45 lines
1.6 KiB
Diff
45 lines
1.6 KiB
Diff
From: "Eric W. Biederman" <ebiederm@xmission.com>
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Date: Wed, 7 Jan 2015 14:28:26 -0600
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Subject: mnt: Fail collect_mounts when applied to unmounted mounts
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Origin: https://git.kernel.org/linus/cd4a40174b71acd021877341684d8bb1dc8ea4ae
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The only users of collect_mounts are in audit_tree.c
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In audit_trim_trees and audit_add_tree_rule the path passed into
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collect_mounts is generated from kern_path passed an audit_tree
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pathname which is guaranteed to be an absolute path. In those cases
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collect_mounts is obviously intended to work on mounted paths and
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if a race results in paths that are unmounted when collect_mounts
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it is reasonable to fail early.
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The paths passed into audit_tag_tree don't have the absolute path
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check. But are used to play with fsnotify and otherwise interact with
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the audit_trees, so again operating only on mounted paths appears
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reasonable.
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Avoid having to worry about what happens when we try and audit
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unmounted filesystems by restricting collect_mounts to mounts
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that appear in the mount tree.
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Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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---
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fs/namespace.c | 7 +++++--
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1 file changed, 5 insertions(+), 2 deletions(-)
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--- a/fs/namespace.c
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+++ b/fs/namespace.c
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@@ -1709,8 +1709,11 @@ struct vfsmount *collect_mounts(struct p
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{
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struct mount *tree;
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namespace_lock();
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- tree = copy_tree(real_mount(path->mnt), path->dentry,
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- CL_COPY_ALL | CL_PRIVATE);
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+ if (!check_mnt(real_mount(path->mnt)))
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+ tree = ERR_PTR(-EINVAL);
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+ else
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+ tree = copy_tree(real_mount(path->mnt), path->dentry,
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+ CL_COPY_ALL | CL_PRIVATE);
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namespace_unlock();
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if (IS_ERR(tree))
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return ERR_CAST(tree);
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