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-rw-r--r--security/apparmor/domain.c26
-rw-r--r--security/apparmor/file.c24
-rw-r--r--security/apparmor/include/path.h49
-rw-r--r--security/apparmor/lsm.c111
-rw-r--r--security/apparmor/mount.c65
5 files changed, 164 insertions, 111 deletions
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index ca2dccf5b445..cae0e619ff4f 100644
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -689,20 +689,9 @@ static struct aa_label *profile_transition(struct aa_profile *profile,
} else if (COMPLAIN_MODE(profile)) {
/* no exec permission - learning mode */
struct aa_profile *new_profile = NULL;
- char *n = kstrdup(name, GFP_ATOMIC);
-
- if (n) {
- /* name is ptr into buffer */
- long pos = name - buffer;
- /* break per cpu buffer hold */
- put_buffers(buffer);
- new_profile = aa_new_null_profile(profile, false, n,
- GFP_KERNEL);
- get_buffers(buffer);
- name = buffer + pos;
- strcpy((char *)name, n);
- kfree(n);
- }
+
+ new_profile = aa_new_null_profile(profile, false, name,
+ GFP_KERNEL);
if (!new_profile) {
error = -ENOMEM;
info = "could not create null profile";
@@ -907,7 +896,12 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
ctx->nnp = aa_get_label(label);
/* buffer freed below, name is pointer into buffer */
- get_buffers(buffer);
+ buffer = aa_get_buffer();
+ if (!buffer) {
+ error = -ENOMEM;
+ goto done;
+ }
+
/* Test for onexec first as onexec override other x transitions. */
if (ctx->onexec)
new = handle_onexec(label, ctx->onexec, ctx->token,
@@ -979,7 +973,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
done:
aa_put_label(label);
- put_buffers(buffer);
+ aa_put_buffer(buffer);
return error;
diff --git a/security/apparmor/file.c b/security/apparmor/file.c
index d0afed9ebd0e..7b424e73a8c7 100644
--- a/security/apparmor/file.c
+++ b/security/apparmor/file.c
@@ -336,12 +336,14 @@ int aa_path_perm(const char *op, struct aa_label *label,
flags |= PATH_DELEGATE_DELETED | (S_ISDIR(cond->mode) ? PATH_IS_DIR :
0);
- get_buffers(buffer);
+ buffer = aa_get_buffer();
+ if (!buffer)
+ return -ENOMEM;
error = fn_for_each_confined(label, profile,
profile_path_perm(op, profile, path, buffer, request,
cond, flags, &perms));
- put_buffers(buffer);
+ aa_put_buffer(buffer);
return error;
}
@@ -479,12 +481,18 @@ int aa_path_link(struct aa_label *label, struct dentry *old_dentry,
int error;
/* buffer freed below, lname is pointer in buffer */
- get_buffers(buffer, buffer2);
+ buffer = aa_get_buffer();
+ buffer2 = aa_get_buffer();
+ error = -ENOMEM;
+ if (!buffer || !buffer2)
+ goto out;
+
error = fn_for_each_confined(label, profile,
profile_path_link(profile, &link, buffer, &target,
buffer2, &cond));
- put_buffers(buffer, buffer2);
-
+out:
+ aa_put_buffer(buffer);
+ aa_put_buffer(buffer2);
return error;
}
@@ -528,7 +536,9 @@ static int __file_path_perm(const char *op, struct aa_label *label,
return 0;
flags = PATH_DELEGATE_DELETED | (S_ISDIR(cond.mode) ? PATH_IS_DIR : 0);
- get_buffers(buffer);
+ buffer = aa_get_buffer();
+ if (!buffer)
+ return -ENOMEM;
/* check every profile in task label not in current cache */
error = fn_for_each_not_in_set(flabel, label, profile,
@@ -557,7 +567,7 @@ static int __file_path_perm(const char *op, struct aa_label *label,
if (!error)
update_file_ctx(file_ctx(file), label, request);
- put_buffers(buffer);
+ aa_put_buffer(buffer);
return error;
}
diff --git a/security/apparmor/include/path.h b/security/apparmor/include/path.h
index b6380c5f0097..b0b2ab85e42d 100644
--- a/security/apparmor/include/path.h
+++ b/security/apparmor/include/path.h
@@ -15,7 +15,6 @@
#ifndef __AA_PATH_H
#define __AA_PATH_H
-
enum path_flags {
PATH_IS_DIR = 0x1, /* path is a directory */
PATH_CONNECT_PATH = 0x4, /* connect disconnected paths to / */
@@ -30,51 +29,7 @@ int aa_path_name(const struct path *path, int flags, char *buffer,
const char **name, const char **info,
const char *disconnected);
-#define MAX_PATH_BUFFERS 2
-
-/* Per cpu buffers used during mediation */
-/* preallocated buffers to use during path lookups */
-struct aa_buffers {
- char *buf[MAX_PATH_BUFFERS];
-};
-
-#include <linux/percpu.h>
-#include <linux/preempt.h>
-
-DECLARE_PER_CPU(struct aa_buffers, aa_buffers);
-
-#define ASSIGN(FN, A, X, N) ((X) = FN(A, N))
-#define EVAL1(FN, A, X) ASSIGN(FN, A, X, 0) /*X = FN(0)*/
-#define EVAL2(FN, A, X, Y...) \
- do { ASSIGN(FN, A, X, 1); EVAL1(FN, A, Y); } while (0)
-#define EVAL(FN, A, X...) CONCATENATE(EVAL, COUNT_ARGS(X))(FN, A, X)
-
-#define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++)
-
-#ifdef CONFIG_DEBUG_PREEMPT
-#define AA_BUG_PREEMPT_ENABLED(X) AA_BUG(preempt_count() <= 0, X)
-#else
-#define AA_BUG_PREEMPT_ENABLED(X) /* nop */
-#endif
-
-#define __get_buffer(C, N) ({ \
- AA_BUG_PREEMPT_ENABLED("__get_buffer without preempt disabled"); \
- (C)->buf[(N)]; })
-
-#define __get_buffers(C, X...) EVAL(__get_buffer, C, X)
-
-#define __put_buffers(X, Y...) ((void)&(X))
-
-#define get_buffers(X...) \
-do { \
- struct aa_buffers *__cpu_var = get_cpu_ptr(&aa_buffers); \
- __get_buffers(__cpu_var, X); \
-} while (0)
-
-#define put_buffers(X, Y...) \
-do { \
- __put_buffers(X, Y); \
- put_cpu_ptr(&aa_buffers); \
-} while (0)
+char *aa_get_buffer(void);
+void aa_put_buffer(char *buf);
#endif /* __AA_PATH_H */
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 8f7ffc51ad86..3e0cfdebee45 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -48,8 +48,13 @@
/* Flag indicating whether initialization completed */
int apparmor_initialized;
-DEFINE_PER_CPU(struct aa_buffers, aa_buffers);
+union aa_buffer {
+ struct list_head list;
+ char buffer[1];
+};
+static LIST_HEAD(aa_global_buffers);
+static DEFINE_SPINLOCK(aa_buffers_lock);
/*
* LSM hook functions
@@ -1422,6 +1427,7 @@ static int param_set_aauint(const char *val, const struct kernel_param *kp)
return -EPERM;
error = param_set_uint(val, kp);
+ aa_g_path_max = max_t(uint32_t, aa_g_path_max, sizeof(union aa_buffer));
pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max);
return error;
@@ -1565,6 +1571,48 @@ static int param_set_mode(const char *val, const struct kernel_param *kp)
return 0;
}
+char *aa_get_buffer(void)
+{
+ union aa_buffer *aa_buf;
+ bool try_again = true;
+
+retry:
+ spin_lock(&aa_buffers_lock);
+ if (!list_empty(&aa_global_buffers)) {
+ aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
+ list);
+ list_del(&aa_buf->list);
+ spin_unlock(&aa_buffers_lock);
+ return &aa_buf->buffer[0];
+ }
+ spin_unlock(&aa_buffers_lock);
+
+ aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL | __GFP_RETRY_MAYFAIL |
+ __GFP_NOWARN);
+ if (!aa_buf) {
+ if (try_again) {
+ try_again = false;
+ goto retry;
+ }
+ pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n");
+ return NULL;
+ }
+ return &aa_buf->buffer[0];
+}
+
+void aa_put_buffer(char *buf)
+{
+ union aa_buffer *aa_buf;
+
+ if (!buf)
+ return;
+ aa_buf = container_of(buf, union aa_buffer, buffer[0]);
+
+ spin_lock(&aa_buffers_lock);
+ list_add(&aa_buf->list, &aa_global_buffers);
+ spin_unlock(&aa_buffers_lock);
+}
+
/*
* AppArmor init functions
*/
@@ -1585,38 +1633,48 @@ static int __init set_init_ctx(void)
static void destroy_buffers(void)
{
- u32 i, j;
+ union aa_buffer *aa_buf;
- for_each_possible_cpu(i) {
- for_each_cpu_buffer(j) {
- kfree(per_cpu(aa_buffers, i).buf[j]);
- per_cpu(aa_buffers, i).buf[j] = NULL;
- }
+ spin_lock(&aa_buffers_lock);
+ while (!list_empty(&aa_global_buffers)) {
+ aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer,
+ list);
+ list_del(&aa_buf->list);
+ spin_unlock(&aa_buffers_lock);
+ kfree(aa_buf);
+ spin_lock(&aa_buffers_lock);
}
+ spin_unlock(&aa_buffers_lock);
}
static int __init alloc_buffers(void)
{
- u32 i, j;
-
- for_each_possible_cpu(i) {
- for_each_cpu_buffer(j) {
- char *buffer;
-
- if (cpu_to_node(i) > num_online_nodes())
- /* fallback to kmalloc for offline nodes */
- buffer = kmalloc(aa_g_path_max, GFP_KERNEL);
- else
- buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL,
- cpu_to_node(i));
- if (!buffer) {
- destroy_buffers();
- return -ENOMEM;
- }
- per_cpu(aa_buffers, i).buf[j] = buffer;
+ union aa_buffer *aa_buf;
+ int i, num;
+
+ /*
+ * A function may require two buffers at once. Usually the buffers are
+ * used for a short period of time and are shared. On UP kernel buffers
+ * two should be enough, with more CPUs it is possible that more
+ * buffers will be used simultaneously. The preallocated pool may grow.
+ * This preallocation has also the side-effect that AppArmor will be
+ * disabled early at boot if aa_g_path_max is extremly high.
+ */
+ if (num_online_cpus() > 1)
+ num = 4;
+ else
+ num = 2;
+
+ for (i = 0; i < num; i++) {
+
+ aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL |
+ __GFP_RETRY_MAYFAIL | __GFP_NOWARN);
+ if (!aa_buf) {
+ destroy_buffers();
+ return -ENOMEM;
}
+ aa_put_buffer(&aa_buf->buffer[0]);
}
-
return 0;
}
@@ -1781,7 +1839,7 @@ static int __init apparmor_init(void)
error = alloc_buffers();
if (error) {
AA_ERROR("Unable to allocate work buffers\n");
- goto buffers_out;
+ goto alloc_out;
}
error = set_init_ctx();
@@ -1806,7 +1864,6 @@ static int __init apparmor_init(void)
buffers_out:
destroy_buffers();
-
alloc_out:
aa_destroy_aafs();
aa_teardown_dfa_engine();
diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c
index 8c3787399356..267a26fba14e 100644
--- a/security/apparmor/mount.c
+++ b/security/apparmor/mount.c
@@ -412,11 +412,13 @@ int aa_remount(struct aa_label *label, const struct path *path,
binary = path->dentry->d_sb->s_type->fs_flags & FS_BINARY_MOUNTDATA;
- get_buffers(buffer);
+ buffer = aa_get_buffer();
+ if (!buffer)
+ return -ENOMEM;
error = fn_for_each_confined(label, profile,
match_mnt(profile, path, buffer, NULL, NULL, NULL,
flags, data, binary));
- put_buffers(buffer);
+ aa_put_buffer(buffer);
return error;
}
@@ -441,11 +443,18 @@ int aa_bind_mount(struct aa_label *label, const struct path *path,
if (error)
return error;
- get_buffers(buffer, old_buffer);
+ buffer = aa_get_buffer();
+ old_buffer = aa_get_buffer();
+ error = -ENOMEM;
+ if (!buffer || old_buffer)
+ goto out;
+
error = fn_for_each_confined(label, profile,
match_mnt(profile, path, buffer, &old_path, old_buffer,
NULL, flags, NULL, false));
- put_buffers(buffer, old_buffer);
+out:
+ aa_put_buffer(buffer);
+ aa_put_buffer(old_buffer);
path_put(&old_path);
return error;
@@ -465,11 +474,13 @@ int aa_mount_change_type(struct aa_label *label, const struct path *path,
flags &= (MS_REC | MS_SILENT | MS_SHARED | MS_PRIVATE | MS_SLAVE |
MS_UNBINDABLE);
- get_buffers(buffer);
+ buffer = aa_get_buffer();
+ if (!buffer)
+ return -ENOMEM;
error = fn_for_each_confined(label, profile,
match_mnt(profile, path, buffer, NULL, NULL, NULL,
flags, NULL, false));
- put_buffers(buffer);
+ aa_put_buffer(buffer);
return error;
}
@@ -492,11 +503,17 @@ int aa_move_mount(struct aa_label *label, const struct path *path,
if (error)
return error;
- get_buffers(buffer, old_buffer);
+ buffer = aa_get_buffer();
+ old_buffer = aa_get_buffer();
+ error = -ENOMEM;
+ if (!buffer || !old_buffer)
+ goto out;
error = fn_for_each_confined(label, profile,
match_mnt(profile, path, buffer, &old_path, old_buffer,
NULL, MS_MOVE, NULL, false));
- put_buffers(buffer, old_buffer);
+out:
+ aa_put_buffer(buffer);
+ aa_put_buffer(old_buffer);
path_put(&old_path);
return error;
@@ -537,17 +554,29 @@ int aa_new_mount(struct aa_label *label, const char *dev_name,
}
}
- get_buffers(buffer, dev_buffer);
+ buffer = aa_get_buffer();
+ if (!buffer) {
+ error = -ENOMEM;
+ goto out;
+ }
if (dev_path) {
error = fn_for_each_confined(label, profile,
match_mnt(profile, path, buffer, dev_path, dev_buffer,
type, flags, data, binary));
} else {
+ dev_buffer = aa_get_buffer();
+ if (!dev_buffer) {
+ error = -ENOMEM;
+ goto out;
+ }
error = fn_for_each_confined(label, profile,
match_mnt_path_str(profile, path, buffer, dev_name,
type, flags, data, binary, NULL));
}
- put_buffers(buffer, dev_buffer);
+
+out:
+ aa_put_buffer(buffer);
+ aa_put_buffer(dev_buffer);
if (dev_path)
path_put(dev_path);
@@ -595,10 +624,13 @@ int aa_umount(struct aa_label *label, struct vfsmount *mnt, int flags)
AA_BUG(!label);
AA_BUG(!mnt);
- get_buffers(buffer);
+ buffer = aa_get_buffer();
+ if (!buffer)
+ return -ENOMEM;
+
error = fn_for_each_confined(label, profile,
profile_umount(profile, &path, buffer));
- put_buffers(buffer);
+ aa_put_buffer(buffer);
return error;
}
@@ -671,7 +703,11 @@ int aa_pivotroot(struct aa_label *label, const struct path *old_path,
AA_BUG(!old_path);
AA_BUG(!new_path);
- get_buffers(old_buffer, new_buffer);
+ old_buffer = aa_get_buffer();
+ new_buffer = aa_get_buffer();
+ error = -ENOMEM;
+ if (!old_buffer || !new_buffer)
+ goto out;
target = fn_label_build(label, profile, GFP_ATOMIC,
build_pivotroot(profile, new_path, new_buffer,
old_path, old_buffer));
@@ -690,7 +726,8 @@ int aa_pivotroot(struct aa_label *label, const struct path *old_path,
/* already audited error */
error = PTR_ERR(target);
out:
- put_buffers(old_buffer, new_buffer);
+ aa_put_buffer(old_buffer);
+ aa_put_buffer(new_buffer);
return error;
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-10 00:47:22 +0000