Messages in this thread | | | Subject | Re: [PATCH 00/23] Removal of binary sysctl support | From | (Eric W. Biederman) | Date | Thu, 19 Nov 2009 14:22:53 -0800 |
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Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> writes:
> Hello. > > Eric W. Biederman wrote: >> > Indeed. TOMOYO and AppArmor need a hint for prepending "/proc" prefix. >> > A simple implementation which adds one bit to task_struct is shown below. >> > In this way, not only the file permission checks inside dentry_open() >> > but also the directory permission checks inside vfs_path_lookup() can be >> > prepended "/proc" prefix. AppArmor might want to prepend "/proc" inside >> > vfs_path_lookup(). >> >> There don't appear to be any security hooks in vfs_path_lookup(). >> > OK. Then, AppArmor won't be confused. > >> Instead of current->in_sysctl we can just look at the path and see if >> it is the root of the mount chain and if the fs is proc. >> >> Something like: >> >> diff --git a/security/tomoyo/realpath.c b/security/tomoyo/realpath.c >> index 5f2e332..0b55faa 100644 >> --- a/security/tomoyo/realpath.c >> +++ b/security/tomoyo/realpath.c >> @@ -108,6 +108,15 @@ int tomoyo_realpath_from_path2(struct path *path, char *newname, >> spin_unlock(&dcache_lock); >> path_put(&root); >> path_put(&ns_root); >> + /* Prepend "/proc" prefix if using internal proc vfs mount. */ >> + if (!IS_ERR(sp) && (path->mnt->mnt_parent == path->mnt) && >> + (strcmp(path->mnt->mnt_sb->s_type->name, "proc") == 0)) { >> + sp -= 5; >> + if (sp >= newname) >> + memcpy(sp, "/proc", 5); >> + else >> + sp = ERR_PTR(-ENOMEM); >> + } >> } >> if (IS_ERR(sp)) >> error = PTR_ERR(sp); > > Above patch works. Please proceed. Thank you. > > Acked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> > > Why not to use path->mnt->mnt_sb->s_magic == PROC_SUPER_MAGIC rather than > strcmp(path->mnt->mnt_sb->s_type->name, "proc") == 0 ?
Brain short circuit.
Eric
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