From cd51ec36f940d713057d7727ba0862f5503545f4 Mon Sep 17 00:00:00 2001 From: Sona Sarmadi Date: Mon, 8 Feb 2016 14:31:14 +0100 Subject: kernel-mnt: CVE-2015-4177 Fixes race conditions in collect_mounts References: http://seclists.org/oss-sec/2015/q2/640 https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2015-4177 Upstream patch: https://git.kernel.org/cgit/linux/kernel/git/stable/linux-stable.git/ patch/?id=6ab282fe6d43027b3b1ef820b3798aae8fdb432b Signed-off-by: Sona Sarmadi --- recipes-kernel/linux/files/mnt-CVE-2015-4177.patch | 56 ++++++++++++++++++++++ recipes-kernel/linux/linux-qoriq_3.12.bb | 1 + 2 files changed, 57 insertions(+) create mode 100644 recipes-kernel/linux/files/mnt-CVE-2015-4177.patch diff --git a/recipes-kernel/linux/files/mnt-CVE-2015-4177.patch b/recipes-kernel/linux/files/mnt-CVE-2015-4177.patch new file mode 100644 index 0000000..c6ca4bf --- /dev/null +++ b/recipes-kernel/linux/files/mnt-CVE-2015-4177.patch @@ -0,0 +1,56 @@ +From 6ab282fe6d43027b3b1ef820b3798aae8fdb432b Mon Sep 17 00:00:00 2001 +From: "Eric W. Biederman" +Date: Wed, 7 Jan 2015 14:28:26 -0600 +Subject: mnt: Fail collect_mounts when applied to unmounted mounts + +commit cd4a40174b71acd021877341684d8bb1dc8ea4ae upstream. + +The only users of collect_mounts are in audit_tree.c + +In audit_trim_trees and audit_add_tree_rule the path passed into +collect_mounts is generated from kern_path passed an audit_tree +pathname which is guaranteed to be an absolute path. In those cases +collect_mounts is obviously intended to work on mounted paths and +if a race results in paths that are unmounted when collect_mounts +it is reasonable to fail early. + +The paths passed into audit_tag_tree don't have the absolute path +check. But are used to play with fsnotify and otherwise interact with +the audit_trees, so again operating only on mounted paths appears +reasonable. + +Avoid having to worry about what happens when we try and audit +unmounted filesystems by restricting collect_mounts to mounts +that appear in the mount tree. + +Fixes CVE-2015-4177. +Upstream-Status: Backport + +Signed-off-by: "Eric W. Biederman" +Signed-off-by: Jiri Slaby +Signed-off-by: Sona Sarmadi +--- + fs/namespace.c | 7 +++++-- + 1 file changed, 5 insertions(+), 2 deletions(-) + +diff --git a/fs/namespace.c b/fs/namespace.c +index 247f34d..185cd1a 100644 +--- a/fs/namespace.c ++++ b/fs/namespace.c +@@ -1467,8 +1467,11 @@ struct vfsmount *collect_mounts(struct path *path) + { + struct mount *tree; + namespace_lock(); +- tree = copy_tree(real_mount(path->mnt), path->dentry, +- CL_COPY_ALL | CL_PRIVATE); ++ if (!check_mnt(real_mount(path->mnt))) ++ tree = ERR_PTR(-EINVAL); ++ else ++ tree = copy_tree(real_mount(path->mnt), path->dentry, ++ CL_COPY_ALL | CL_PRIVATE); + namespace_unlock(); + if (IS_ERR(tree)) + return ERR_CAST(tree); +-- +cgit v0.11.2 + diff --git a/recipes-kernel/linux/linux-qoriq_3.12.bb b/recipes-kernel/linux/linux-qoriq_3.12.bb index bcf2930..9c1da76 100644 --- a/recipes-kernel/linux/linux-qoriq_3.12.bb +++ b/recipes-kernel/linux/linux-qoriq_3.12.bb @@ -36,6 +36,7 @@ SRC_URI = "git://git.freescale.com/ppc/sdk/linux.git;nobranch=1 \ file://net-CVE-2015-2041.patch \ file://media-CVE-2014-1739.patch \ file://fs-userns-CVE-2014-4014.patch \ + file://mnt-CVE-2015-4177.patch \ " SRCREV = "6619b8b55796cdf0cec04b66a71288edd3057229" -- cgit v1.2.3-54-g00ecf