On 05/12/2014 06:24 AM, Tetsuo Handa wrote:
>>From 819e94ae3a6d9235196d137a39afa4e0bbd79770 Mon Sep 17 00:00:00 2001
> From: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
> Date: Mon, 12 May 2014 21:54:05 +0900
> Subject: [PATCH (for 3.15) 3/5] AppArmor: Handle the rename flags.
>
> For AppArmor, the RENAME_EXCHANGE flag means "check permissions with
> reversed arguments" and "distinguish condition of source and target".
> Future patches will stop re-calculating pathnames.
>
> Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
This isn't quite right. For apparmor at this point these paths need to
be still treated like they are separate. The second aa_path_perm, is
checking the permission to move old_inode to new_path.
see below
I've added an updated patch below
> ---
> security/apparmor/lsm.c | 22 ++++++++++++++++++++--
> 1 files changed, 20 insertions(+), 2 deletions(-)
>
> diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
> index c0b4366..9f21296 100644
> --- a/security/apparmor/lsm.c
> +++ b/security/apparmor/lsm.c
> @@ -331,7 +331,14 @@ static int apparmor_path_rename(struct path *old_dir,
> struct dentry *old_dentry,
> struct path_cond cond = { old_dentry->d_inode->i_uid,
> old_dentry->d_inode->i_mode
> };
> + struct path_cond new_cond = cond;
>
> + if (flags & RENAME_EXCHANGE) {
> + /* Cross rename requires both inodes to exist. */
> + new_cond.uid = new_dentry->d_inode->i_uid;
> + new_cond.mode = new_dentry->d_inode->i_mode;
> + }
> +retry:
> error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
> MAY_READ | AA_MAY_META_READ | MAY_WRITE |
> AA_MAY_META_WRITE | AA_MAY_DELETE,
> @@ -339,7 +346,18 @@ static int apparmor_path_rename(struct path *old_dir,
> struct dentry *old_dentry,
> if (!error)
> error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
> 0, MAY_WRITE | AA_MAY_META_WRITE |
> - AA_MAY_CREATE, &cond);
> + AA_MAY_CREATE, &new_cond);
This isn't new_cond because its the permission to move old_inode to new_path
> + if (!error && (flags & RENAME_EXCHANGE)) {
> + struct path tmp_path = new_path;
> + struct path_cond tmp_cond = new_cond;
> +
> + new_path = old_path;
> + old_path = tmp_path;
> + new_cond = cond;
> + cond = tmp_cond;
> + flags = 0;
> + goto retry;
> + }
>
> }
> return error;
>
>From c07677ce007bbb5689b82bce0fab15a159f59874 Mon Sep 17 00:00:00 2001
From: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
Date: Mon, 12 May 2014 21:54:05 +0900
Subject: [PATCH] AppArmor: Handle the rename flags.
For AppArmor, the RENAME_EXCHANGE flag means "check permissions with
reversed arguments" and "distinguish condition of source and target".
Future patches will stop re-calculating pathnames.
Signed-off-by: Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp>
Signed-off-by: John Johansen <john.johan...@canonical.com>
---
security/apparmor/lsm.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index c0b4366..d7d92ad 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -332,6 +332,7 @@ static int apparmor_path_rename(struct path *old_dir,
struct dentry *old_dentry,
old_dentry->d_inode->i_mode
};
+retry:
error = aa_path_perm(OP_RENAME_SRC, profile, &old_path, 0,
MAY_READ | AA_MAY_META_READ | MAY_WRITE |
AA_MAY_META_WRITE | AA_MAY_DELETE,
@@ -340,6 +341,16 @@ static int apparmor_path_rename(struct path *old_dir,
struct dentry *old_dentry,
error = aa_path_perm(OP_RENAME_DEST, profile, &new_path,
0, MAY_WRITE | AA_MAY_META_WRITE |
AA_MAY_CREATE, &cond);
+ if (!error && (flags & RENAME_EXCHANGE)) {
+ struct path tmp_path = new_path;
+ new_path = old_path;
+ old_path = tmp_path;
+ /* Cross rename requires both inodes to exist. */
+ cond.uid = new_dentry->d_inode->i_uid;
+ cond.mode = new_dentry->d_inode->i_mode;
+ flags = 0;
+ goto retry;
+ }
}
return error;
--
2.0.0.rc0
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