Gentoo Archives: gentoo-hardened

From: brant williams <brant@×××××.net>
To: gentoo-hardened@l.g.o
Subject: Re: [gentoo-hardened] Grsecurity: Role flag "G" problem
Date: Sun, 23 Nov 2008 22:47:21
Message-Id: Pine.LNX.4.64.0811231641190.9927@beaker.tnarb.net
In Reply to: Re: [gentoo-hardened] Grsecurity: Role flag "G" problem by brant williams
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2 Hash: SHA256
3
4 Hello again...
5
6 I just re-read your original message and am still not entirely sure what
7 you're trying to do here. If you _want_ to have directories like /boot
8 and /root hidden from the root role/user via RBAC, then you should
9 probably hide/suppress ("hs") them in the "subject" section for bash,
10 which is what is calling `gradm`.
11
12 I'm not entirely sure, but you may need to add these flags to the subject
13 for /sbin/gradm as well as /bin/bash (in root's role).
14
15 As far as there being an instance already running, are you perhaps trying
16 to run gradm in learning mode while the RBAC system is already active?
17
18 Hrm...
19
20 brant williams
21 FCAA CDCA 20BC 3925 D634 F5C4 7420 6784 4DEB 6002
22
23
24
25 On Sun, 23 Nov 2008, brant williams wrote:
26
27 > Date: Sun, 23 Nov 2008 16:38:16 -0600 (CST)
28 > From: brant williams <brant@×××××.net>
29 > Reply-To: gentoo-hardened@l.g.o
30 > To: gentoo-hardened@l.g.o
31 > Subject: Re: [gentoo-hardened] Grsecurity: Role flag "G" problem
32 >
33 > --[PinePGP]--------------------------------------------------[begin]--
34 >
35 > Why would you specify "hs" for /root in the root policy? The "h" flag
36 > will hide that path from the role. You probably want something like:
37 >
38 > role root uG
39 > subject / {
40 > / r
41 > #
42 > # (other filesystem paths and permissions here)
43 > #
44 > /root r
45 > # capabilities, etc, here
46 > -CAP_ALL
47 > bind disabled
48 > connect disabled
49 > }
50 >
51 > Replacing the object flag "h" with "hs" will still hide things. ;) In
52 > the same way, changing from "x" to "rx" will still not allow you to write
53 > to the file.
54 >
55 > You might want to take a look at this[1] link...
56 >
57 > [1] http://www.grsecurity.net/wiki/index.php/GrsecurityRBACObjModes
58 >
59 > Hope that helps...
60 >
61 >
62 > brant williams
63 > FCAA CDCA 20BC 3925 D634 F5C4 7420 6784 4DEB 6002
64 >
65 >
66 >
67 > On Sun, 23 Nov 2008, atoth@××××××××××.hu wrote:
68 >
69 >> Date: Sun, 23 Nov 2008 10:48:51 +0100 (CET)
70 >> From: atoth@××××××××××.hu
71 >> Reply-To: gentoo-hardened@l.g.o
72 >> To: gentoo-hardened@l.g.o
73 >> Subject: [gentoo-hardened] Grsecurity: Role flag "G" problem
74 >>
75 >> Since I've upgraded to a kernel based on 2.6.27 (2.6.27-hardened-r1), some
76 >> error messages are logged every time I authenticate myself as root.
77 >> "
78 >> Nov 23 10:09:44 hostname grsec: (root:U:/sbin/gradm) denied access to
79 >> hidden file /root by /sbin/gradm[gradm:7187] uid/euid:0/0 gid/egid:0/0,
80 >> parent /bin/bash[bash:7033] uid/euid:0/0 gid/egid:0/0
81 >> "
82 >> Role flag "G" is specified for root in order to make this user able to
83 >> authenticate using gradm. Some directories - including boot - are hidden.
84 >> No matter if I replace "h" to "hs" for role root, these messages still get
85 >> logged. If I try to create a policy for gradm, grsec reports, that I've
86 >> tried to modify an already existing instance - which is probably included
87 >> because Role flag "G", but the exact contents are hidden.
88 >> This behavior appeared recently.
89 >>
90 >> Did I miss something?
91 >> Any ideas on this are greatly appreciated.
92 >>
93 >> Is it discouraged to authenticate using gradm while logged in as root?
94 >>
95 >> Regards,
96 >> Dw.
97 >> --
98 >> dr Tóth Attila, Radiológus Szakorvos jelölt, 06-20-825-8057,
99 >> 06-30-5962-962
100 >> Attila Toth MD, Radiologist in Training, +36-20-825-8057, +36-30-5962-962
101 >>
102 >>
103 >>
104 > --[PinePGP]-----------------------------------------------------------
105 > gpg: Signature made Sun Nov 23 16:38:22 2008 CST using DSA key ID 4DEB6002
106 > gpg: Good signature from "brant davin williams (never say anything)
107 > gpg: <brant@×××××.net>"
108 > --[PinePGP]----------------------------------------------------[end]--
109 >
110 >
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115 xnMAnRhJphRycWvttBsCSJAOyUhsY2Dj
116 =Wzhk
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Replies

Subject Author
Re: [gentoo-hardened] Grsecurity: Role flag "G" problem atoth@××××××××××.hu