Commit graph

18 commits

Author SHA1 Message Date
John Johansen
4eece9d5ee with unix rules we output a downgraded rule compatible with network rules
so that policy will work on kernels that support network socket controls
but not the extended af_unix rules

however this is currently broken if the socket type is left unspecified
(initialized to -1), resulting in denials for kernels that don't support
the extended af_unix rules.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: timeout
2017-09-07 02:26:15 -07:00
John Johansen
a0706d3a46 And the related patch to fix globbing for af_unix abstract names
Abstract af_unix socket names can contain a null character, however the
aare to pcre conversion explicitly disallows null characters because they
are not valid characters for pathnames. Fix this so that they type of
globbing is selectable.

this is a partial fix for

Bug: http://bugs.launchpad.net/bugs/1413410

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2015-02-12 10:19:16 -08:00
John Johansen
c2b8a72317 disable downgrade and not enforced rule messages by default
Currently the apparmor parser warns about rules that are not enforced or
downgraded. This is a problem for distros that are not carrying the out of
tree kernel patches, as most profile loads result in warnings.

Change the behavior to not output a message unless a warn flag is passed.
This patch adds 2 different warn flags
  --warn rule-downgraded    	 # warn if a rule is downgraded
  --warn rule-not-enforced	   # warn if a rule is not enforced at all

If the warnings are desired by default the flags can be set in the
parser.conf file.

v2 of patch
- update man page
- add --warn to usage statement
- make --quiet clear warn flags

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2014-10-08 13:20:20 -07:00
Tyler Hicks
a154d14f5a parser: Sync parser and man page regarding local and peer perms
This patch updates the parser code to reject rules that contain local
socket permissions and peer conditional elements. The error message for
that condition is also corrected to resolve a copy and paste mistake
from the D-Bus rule parsing code.

The patch also updates the man page to correctly describe the two sets
of socket permissions and fixes an example rule that resulted in a
parser error after the change described above.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2014-09-22 11:34:32 -05:00
John Johansen
ffa2f682ea Do not output local permissions for rules that have peer_conditionals
while it is not possible to specify a rule with local conditionals with
peer conditionals
eg.
   unix listen peer=(addr=@foo),

a rule such as
   unix peer=(addr=@foo),

is possible, and was setting all permissions for local as well as the peer
condition permissions.

Currently this means the create permission must be specified in a separate
rule from a rule with a peer= condition, if create is to be allowed. This
isn't too much of an issue but it does mean rule such as
  unix connect peer=(addr=@foo),

Can not imply the ability to create a socket. Which may indeed be the
behavior if we wish to enforce that the socket was created in another
process and passed in. Is this what we want to do?

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Tyler Hicks <tyhicks@canonical.com>
2014-09-22 11:33:49 -05:00
John Johansen
2259857281 parser: Fix the permission encoding output of getopt/setopt
Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2014-09-04 12:40:47 -07:00
John Johansen
29c776e4fc parser: fix rejecting of unix rules with listen or bind permissions
Only reject rules with explicit listen or bind permissions if a peer
conditional is specified.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-09-03 16:09:06 -07:00
John Johansen
e119901e3a parser: fix output of listen and setopts commands
The listen and setopts commands have broken encodings because the
tmp stream they use to handle diverging from the other commands
has does not set its write position to to the end of the copied data.
Instead the write head is set to the beginning so that when the
new data for the command is written it overwrites the begging of
the command instead of appending to it.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-09-03 16:04:31 -07:00
John Johansen
4a616e3545 parser: allow specifying the unix perm with peer perms
Fix to allow specifying the unix perm with peer perms. This is allowed
now and even supported, since for unix sockets the peer accept is
mediated in the unix_stream_connect hook (something that is not
possible in the lsm accept hook).

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-09-03 16:01:37 -07:00
John Johansen
4f80b4d5ca parser: change/fix the encoding for unix socket rules.
This changes/fixes the encoding for unix socket rules. The changes
look larger than they are because it refactors the code, instead
of duplicating.

The major changes are:
- it changes where the accept perm is stored
- it moves anyone_match_pattern to default_match_pattern
- it fixes the layout of the local addr only being written when local
  perms are present

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2014-09-03 15:57:17 -07:00
Tyler Hicks
0005895e3d parser: Don't write the stream's address to the rule buffer
The writeu16() function was returning the address of the passed in
std::ostringstream and then the callers of that function were
incorrectly writing that address to the rule buffer.

Before:

  $ echo "/t { unix (connect,read,write) type=stream, }" |
apparmor_parser -qQD dfa-states
  {1} <== (allow/deny/audit/quiet)
  {2} (0x 4/0/0/0)
  {3} (0x 4/0/0/0)
  {43} (0x 46/0/0/0)
  {44} (0x 46/0/0/0)
  
  {1} -> {2}: 0x2
  {1} -> {3}: 0x4
  {1} -> {2}: 0x7
  {1} -> {2}: 0x9
  {1} -> {2}: 0xa
  {1} -> {2}: 0x20 \ 
  {1} -> {4}: 0x34 4
  {3}  (0x 4/0/0/0) -> {5}: 0x0
  {4} -> {6}: 0x0
  {5} -> {7}: 0x1
  {6} -> {2}: 0x31 1
  {7} -> {8}: 0x30 0
  {8} -> {9}: 0x78 x
  {9} -> {10}: 0x37 7
  {10} -> {11}: 0x66 f
  {11} -> {12}: 0x66 f
  {12} -> {13}: 0x66 f
  {13} -> {14}: 0x31 1
  {14} -> {15}: 0x30 0
  {15} -> {16}: 0x34 4
  {16} -> {17}: 0x66 f
  {17} -> {18}: 0x33 3
  {18} -> {19}: 0x35 5
  {19} -> {20}: 0x31 1
  {20} -> {21}: 0x38 8
  {21} -> {22}: 0x0
  {22} -> {23}: 0x1
  {23} -> {24}: 0x30 0
  {24} -> {25}: 0x78 x
  {25} -> {26}: 0x37 7
  {26} -> {27}: 0x66 f
  {27} -> {28}: 0x66 f
  {28} -> {29}: 0x66 f
  {29} -> {30}: 0x31 1
  {30} -> {31}: 0x30 0
  {31} -> {32}: 0x34 4
  {32} -> {33}: 0x66 f
  {33} -> {34}: 0x33 3
  {34} -> {35}: 0x35 5
  {35} -> {36}: 0x31 1
  {36} -> {37}: 0x38 8
  {37} -> {38}: []
  {38} -> {39}: []
  {39} -> {40}: 0x0
  {39} -> {39}: []
  {40} -> {40}: 0x0
  {40} -> {41}: 0x1
  {40} -> {39}: []
  {41} -> {42}: 0x0
  {41} -> {39}: []
  {42} -> {40}: 0x0
  {42} -> {44}: 0x1
  {42} -> {43}: []
  {43}  (0x 46/0/0/0) -> {40}: 0x0
  {43}  (0x 46/0/0/0) -> {43}: []
  {44}  (0x 46/0/0/0) -> {42}: 0x0
  {44}  (0x 46/0/0/0) -> {43}: []

After:

  $ echo "/t { unix (connect,read,write) type=stream, }" |
apparmor_parser -qQD dfa-states
  {1} <== (allow/deny/audit/quiet)
  {2} (0x 4/0/0/0)
  {3} (0x 4/0/0/0)
  {15} (0x 46/0/0/0)
  {16} (0x 46/0/0/0)
  
  {1} -> {2}: 0x2
  {1} -> {3}: 0x4
  {1} -> {2}: 0x7
  {1} -> {2}: 0x9
  {1} -> {2}: 0xa
  {1} -> {2}: 0x20 \ 
  {1} -> {4}: 0x34 4
  {3}  (0x 4/0/0/0) -> {5}: 0x0
  {4} -> {6}: 0x0
  {5} -> {7}: 0x1
  {6} -> {2}: 0x31 1
  {7} -> {8}: 0x0
  {8} -> {9}: 0x1
  {9} -> {10}: []
  {10} -> {11}: []
  {11} -> {12}: 0x0
  {11} -> {11}: []
  {12} -> {12}: 0x0
  {12} -> {13}: 0x1
  {12} -> {11}: []
  {13} -> {14}: 0x0
  {13} -> {11}: []
  {14} -> {12}: 0x0
  {14} -> {16}: 0x1
  {14} -> {15}: []
  {15}  (0x 46/0/0/0) -> {12}: 0x0
  {15}  (0x 46/0/0/0) -> {15}: []
  {16}  (0x 46/0/0/0) -> {14}: 0x0
  {16}  (0x 46/0/0/0) -> {15}: []

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-09-03 15:46:39 -07:00
Tyler Hicks
b5c3ce638d parser: Adjust writeu16() to output escaped byte sequences
The writeu16() function was outputting unescaped byte sequences to the
rule buffer. That resulted the generation of in an incomplete rule if
one of those unescaped byte sequences contained 0x00.

This patch uses u8 pointers, instead of char pointers, when writing out
the big endian u16 value. More importantly, it casts the u8 values to
unsigned ints, which is what's needed to get the properly escaped byte
sequences.

Before:

  $ echo "/t { unix (connect,read,write) type=stream, }" |
apparmor_parser -qQD dfa-states
  {1} <== (allow/deny/audit/quiet)
  {2} (0x 4/0/0/0)
  {3} (0x 4/0/0/0)
  {5} (0x 46/0/0/0)
  
  {1} -> {2}: 0x2
  {1} -> {3}: 0x4
  {1} -> {2}: 0x7
  {1} -> {2}: 0x9
  {1} -> {2}: 0xa
  {1} -> {2}: 0x20 \ 
  {1} -> {4}: 0x34 4
  {3}  (0x 4/0/0/0) -> {5}: 0x0
  {4} -> {6}: 0x0
  {6} -> {2}: 0x31 1
  

After (the next patch fixes the pointer values that are being written
out):

  $ echo "/t { unix (connect,read,write) type=stream, }" |
apparmor_parser -qQD dfa-states
  {1} <== (allow/deny/audit/quiet)
  {2} (0x 4/0/0/0)
  {3} (0x 4/0/0/0)
  {43} (0x 46/0/0/0)
  {44} (0x 46/0/0/0)
  
  {1} -> {2}: 0x2
  {1} -> {3}: 0x4
  {1} -> {2}: 0x7
  {1} -> {2}: 0x9
  {1} -> {2}: 0xa
  {1} -> {2}: 0x20 \ 
  {1} -> {4}: 0x34 4
  {3}  (0x 4/0/0/0) -> {5}: 0x0
  {4} -> {6}: 0x0
  {5} -> {7}: 0x1
  {6} -> {2}: 0x31 1
  {7} -> {8}: 0x30 0
  {8} -> {9}: 0x78 x
  {9} -> {10}: 0x37 7
  {10} -> {11}: 0x66 f
  {11} -> {12}: 0x66 f
  {12} -> {13}: 0x66 f
  {13} -> {14}: 0x31 1
  {14} -> {15}: 0x30 0
  {15} -> {16}: 0x34 4
  {16} -> {17}: 0x66 f
  {17} -> {18}: 0x33 3
  {18} -> {19}: 0x35 5
  {19} -> {20}: 0x31 1
  {20} -> {21}: 0x38 8
  {21} -> {22}: 0x0
  {22} -> {23}: 0x1
  {23} -> {24}: 0x30 0
  {24} -> {25}: 0x78 x
  {25} -> {26}: 0x37 7
  {26} -> {27}: 0x66 f
  {27} -> {28}: 0x66 f
  {28} -> {29}: 0x66 f
  {29} -> {30}: 0x31 1
  {30} -> {31}: 0x30 0
  {31} -> {32}: 0x34 4
  {32} -> {33}: 0x66 f
  {33} -> {34}: 0x33 3
  {34} -> {35}: 0x35 5
  {35} -> {36}: 0x31 1
  {36} -> {37}: 0x38 8
  {37} -> {38}: []
  {38} -> {39}: []
  {39} -> {40}: 0x0
  {39} -> {39}: []
  {40} -> {40}: 0x0
  {40} -> {41}: 0x1
  {40} -> {39}: []
  {41} -> {42}: 0x0
  {41} -> {39}: []
  {42} -> {40}: 0x0
  {42} -> {44}: 0x1
  {42} -> {43}: []
  {43}  (0x 46/0/0/0) -> {40}: 0x0
  {43}  (0x 46/0/0/0) -> {43}: []
  {44}  (0x 46/0/0/0) -> {42}: 0x0
  {44}  (0x 46/0/0/0) -> {43}: []

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-09-03 15:10:41 -07:00
Steve Beattie
ab93c858d3 parser: initialize perms in unix_rule constructor
Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-09-03 15:03:05 -07:00
John Johansen
e811d8f2bf parser: map net permission set into a form compatible with the old dfa table
The old dfa table format has 2 64 bit permission field used to store
all of allow, quiet, audit, owner/!owner and transition mask. This
leaves 7 bits for entry + a few other special bits.

Since policydb entries when using old style dfa permission format
don't use support the !owner permission entries we can map, the
high net work permission bits to these entries.

This allows us to enforce base network permissions on system with
only support for the old dfa table format.

  Bits 0-7 inclusive stay put
  Bits 8-9 inclusive move (14 - 8) = 6 to 14-15 GETATTR | SETATTR
  Bits 20-22 inclusive move -4 to 16-18  ACCEPT | BIND | LISTEN  (notice 22 not 23)
  Bit 23 is skipped, hence the need to shift 5 for 24-25 instead of 4
  Bits 24-25 inclusive move -5 to 19-20

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Steve Beattie <steve@nxnw.org>
2014-09-03 14:50:22 -07:00
Steve Beattie
ade71dc171 parser: Fix segfault in af_unix rule processing
This patch fixes a segfault that was occurring in testing over the
weekend. The problem existed in the original patch that adds af_unix
rules (lp:apparmor commit 2615).

Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: John Johansen <john.johansen@canonical.com>
2014-09-03 14:08:48 -07:00
Steve Beattie
e85777a57c parser: Convert af_unix rules to support addr= rather than path=
This patch converts the path= modifier to the af_unix rules to use
addr= instead.

Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-09-03 14:02:25 -07:00
Steve Beattie
019de74059 parser: fix logic error and incorrect reference from previous commit
Signed-off-by: Steve Beattie <steve@nxnw.org>
Acked-by: John Johansen <john.johansen@canonical.com>
2014-09-03 13:34:10 -07:00
John Johansen
dd44858e60 parser: first step implementing fine grained mediation for unix domain sockets
This patch implements parsing of fine grained mediation for unix domain
sockets, that have abstract and anonymous paths. Sockets with file
system paths are handled by regular file access rules.

The unix network rules follow the general fine grained network
rule pattern of

  [<qualifiers>] af_name [<access expr>] [<rule conds>] [<local expr>] [<peer expr>]

specifically for af_unix this is

  [<qualifiers>] 'unix' [<access expr>] [<rule conds>] [<local expr>] [<peer expr>]

  <qualifiers> = [ 'audit' ] [ 'allow' | 'deny' ]

  <access expr> = ( <access> | <access list> )

  <access> = ( 'server' | 'create' | 'bind' | 'listen' | 'accept' |
               'connect' | 'shutdown' | 'getattr' | 'setattr' |
	       'getopt' | 'setopt' |
               'send' | 'receive' | 'r' | 'w' | 'rw' )
  (some access modes are incompatible with some rules or require additional
   parameters)

  <access list> = '(' <access> ( [','] <WS> <access> )* ')'

  <WS> = white space

  <rule conds> = ( <type cond> | <protocol cond> )*
     each cond can appear at most once

  <type cond> = 'type' '='  ( <AARE> | '(' ( '"' <AARE> '"' | <AARE> )+ ')' )

  <protocol cond> = 'protocol' '='  ( <AARE> | '(' ( '"' <AARE> '"' | <AARE> )+ ')' )

  <local expr> = ( <path cond> | <attr cond> | <opt cond> )*
     each cond can appear at most once

  <peer expr> = 'peer' '=' ( <path cond> | <label cond> )+
     each cond can appear at most once

  <path cond> = 'path' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')' )

  <label cond> = 'label' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')')

  <attr cond> = 'attr' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')' )

  <opt cond> = 'opt' '=' ( <AARE> | '(' '"' <AARE> '"' | <AARE> ')' )

  <AARE> = ?*[]{}^ ( see man page )

 unix domain socket rules are accumulated so that the granted unix
 socket permissions are the union of all the listed unix rule permissions.

 unix domain socket rules are broad and general and become more restrictive
 as further information is specified. Policy may be specified down to
 the path and label level. The content of the communication is not
 examined.

 Some permissions are not compatible with all unix rules.

 unix socket rule permissions are implied when a rule does not explicitly
 state an access list. By default if a rule does not have an access list
 all permissions that are compatible with the specified set of local
 and peer conditionals are implied.

 The 'server', 'r', 'w' and 'rw' permissions are aliases for other permissions.
 server = (create, bind, listen, accept)
 r = (receive, getattr, getopt)
 w = (create, connect, send, setattr, setopt)

In addition it supports the v7 kernel abi semantics around generic
network rules. The v7 abi removes the masking unix and netlink
address families from the generic masking and uses fine grained
mediation for an address type if supplied.

This means that the rules

  network unix,
  network netlink,

are now enforced instead of ignored. The parser previously could accept
these but the kernel would ignore anything written to them. If a network
rule is supplied it takes precedence over the finer grained mediation
rule. If permission is not granted via a broad network access rule
fine grained mediation is applied.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
2014-09-03 13:22:26 -07:00