Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
apparmor: make str table more generic and be able to have multiple entries
The strtable is currently limited to a single entry string on unpack
even though domain has the concept of multiple entries within it. Make
this a reality as it will be used for tags and more advanced domain
transitions.
Reviewed-by: Georgia Garcia <georgia.garcia@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
+91
-47
+1
-1
security/apparmor/domain.c
+1
-1
security/apparmor/domain.c
···
529
529
/* TODO: move lookup parsing to unpack time so this is a straight
530
530
* index into the resultant label
531
531
*/
532
-
for (next = rules->file->trans.table[index]; next;
532
+
for (next = rules->file->trans.table[index].strs; next;
533
533
next = next_name(xtype, next)) {
534
534
const char *lookup = (*next == '&') ? next + 1 : next;
535
535
*name = next;
+10
-3
security/apparmor/include/lib.h
+10
-3
security/apparmor/include/lib.h
···
30
30
#define DEBUG_DOMAIN 4
31
31
#define DEBUG_POLICY 8
32
32
#define DEBUG_INTERFACE 0x10
33
+
#define DEBUG_UNPACK 0x40
33
34
34
35
#define DEBUG_ALL 0x1f /* update if new DEBUG_X added */
35
36
#define DEBUG_PARSE_ERROR (-1)
···
120
119
return !(dentry->d_sb->s_flags & SB_NOUSER);
121
120
}
122
121
123
-
struct aa_str_table {
122
+
struct aa_str_table_ent {
123
+
int count;
124
124
int size;
125
-
char **table;
125
+
char *strs;
126
126
};
127
127
128
-
void aa_free_str_table(struct aa_str_table *table);
128
+
struct aa_str_table {
129
+
int size;
130
+
struct aa_str_table_ent *table;
131
+
};
132
+
129
133
bool aa_resize_str_table(struct aa_str_table *t, int newsize, gfp_t gfp);
134
+
void aa_destroy_str_table(struct aa_str_table *table);
130
135
131
136
struct counted_str {
132
137
struct kref count;
+6
-5
security/apparmor/lib.c
+6
-5
security/apparmor/lib.c
···
44
44
{ "domain", DEBUG_DOMAIN },
45
45
{ "policy", DEBUG_POLICY },
46
46
{ "interface", DEBUG_INTERFACE },
47
+
{ "unpack", DEBUG_UNPACK },
47
48
{ NULL, 0 }
48
49
};
49
50
···
119
118
120
119
bool aa_resize_str_table(struct aa_str_table *t, int newsize, gfp_t gfp)
121
120
{
122
-
char **n;
121
+
struct aa_str_table_ent *n;
123
122
int i;
124
123
125
124
if (t->size == newsize)
···
130
129
for (i = 0; i < min(t->size, newsize); i++)
131
130
n[i] = t->table[i];
132
131
for (; i < t->size; i++)
133
-
kfree_sensitive(t->table[i]);
132
+
kfree_sensitive(t->table[i].strs);
134
133
if (newsize > t->size)
135
134
memset(&n[t->size], 0, (newsize-t->size)*sizeof(*n));
136
135
kfree_sensitive(t->table);
···
141
140
}
142
141
143
142
/**
144
-
* aa_free_str_table - free entries str table
143
+
* aa_destroy_str_table - free entries str table
145
144
* @t: the string table to free (MAYBE NULL)
146
145
*/
147
-
void aa_free_str_table(struct aa_str_table *t)
146
+
void aa_destroy_str_table(struct aa_str_table *t)
148
147
{
149
148
int i;
150
149
···
153
152
return;
154
153
155
154
for (i = 0; i < t->size; i++)
156
-
kfree_sensitive(t->table[i]);
155
+
kfree_sensitive(t->table[i].strs);
157
156
kfree_sensitive(t->table);
158
157
t->table = NULL;
159
158
t->size = 0;
+1
-1
security/apparmor/policy.c
+1
-1
security/apparmor/policy.c
+73
-37
security/apparmor/policy_unpack.c
+73
-37
security/apparmor/policy_unpack.c
···
450
450
return dfa;
451
451
}
452
452
453
+
static int process_strs_entry(char *str, int size, bool multi)
454
+
{
455
+
int c = 1;
456
+
457
+
if (size <= 0)
458
+
return -1;
459
+
if (multi) {
460
+
if (size < 2)
461
+
return -2;
462
+
/* multi ends with double \0 */
463
+
if (str[size - 2])
464
+
return -3;
465
+
}
466
+
467
+
char *save = str;
468
+
char *pos = str;
469
+
char *end = multi ? str + size - 2 : str + size - 1;
470
+
/* count # of internal \0 */
471
+
while (str < end) {
472
+
if (str == pos) {
473
+
/* starts with ... */
474
+
if (!*str) {
475
+
AA_DEBUG(DEBUG_UNPACK,
476
+
"starting with null save=%lu size %d c=%d",
477
+
str - save, size, c);
478
+
return -4;
479
+
}
480
+
if (isspace(*str))
481
+
return -5;
482
+
if (*str == ':') {
483
+
/* :ns_str\0str\0
484
+
* first character after : must be valid
485
+
*/
486
+
if (!str[1])
487
+
return -6;
488
+
}
489
+
} else if (!*str) {
490
+
if (*pos == ':')
491
+
*str = ':';
492
+
else
493
+
c++;
494
+
pos = str + 1;
495
+
}
496
+
str++;
497
+
} /* while */
498
+
499
+
return c;
500
+
}
501
+
453
502
/**
454
-
* unpack_trans_table - unpack a profile transition table
503
+
* unpack_strs_table - unpack a profile transition table
455
504
* @e: serialized data extent information (NOT NULL)
505
+
* @name: name of table (MAY BE NULL)
506
+
* @multi: allow multiple strings on a single entry
456
507
* @strs: str table to unpack to (NOT NULL)
457
508
*
458
509
* Returns: true if table successfully unpacked or not present
459
510
*/
460
-
static bool unpack_trans_table(struct aa_ext *e, struct aa_str_table *strs)
511
+
static bool unpack_strs_table(struct aa_ext *e, const char *name, bool multi,
512
+
struct aa_str_table *strs)
461
513
{
462
514
void *saved_pos = e->pos;
463
-
char **table = NULL;
515
+
struct aa_str_table_ent *table = NULL;
464
516
465
517
/* exec table is optional */
466
-
if (aa_unpack_nameX(e, AA_STRUCT, "xtable")) {
518
+
if (aa_unpack_nameX(e, AA_STRUCT, name)) {
467
519
u16 size;
468
520
int i;
469
521
···
527
475
* for size check here
528
476
*/
529
477
goto fail;
530
-
table = kcalloc(size, sizeof(char *), GFP_KERNEL);
478
+
table = kcalloc(size, sizeof(struct aa_str_table_ent),
479
+
GFP_KERNEL);
531
480
if (!table)
532
481
goto fail;
533
482
···
536
483
strs->size = size;
537
484
for (i = 0; i < size; i++) {
538
485
char *str;
539
-
int c, j, pos, size2 = aa_unpack_strdup(e, &str, NULL);
486
+
int c, size2 = aa_unpack_strdup(e, &str, NULL);
540
487
/* aa_unpack_strdup verifies that the last character is
541
488
* null termination byte.
542
489
*/
543
-
if (!size2)
490
+
c = process_strs_entry(str, size2, multi);
491
+
if (c <= 0) {
492
+
AA_DEBUG(DEBUG_UNPACK, "process_strs %d", c);
544
493
goto fail;
545
-
table[i] = str;
546
-
/* verify that name doesn't start with space */
547
-
if (isspace(*str))
548
-
goto fail;
549
-
550
-
/* count internal # of internal \0 */
551
-
for (c = j = 0; j < size2 - 1; j++) {
552
-
if (!str[j]) {
553
-
pos = j;
554
-
c++;
555
-
}
556
494
}
557
-
if (*str == ':') {
558
-
/* first character after : must be valid */
559
-
if (!str[1])
560
-
goto fail;
561
-
/* beginning with : requires an embedded \0,
562
-
* verify that exactly 1 internal \0 exists
563
-
* trailing \0 already verified by aa_unpack_strdup
564
-
*
565
-
* convert \0 back to : for label_parse
566
-
*/
567
-
if (c == 1)
568
-
str[pos] = ':';
569
-
else if (c > 1)
570
-
goto fail;
571
-
} else if (c)
495
+
if (!multi && c > 1) {
496
+
AA_DEBUG(DEBUG_UNPACK, "!multi && c > 1");
572
497
/* fail - all other cases with embedded \0 */
573
498
goto fail;
499
+
}
500
+
table[i].strs = str;
501
+
table[i].count = c;
502
+
table[i].size = size2;
574
503
}
575
504
if (!aa_unpack_nameX(e, AA_ARRAYEND, NULL))
576
505
goto fail;
···
562
527
return true;
563
528
564
529
fail:
565
-
aa_free_str_table(strs);
530
+
aa_destroy_str_table(strs);
566
531
e->pos = saved_pos;
567
532
return false;
568
533
}
···
830
795
* transition table may be present even when the dfa is
831
796
* not. For compatibility reasons unpack and discard.
832
797
*/
833
-
if (!unpack_trans_table(e, &pdb->trans) && required_trans) {
798
+
if (!unpack_strs_table(e, "xtable", false, &pdb->trans) &&
799
+
required_trans) {
834
800
*info = "failed to unpack profile transition table";
835
801
goto fail;
836
802
}
837
803
838
804
if (!pdb->dfa && pdb->trans.table)
839
-
aa_free_str_table(&pdb->trans);
805
+
aa_destroy_str_table(&pdb->trans);
840
806
841
807
/* TODO:
842
808
* - move compat mapping here, requires dfa merging first
···
1304
1268
}
1305
1269
/* deal with incorrectly constructed string tables */
1306
1270
if (xmax == -1) {
1307
-
aa_free_str_table(&pdb->trans);
1271
+
aa_destroy_str_table(&pdb->trans);
1308
1272
} else if (pdb->trans.size > xmax + 1) {
1309
1273
if (!aa_resize_str_table(&pdb->trans, xmax + 1, GFP_KERNEL))
1310
1274
return false;