version/linux linux kernel/2.6.22.14
• version/linux linux kernel/2.6.22.15
• version/linux linux kernel/2.6.22.16
• version/linux linux kernel/2.6.22.17
• version/linux linux kernel/2.6.22.18
• version/linux linux kernel/2.6.22.19
• version/linux linux kernel/2.6.22.20
• version/linux linux kernel/2.6.22.21
• version/linux linux kernel/2.6.22.22
• version/linux linux kernel/2.6.23
• version/linux linux kernel/2.6.23.1
• version/linux linux kernel/2.6.23.2
• version/linux linux kernel/2.6.23.3
• version/linux linux kernel/2.6.23.4
• version/linux linux kernel/2.6.23.5
• version/linux linux kernel/2.6.23.6
• version/linux linux kernel/2.6.23.7
• version/linux linux kernel/2.6.23.8
• version/linux linux kernel/2.6.23.9
• version/linux linux kernel/2.6.23.10
• version/linux linux kernel/2.6.23.11
• version/linux linux kernel/2.6.23.12
• version/linux linux kernel/2.6.23.13
• version/linux linux kernel/2.6.23.14
• version/linux linux kernel/2.6.23.15
• version/linux linux kernel/2.6.23.16
• version/linux linux kernel/2.6.23.17
• version/linux linux kernel/2.6.24
• version/linux linux kernel/2.6.24.1
• version/linux linux kernel/2.6.24.2
• version/linux linux kernel/2.6.24.3
• version/linux linux kernel/2.6.24.4
• version/linux linux kernel/2.6.24.5
• version/linux linux kernel/2.6.24.6
• version/linux linux kernel/2.6.24.7
• version/linux linux kernel/2.6.25
• version/linux linux kernel/2.6.25.1
• version/linux linux kernel/2.6.25.2
• version/linux linux kernel/2.6.25.3
• version/linux linux kernel/2.6.25.4
• version/linux linux kernel/2.6.25.5
• version/linux linux kernel/2.6.25.6
• version/linux linux kernel/2.6.25.7
• version/linux linux kernel/2.6.25.8
• version/linux linux kernel/2.6.25.9
• version/linux linux kernel/2.6.25.10
• version/linux linux kernel/2.6.25.11
• version/linux linux kernel/2.6.25.12
• version/linux linux kernel/2.6.25.13
• version/linux linux kernel/2.6.25.14
• version/linux linux kernel/2.6.25.15
• version/linux linux kernel/2.6.25.16
• version/linux linux kernel/2.6.25.17
• version/linux linux kernel/2.6.25.18
• version/linux linux kernel/2.6.25.19
• version/linux linux kernel/2.6.25.20
• version/linux linux kernel/2.6.27
• version/linux linux kernel/2.6.27-rc1
• version/linux linux kernel/2.6.27-rc2
• version/linux linux kernel/2.6.27-rc3
• version/linux linux kernel/2.6.27-rc4
• version/linux linux kernel/2.6.27-rc5
• version/linux linux kernel/2.6.27-rc6
• version/linux linux kernel/2.6.27-rc7
• version/linux linux kernel/2.6.27-rc8
• version/linux linux kernel/2.6.27-rc9
• version/linux linux kernel/2.6.27.1
• version/linux linux kernel/2.6.27.2
• version/linux linux kernel/2.6.27.3
• version/linux linux kernel/2.6.27.4
• version/linux linux kernel/2.6.27.5
• version/linux linux kernel/2.6.27.6
• version/linux linux kernel/2.6.27.7
• version/linux linux kernel/2.6.27.8
• version/linux linux kernel/2.6.27.9
• version/linux linux kernel/2.6.27.10
• version/linux linux kernel/2.6.27.11
• version/linux linux kernel/2.6.27.12
• version/linux linux kernel/2.6.27.13
• version/linux linux kernel/2.6.27.14
• version/linux linux kernel/2.6.27.15
• version/linux linux kernel/2.6.27.16
• version/linux linux kernel/2.6.27.17
• version/linux linux kernel/2.6.27.18
• version/linux linux kernel/2.6.27.19
• version/linux linux kernel/2.6.27.20
• version/linux linux kernel/2.6.27.21
• version/linux linux kernel/2.6.27.22
• version/linux linux kernel/2.6.27.23
• version/linux linux kernel/2.6.27.24
• version/linux linux kernel/2.6.27.25
• version/linux linux kernel/2.6.27.26
• version/linux linux kernel/2.6.27.27
• version/linux linux kernel/2.6.27.28
• version/linux linux kernel/2.6.27.29
• version/linux linux kernel/2.6.27.30
• version/linux linux kernel/2.6.27.31
• version/linux linux kernel/2.6.27.32
• version/linux linux kernel/2.6.27.33
• version/linux linux kernel/2.6.27.34
• version/linux linux kernel/2.6.27.35
• version/linux linux kernel/2.6.27.36
• version/linux linux kernel/2.6.27.37
• version/linux linux kernel/2.6.27.38
• version/linux linux kernel/2.6.27.39
• version/linux linux kernel/2.6.27.40
• version/linux linux kernel/2.6.27.41
• version/linux linux kernel/2.6.27.42
• version/linux linux kernel/2.6.27.43
• version/linux linux kernel/2.6.27.44
• version/linux linux kernel/2.6.27.45
• version/linux linux kernel/2.6.28-rc1
• version/linux linux kernel/2.6.28-rc2
• version/linux linux kernel/2.6.28-rc3
• version/linux linux kernel/2.6.28-rc4
• version/linux linux kernel/2.6.28-rc5
• version/linux linux kernel/2.6.28-rc6