[PATCH AUTOSEL 5.6 082/606] ima: Set file->f_mode instead of file->f_flags in ima_calc_file_hash()

[PATCH AUTOSEL 5.6 082/606] ima: Set file->f_mode instead of file->f_flags in ima_calc_file_hash()

[Sasha Levin]

From: Roberto Sassu <roberto.sassu@huawei.com>

[ Upstream commit 0014cc04e8ec077dc482f00c87dfd949cfe2b98f ]

Commit a408e4a86b36 ("ima: open a new file instance if no read
permissions") tries to create a new file descriptor to calculate a file
digest if the file has not been opened with O_RDONLY flag. However, if a
new file descriptor cannot be obtained, it sets the FMODE_READ flag to
file->f_flags instead of file->f_mode.

This patch fixes this issue by replacing f_flags with f_mode as it was
before that commit.

Cc: stable@vger.kernel.org # 4.20.x
Fixes: a408e4a86b36 ("ima: open a new file instance if no read permissions")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/integrity/ima/ima_crypto.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/security/integrity/ima/ima_crypto.c b/security/integrity/ima/ima_crypto.c
index 7967a6904851..e8fa23cd4a6c 100644
--- a/security/integrity/ima/ima_crypto.c
+++ b/security/integrity/ima/ima_crypto.c
@@ -413,7 +413,7 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
 	loff_t i_size;
 	int rc;
 	struct file *f = file;
-	bool new_file_instance = false, modified_flags = false;
+	bool new_file_instance = false, modified_mode = false;
 
 	/*
 	 * For consistency, fail file's opened with the O_DIRECT flag on
@@ -433,13 +433,13 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
 		f = dentry_open(&file->f_path, flags, file->f_cred);
 		if (IS_ERR(f)) {
 			/*
-			 * Cannot open the file again, lets modify f_flags
+			 * Cannot open the file again, lets modify f_mode
 			 * of original and continue
 			 */
 			pr_info_ratelimited("Unable to reopen file for reading.\n");
 			f = file;
-			f->f_flags |= FMODE_READ;
-			modified_flags = true;
+			f->f_mode |= FMODE_READ;
+			modified_mode = true;
 		} else {
 			new_file_instance = true;
 		}
@@ -457,8 +457,8 @@ int ima_calc_file_hash(struct file *file, struct ima_digest_data *hash)
 out:
 	if (new_file_instance)
 		fput(f);
-	else if (modified_flags)
-		f->f_flags &= ~FMODE_READ;
+	else if (modified_mode)
+		f->f_mode &= ~FMODE_READ;
 	return rc;
 }
 
-- 
2.25.1

[PATCH AUTOSEL 5.6 083/606] evm: Check also if *tfm is an error pointer in init_desc()

[Sasha Levin]

From: Roberto Sassu <roberto.sassu@huawei.com>

[ Upstream commit 53de3b080d5eae31d0de219617155dcc34e7d698 ]

This patch avoids a kernel panic due to accessing an error pointer set by
crypto_alloc_shash(). It occurs especially when there are many files that
require an unsupported algorithm, as it would increase the likelihood of
the following race condition:

Task A: *tfm = crypto_alloc_shash() <= error pointer
Task B: if (*tfm == NULL) <= *tfm is not NULL, use it
Task B: rc = crypto_shash_init(desc) <= panic
Task A: *tfm = NULL

This patch uses the IS_ERR_OR_NULL macro to determine whether or not a new
crypto context must be created.

Cc: stable@vger.kernel.org
Fixes: d46eb3699502b ("evm: crypto hash replaced by shash")
Co-developed-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/integrity/evm/evm_crypto.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index d485f6fc908e..302adeb2d37b 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -93,7 +93,7 @@ static struct shash_desc *init_desc(char type, uint8_t hash_algo)
 		algo = hash_algo_name[hash_algo];
 	}
 
-	if (*tfm == NULL) {
+	if (IS_ERR_OR_NULL(*tfm)) {
 		mutex_lock(&mutex);
 		if (*tfm)
 			goto out;
-- 
2.25.1

[PATCH AUTOSEL 5.6 084/606] ima: Fix return value of ima_write_policy()

[Sasha Levin]

From: Roberto Sassu <roberto.sassu@huawei.com>

[ Upstream commit 2e3a34e9f409ebe83d1af7cd2f49fca7af97dfac ]

This patch fixes the return value of ima_write_policy() when a new policy
is directly passed to IMA and the current policy requires appraisal of the
file containing the policy. Currently, if appraisal is not in ENFORCE mode,
ima_write_policy() returns 0 and leads user space applications to an
endless loop. Fix this issue by denying the operation regardless of the
appraisal mode.

Cc: stable@vger.kernel.org # 4.10.x
Fixes: 19f8a84713edc ("ima: measure and appraise the IMA policy itself")
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/integrity/ima/ima_fs.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index 2000e8df0301..68571c40d61f 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c
@@ -340,8 +340,7 @@ static ssize_t ima_write_policy(struct file *file, const char __user *buf,
 		integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL,
 				    "policy_update", "signed policy required",
 				    1, 0);
-		if (ima_appraise & IMA_APPRAISE_ENFORCE)
-			result = -EACCES;
+		result = -EACCES;
 	} else {
 		result = ima_parse_add_rule(data);
 	}
-- 
2.25.1

[PATCH AUTOSEL 5.6 095/606] evm: Fix a small race in init_desc()

[Sasha Levin]

From: Dan Carpenter <dan.carpenter@oracle.com>

[ Upstream commit 8433856947217ebb5697a8ff9c4c9cad4639a2cf ]

The IS_ERR_OR_NULL() function has two conditions and if we got really
unlucky we could hit a race where "ptr" started as an error pointer and
then was set to NULL.  Both conditions would be false even though the
pointer at the end was NULL.

This patch fixes the problem by ensuring that "*tfm" can only be NULL
or valid.  I have introduced a "tmp_tfm" variable to make that work.  I
also reversed a condition and pulled the code in one tab.

Reported-by: Roberto Sassu <roberto.sassu@huawei.com>
Fixes: 53de3b080d5e ("evm: Check also if *tfm is an error pointer in init_desc()")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/integrity/evm/evm_crypto.c | 44 ++++++++++++++---------------
 1 file changed, 22 insertions(+), 22 deletions(-)

diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c
index 302adeb2d37b..cc826c2767a3 100644
--- a/security/integrity/evm/evm_crypto.c
+++ b/security/integrity/evm/evm_crypto.c
@@ -75,7 +75,7 @@ static struct shash_desc *init_desc(char type, uint8_t hash_algo)
 {
 	long rc;
 	const char *algo;
-	struct crypto_shash **tfm;
+	struct crypto_shash **tfm, *tmp_tfm;
 	struct shash_desc *desc;
 
 	if (type == EVM_XATTR_HMAC) {
@@ -93,31 +93,31 @@ static struct shash_desc *init_desc(char type, uint8_t hash_algo)
 		algo = hash_algo_name[hash_algo];
 	}
 
-	if (IS_ERR_OR_NULL(*tfm)) {
-		mutex_lock(&mutex);
-		if (*tfm)
-			goto out;
-		*tfm = crypto_alloc_shash(algo, 0, CRYPTO_NOLOAD);
-		if (IS_ERR(*tfm)) {
-			rc = PTR_ERR(*tfm);
-			pr_err("Can not allocate %s (reason: %ld)\n", algo, rc);
-			*tfm = NULL;
+	if (*tfm)
+		goto alloc;
+	mutex_lock(&mutex);
+	if (*tfm)
+		goto unlock;
+
+	tmp_tfm = crypto_alloc_shash(algo, 0, CRYPTO_NOLOAD);
+	if (IS_ERR(tmp_tfm)) {
+		pr_err("Can not allocate %s (reason: %ld)\n", algo,
+		       PTR_ERR(tmp_tfm));
+		mutex_unlock(&mutex);
+		return ERR_CAST(tmp_tfm);
+	}
+	if (type == EVM_XATTR_HMAC) {
+		rc = crypto_shash_setkey(tmp_tfm, evmkey, evmkey_len);
+		if (rc) {
+			crypto_free_shash(tmp_tfm);
 			mutex_unlock(&mutex);
 			return ERR_PTR(rc);
 		}
-		if (type == EVM_XATTR_HMAC) {
-			rc = crypto_shash_setkey(*tfm, evmkey, evmkey_len);
-			if (rc) {
-				crypto_free_shash(*tfm);
-				*tfm = NULL;
-				mutex_unlock(&mutex);
-				return ERR_PTR(rc);
-			}
-		}
-out:
-		mutex_unlock(&mutex);
 	}
-
+	*tfm = tmp_tfm;
+unlock:
+	mutex_unlock(&mutex);
+alloc:
 	desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(*tfm),
 			GFP_KERNEL);
 	if (!desc)
-- 
2.25.1

[PATCH AUTOSEL 5.6 153/606] apparmor: Fix use-after-free in aa_audit_rule_init

[Sasha Levin]

From: Navid Emamdoost <navid.emamdoost@gmail.com>

commit c54d481d71c6849e044690d3960aaebc730224cc upstream.

In the implementation of aa_audit_rule_init(), when aa_label_parse()
fails the allocated memory for rule is released using
aa_audit_rule_free(). But after this release, the return statement
tries to access the label field of the rule which results in
use-after-free. Before releasing the rule, copy errNo and return it
after release.

Fixes: 52e8c38001d8 ("apparmor: Fix memory leak of rule on error exit path")
Signed-off-by: Navid Emamdoost <navid.emamdoost@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 security/apparmor/audit.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/security/apparmor/audit.c b/security/apparmor/audit.c
index 5a98661a8b46..597732503815 100644
--- a/security/apparmor/audit.c
+++ b/security/apparmor/audit.c
@@ -197,8 +197,9 @@ int aa_audit_rule_init(u32 field, u32 op, char *rulestr, void **vrule)
 	rule->label = aa_label_parse(&root_ns->unconfined->label, rulestr,
 				     GFP_KERNEL, true, false);
 	if (IS_ERR(rule->label)) {
+		int err = PTR_ERR(rule->label);
 		aa_audit_rule_free(rule);
-		return PTR_ERR(rule->label);
+		return err;
 	}
 
 	*vrule = rule;
-- 
2.25.1

[PATCH AUTOSEL 5.6 154/606] apparmor: fix potential label refcnt leak in aa_change_profile

[Sasha Levin]

From: Xiyu Yang <xiyuyang19@fudan.edu.cn>

commit a0b845ffa0d91855532b50fc040aeb2d8338dca4 upstream.

aa_change_profile() invokes aa_get_current_label(), which returns
a reference of the current task's label.

According to the comment of aa_get_current_label(), the returned
reference must be put with aa_put_label().
However, when the original object pointed by "label" becomes
unreachable because aa_change_profile() returns or a new object
is assigned to "label", reference count increased by
aa_get_current_label() is not decreased, causing a refcnt leak.

Fix this by calling aa_put_label() before aa_change_profile() return
and dropping unnecessary aa_get_current_label().

Fixes: 9fcf78cca198 ("apparmor: update domain transitions that are subsets of confinement at nnp")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 security/apparmor/domain.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index 6ceb74e0f789..a84ef030fbd7 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -1328,6 +1328,7 @@ int aa_change_profile(const char *fqname, int flags)
 		ctx->nnp = aa_get_label(label);
 
 	if (!fqname || !*fqname) {
+		aa_put_label(label);
 		AA_DEBUG("no profile name");
 		return -EINVAL;
 	}
@@ -1346,8 +1347,6 @@ int aa_change_profile(const char *fqname, int flags)
 			op = OP_CHANGE_PROFILE;
 	}
 
-	label = aa_get_current_label();
-
 	if (*fqname == '&') {
 		stack = true;
 		/* don't have label_parse() do stacking */
-- 
2.25.1

[PATCH AUTOSEL 5.6 155/606] apparmor: Fix aa_label refcnt leak in policy_update

[Sasha Levin]

From: Xiyu Yang <xiyuyang19@fudan.edu.cn>

commit c6b39f070722ea9963ffe756bfe94e89218c5e63 upstream.

policy_update() invokes begin_current_label_crit_section(), which
returns a reference of the updated aa_label object to "label" with
increased refcount.

When policy_update() returns, "label" becomes invalid, so the refcount
should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
policy_update(). When aa_may_manage_policy() returns not NULL, the
refcnt increased by begin_current_label_crit_section() is not decreased,
causing a refcnt leak.

Fix this issue by jumping to "end_section" label when
aa_may_manage_policy() returns not NULL.

Fixes: 5ac8c355ae00 ("apparmor: allow introspecting the loaded policy pre internal transform")
Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 security/apparmor/apparmorfs.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 280741fc0f5f..f6a3ecfadf80 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -454,7 +454,7 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size,
 	 */
 	error = aa_may_manage_policy(label, ns, mask);
 	if (error)
-		return error;
+		goto end_section;
 
 	data = aa_simple_write_to_buffer(buf, size, size, pos);
 	error = PTR_ERR(data);
@@ -462,6 +462,7 @@ static ssize_t policy_update(u32 mask, const char __user *buf, size_t size,
 		error = aa_replace_profiles(ns, label, mask, data);
 		aa_put_loaddata(data);
 	}
+end_section:
 	end_current_label_crit_section(label);
 
 	return error;
-- 
2.25.1

[PATCH AUTOSEL 5.6 321/606] exec: Always set cap_ambient in cap_bprm_set_creds

[Sasha Levin]

From: "Eric W. Biederman" <ebiederm@xmission.com>

[ Upstream commit a4ae32c71fe90794127b32d26d7ad795813b502e ]

An invariant of cap_bprm_set_creds is that every field in the new cred
structure that cap_bprm_set_creds might set, needs to be set every
time to ensure the fields does not get a stale value.

The field cap_ambient is not set every time cap_bprm_set_creds is
called, which means that if there is a suid or sgid script with an
interpreter that has neither the suid nor the sgid bits set the
interpreter should be able to accept ambient credentials.
Unfortuantely because cap_ambient is not reset to it's original value
the interpreter can not accept ambient credentials.

Given that the ambient capability set is expected to be controlled by
the caller, I don't think this is particularly serious.  But it is
definitely worth fixing so the code works correctly.

I have tested to verify my reading of the code is correct and the
interpreter of a sgid can receive ambient capabilities with this
change and cannot receive ambient capabilities without this change.

Cc: stable@vger.kernel.org
Cc: Andy Lutomirski <luto@kernel.org>
Fixes: 58319057b784 ("capabilities: ambient capabilities")
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 security/commoncap.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/security/commoncap.c b/security/commoncap.c
index f4ee0ae106b2..0ca31c8bc0b1 100644
--- a/security/commoncap.c
+++ b/security/commoncap.c
@@ -812,6 +812,7 @@ int cap_bprm_set_creds(struct linux_binprm *bprm)
 	int ret;
 	kuid_t root_uid;
 
+	new->cap_ambient = old->cap_ambient;
 	if (WARN_ON(!cap_ambient_invariant_ok(old)))
 		return -EPERM;
 
-- 
2.25.1