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authorTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2021-02-01 11:52:11 +0900
committerTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>2021-02-01 11:52:11 +0900
commit5797e861e402fff2bedce4ec8b7c89f4248b6073 (patch)
tree8703689665da1be3512f2a3efa3024f6404dea9c /security
parent1048ba83fb1c00cd24172e23e8263972f6b5d9ac (diff)
tomoyo: ignore data race while checking quota
syzbot is reporting that tomoyo's quota check is racy [1]. But this check is tolerant of some degree of inaccuracy. Thus, teach KCSAN to ignore this data race. [1] https://syzkaller.appspot.com/bug?id=999533deec7ba6337f8aa25d8bd1a4d5f7e50476 Reported-by: syzbot <syzbot+0789a72b46fd91431bd8@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Diffstat (limited to 'security')
-rw-r--r--security/tomoyo/file.c16
-rw-r--r--security/tomoyo/network.c8
-rw-r--r--security/tomoyo/util.c24
3 files changed, 24 insertions, 24 deletions
diff --git a/security/tomoyo/file.c b/security/tomoyo/file.c
index 051f7297877c..1e6077568fde 100644
--- a/security/tomoyo/file.c
+++ b/security/tomoyo/file.c
@@ -362,14 +362,14 @@ static bool tomoyo_merge_path_acl(struct tomoyo_acl_info *a,
{
u16 * const a_perm = &container_of(a, struct tomoyo_path_acl, head)
->perm;
- u16 perm = *a_perm;
+ u16 perm = READ_ONCE(*a_perm);
const u16 b_perm = container_of(b, struct tomoyo_path_acl, head)->perm;
if (is_delete)
perm &= ~b_perm;
else
perm |= b_perm;
- *a_perm = perm;
+ WRITE_ONCE(*a_perm, perm);
return !perm;
}
@@ -437,7 +437,7 @@ static bool tomoyo_merge_mkdev_acl(struct tomoyo_acl_info *a,
{
u8 *const a_perm = &container_of(a, struct tomoyo_mkdev_acl,
head)->perm;
- u8 perm = *a_perm;
+ u8 perm = READ_ONCE(*a_perm);
const u8 b_perm = container_of(b, struct tomoyo_mkdev_acl, head)
->perm;
@@ -445,7 +445,7 @@ static bool tomoyo_merge_mkdev_acl(struct tomoyo_acl_info *a,
perm &= ~b_perm;
else
perm |= b_perm;
- *a_perm = perm;
+ WRITE_ONCE(*a_perm, perm);
return !perm;
}
@@ -517,14 +517,14 @@ static bool tomoyo_merge_path2_acl(struct tomoyo_acl_info *a,
{
u8 * const a_perm = &container_of(a, struct tomoyo_path2_acl, head)
->perm;
- u8 perm = *a_perm;
+ u8 perm = READ_ONCE(*a_perm);
const u8 b_perm = container_of(b, struct tomoyo_path2_acl, head)->perm;
if (is_delete)
perm &= ~b_perm;
else
perm |= b_perm;
- *a_perm = perm;
+ WRITE_ONCE(*a_perm, perm);
return !perm;
}
@@ -655,7 +655,7 @@ static bool tomoyo_merge_path_number_acl(struct tomoyo_acl_info *a,
{
u8 * const a_perm = &container_of(a, struct tomoyo_path_number_acl,
head)->perm;
- u8 perm = *a_perm;
+ u8 perm = READ_ONCE(*a_perm);
const u8 b_perm = container_of(b, struct tomoyo_path_number_acl, head)
->perm;
@@ -663,7 +663,7 @@ static bool tomoyo_merge_path_number_acl(struct tomoyo_acl_info *a,
perm &= ~b_perm;
else
perm |= b_perm;
- *a_perm = perm;
+ WRITE_ONCE(*a_perm, perm);
return !perm;
}
diff --git a/security/tomoyo/network.c b/security/tomoyo/network.c
index f9ff121d7e1e..a89ed55d85d4 100644
--- a/security/tomoyo/network.c
+++ b/security/tomoyo/network.c
@@ -233,14 +233,14 @@ static bool tomoyo_merge_inet_acl(struct tomoyo_acl_info *a,
{
u8 * const a_perm =
&container_of(a, struct tomoyo_inet_acl, head)->perm;
- u8 perm = *a_perm;
+ u8 perm = READ_ONCE(*a_perm);
const u8 b_perm = container_of(b, struct tomoyo_inet_acl, head)->perm;
if (is_delete)
perm &= ~b_perm;
else
perm |= b_perm;
- *a_perm = perm;
+ WRITE_ONCE(*a_perm, perm);
return !perm;
}
@@ -259,14 +259,14 @@ static bool tomoyo_merge_unix_acl(struct tomoyo_acl_info *a,
{
u8 * const a_perm =
&container_of(a, struct tomoyo_unix_acl, head)->perm;
- u8 perm = *a_perm;
+ u8 perm = READ_ONCE(*a_perm);
const u8 b_perm = container_of(b, struct tomoyo_unix_acl, head)->perm;
if (is_delete)
perm &= ~b_perm;
else
perm |= b_perm;
- *a_perm = perm;
+ WRITE_ONCE(*a_perm, perm);
return !perm;
}
diff --git a/security/tomoyo/util.c b/security/tomoyo/util.c
index 176b803ebcfc..e89cac913583 100644
--- a/security/tomoyo/util.c
+++ b/security/tomoyo/util.c
@@ -1058,30 +1058,30 @@ bool tomoyo_domain_quota_is_ok(struct tomoyo_request_info *r)
if (ptr->is_deleted)
continue;
+ /*
+ * Reading perm bitmap might race with tomoyo_merge_*() because
+ * caller does not hold tomoyo_policy_lock mutex. But exceeding
+ * max_learning_entry parameter by a few entries does not harm.
+ */
switch (ptr->type) {
case TOMOYO_TYPE_PATH_ACL:
- perm = container_of(ptr, struct tomoyo_path_acl, head)
- ->perm;
+ data_race(perm = container_of(ptr, struct tomoyo_path_acl, head)->perm);
break;
case TOMOYO_TYPE_PATH2_ACL:
- perm = container_of(ptr, struct tomoyo_path2_acl, head)
- ->perm;
+ data_race(perm = container_of(ptr, struct tomoyo_path2_acl, head)->perm);
break;
case TOMOYO_TYPE_PATH_NUMBER_ACL:
- perm = container_of(ptr, struct tomoyo_path_number_acl,
- head)->perm;
+ data_race(perm = container_of(ptr, struct tomoyo_path_number_acl, head)
+ ->perm);
break;
case TOMOYO_TYPE_MKDEV_ACL:
- perm = container_of(ptr, struct tomoyo_mkdev_acl,
- head)->perm;
+ data_race(perm = container_of(ptr, struct tomoyo_mkdev_acl, head)->perm);
break;
case TOMOYO_TYPE_INET_ACL:
- perm = container_of(ptr, struct tomoyo_inet_acl,
- head)->perm;
+ data_race(perm = container_of(ptr, struct tomoyo_inet_acl, head)->perm);
break;
case TOMOYO_TYPE_UNIX_ACL:
- perm = container_of(ptr, struct tomoyo_unix_acl,
- head)->perm;
+ data_race(perm = container_of(ptr, struct tomoyo_unix_acl, head)->perm);
break;
case TOMOYO_TYPE_MANUAL_TASK_ACL:
perm = 0;