summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
Diffstat
-rw-r--r--drivers/base/firmware_loader/main.c59
-rw-r--r--drivers/block/nbd.c54
-rw-r--r--drivers/target/target_core_configfs.c14
-rw-r--r--include/linux/cleanup.h15
-rw-r--r--include/linux/cred.h15
-rw-r--r--include/linux/init_task.h1
-rw-r--r--init/init_task.c27
-rw-r--r--kernel/cred.c27
-rw-r--r--net/unix/af_unix.c17
-rw-r--r--security/keys/process_keys.c2
10 files changed, 103 insertions, 128 deletions
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index 6942c62fa59d..bee3050a20d9 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -829,8 +829,6 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
size_t offset, u32 opt_flags)
{
struct firmware *fw = NULL;
- struct cred *kern_cred = NULL;
- const struct cred *old_cred;
bool nondirect = false;
int ret;
@@ -871,45 +869,38 @@ _request_firmware(const struct firmware **firmware_p, const char *name,
* called by a driver when serving an unrelated request from userland, we use
* the kernel credentials to read the file.
*/
- kern_cred = prepare_kernel_cred(&init_task);
- if (!kern_cred) {
- ret = -ENOMEM;
- goto out;
- }
- old_cred = override_creds(kern_cred);
+ scoped_with_kernel_creds() {
+ ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
- ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
-
- /* Only full reads can support decompression, platform, and sysfs. */
- if (!(opt_flags & FW_OPT_PARTIAL))
- nondirect = true;
+ /* Only full reads can support decompression, platform, and sysfs. */
+ if (!(opt_flags & FW_OPT_PARTIAL))
+ nondirect = true;
#ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
- if (ret == -ENOENT && nondirect)
- ret = fw_get_filesystem_firmware(device, fw->priv, ".zst",
- fw_decompress_zstd);
+ if (ret == -ENOENT && nondirect)
+ ret = fw_get_filesystem_firmware(device, fw->priv, ".zst",
+ fw_decompress_zstd);
#endif
#ifdef CONFIG_FW_LOADER_COMPRESS_XZ
- if (ret == -ENOENT && nondirect)
- ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
- fw_decompress_xz);
+ if (ret == -ENOENT && nondirect)
+ ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
+ fw_decompress_xz);
#endif
- if (ret == -ENOENT && nondirect)
- ret = firmware_fallback_platform(fw->priv);
+ if (ret == -ENOENT && nondirect)
+ ret = firmware_fallback_platform(fw->priv);
- if (ret) {
- if (!(opt_flags & FW_OPT_NO_WARN))
- dev_warn(device,
- "Direct firmware load for %s failed with error %d\n",
- name, ret);
- if (nondirect)
- ret = firmware_fallback_sysfs(fw, name, device,
- opt_flags, ret);
- } else
- ret = assign_fw(fw, device);
-
- revert_creds(old_cred);
- put_cred(kern_cred);
+ if (ret) {
+ if (!(opt_flags & FW_OPT_NO_WARN))
+ dev_warn(device,
+ "Direct firmware load for %s failed with error %d\n",
+ name, ret);
+ if (nondirect)
+ ret = firmware_fallback_sysfs(fw, name, device,
+ opt_flags, ret);
+ } else {
+ ret = assign_fw(fw, device);
+ }
+ }
out:
if (ret < 0) {
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index a853c65ac65d..3263040fcf2d 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -52,7 +52,6 @@
static DEFINE_IDR(nbd_index_idr);
static DEFINE_MUTEX(nbd_index_mutex);
static struct workqueue_struct *nbd_del_wq;
-static struct cred *nbd_cred;
static int nbd_total_devices = 0;
struct nbd_sock {
@@ -555,7 +554,6 @@ static int __sock_xmit(struct nbd_device *nbd, struct socket *sock, int send,
int result;
struct msghdr msg = {} ;
unsigned int noreclaim_flag;
- const struct cred *old_cred;
if (unlikely(!sock)) {
dev_err_ratelimited(disk_to_dev(nbd->disk),
@@ -564,33 +562,32 @@ static int __sock_xmit(struct nbd_device *nbd, struct socket *sock, int send,
return -EINVAL;
}
- old_cred = override_creds(nbd_cred);
-
msg.msg_iter = *iter;
noreclaim_flag = memalloc_noreclaim_save();
- do {
- sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC;
- sock->sk->sk_use_task_frag = false;
- msg.msg_flags = msg_flags | MSG_NOSIGNAL;
-
- if (send)
- result = sock_sendmsg(sock, &msg);
- else
- result = sock_recvmsg(sock, &msg, msg.msg_flags);
-
- if (result <= 0) {
- if (result == 0)
- result = -EPIPE; /* short read */
- break;
- }
- if (sent)
- *sent += result;
- } while (msg_data_left(&msg));
- memalloc_noreclaim_restore(noreclaim_flag);
+ scoped_with_kernel_creds() {
+ do {
+ sock->sk->sk_allocation = GFP_NOIO | __GFP_MEMALLOC;
+ sock->sk->sk_use_task_frag = false;
+ msg.msg_flags = msg_flags | MSG_NOSIGNAL;
- revert_creds(old_cred);
+ if (send)
+ result = sock_sendmsg(sock, &msg);
+ else
+ result = sock_recvmsg(sock, &msg, msg.msg_flags);
+
+ if (result <= 0) {
+ if (result == 0)
+ result = -EPIPE; /* short read */
+ break;
+ }
+ if (sent)
+ *sent += result;
+ } while (msg_data_left(&msg));
+ }
+
+ memalloc_noreclaim_restore(noreclaim_flag);
return result;
}
@@ -2683,15 +2680,7 @@ static int __init nbd_init(void)
return -ENOMEM;
}
- nbd_cred = prepare_kernel_cred(&init_task);
- if (!nbd_cred) {
- destroy_workqueue(nbd_del_wq);
- unregister_blkdev(NBD_MAJOR, "nbd");
- return -ENOMEM;
- }
-
if (genl_register_family(&nbd_genl_family)) {
- put_cred(nbd_cred);
destroy_workqueue(nbd_del_wq);
unregister_blkdev(NBD_MAJOR, "nbd");
return -EINVAL;
@@ -2746,7 +2735,6 @@ static void __exit nbd_cleanup(void)
/* Also wait for nbd_dev_remove_work() completes */
destroy_workqueue(nbd_del_wq);
- put_cred(nbd_cred);
idr_destroy(&nbd_index_idr);
unregister_blkdev(NBD_MAJOR, "nbd");
}
diff --git a/drivers/target/target_core_configfs.c b/drivers/target/target_core_configfs.c
index b19acd662726..9e51c535ba8c 100644
--- a/drivers/target/target_core_configfs.c
+++ b/drivers/target/target_core_configfs.c
@@ -3670,8 +3670,6 @@ static int __init target_core_init_configfs(void)
{
struct configfs_subsystem *subsys = &target_core_fabrics;
struct t10_alua_lu_gp *lu_gp;
- struct cred *kern_cred;
- const struct cred *old_cred;
int ret;
pr_debug("TARGET_CORE[0]: Loading Generic Kernel Storage"
@@ -3748,16 +3746,8 @@ static int __init target_core_init_configfs(void)
if (ret < 0)
goto out;
- /* We use the kernel credentials to access the target directory */
- kern_cred = prepare_kernel_cred(&init_task);
- if (!kern_cred) {
- ret = -ENOMEM;
- goto out;
- }
- old_cred = override_creds(kern_cred);
- target_init_dbroot();
- revert_creds(old_cred);
- put_cred(kern_cred);
+ scoped_with_kernel_creds()
+ target_init_dbroot();
return 0;
diff --git a/include/linux/cleanup.h b/include/linux/cleanup.h
index 2573585b7f06..19c7e475d3a4 100644
--- a/include/linux/cleanup.h
+++ b/include/linux/cleanup.h
@@ -290,15 +290,16 @@ static inline class_##_name##_t class_##_name##ext##_constructor(_init_args) \
class_##_name##_t var __cleanup(class_##_name##_destructor) = \
class_##_name##_constructor
-#define scoped_class(_name, var, args) \
- for (CLASS(_name, var)(args); \
- __guard_ptr(_name)(&var) || !__is_cond_ptr(_name); \
- ({ goto _label; })) \
- if (0) { \
-_label: \
- break; \
+#define __scoped_class(_name, var, _label, args...) \
+ for (CLASS(_name, var)(args); ; ({ goto _label; })) \
+ if (0) { \
+_label: \
+ break; \
} else
+#define scoped_class(_name, var, args...) \
+ __scoped_class(_name, var, __UNIQUE_ID(label), args)
+
/*
* DEFINE_GUARD(name, type, lock, unlock):
* trivial wrapper around DEFINE_CLASS() above specifically
diff --git a/include/linux/cred.h b/include/linux/cred.h
index 89ae50ad2ace..be2cd07b174c 100644
--- a/include/linux/cred.h
+++ b/include/linux/cred.h
@@ -20,6 +20,8 @@
struct cred;
struct inode;
+extern struct task_struct init_task;
+
/*
* COW Supplementary groups list
*/
@@ -156,6 +158,11 @@ extern struct cred *prepare_exec_creds(void);
extern int commit_creds(struct cred *);
extern void abort_creds(struct cred *);
extern struct cred *prepare_kernel_cred(struct task_struct *);
+static inline const struct cred *kernel_cred(void)
+{
+ /* shut up sparse */
+ return rcu_dereference_raw(init_task.cred);
+}
extern int set_security_override(struct cred *, u32);
extern int set_security_override_from_ctx(struct cred *, const char *);
extern int set_create_files_as(struct cred *, struct inode *);
@@ -180,6 +187,14 @@ static inline const struct cred *revert_creds(const struct cred *revert_cred)
return rcu_replace_pointer(current->cred, revert_cred, 1);
}
+DEFINE_CLASS(override_creds,
+ const struct cred *,
+ revert_creds(_T),
+ override_creds(override_cred), const struct cred *override_cred)
+
+#define scoped_with_kernel_creds() \
+ scoped_class(override_creds, __UNIQUE_ID(cred), kernel_cred())
+
/**
* get_cred_many - Get references on a set of credentials
* @cred: The credentials to reference
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index bccb3f1f6262..a6cb241ea00c 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -25,7 +25,6 @@
extern struct files_struct init_files;
extern struct fs_struct init_fs;
extern struct nsproxy init_nsproxy;
-extern struct cred init_cred;
#ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
#define INIT_PREV_CPUTIME(x) .prev_cputime = { \
diff --git a/init/init_task.c b/init/init_task.c
index a55e2189206f..d970a847b657 100644
--- a/init/init_task.c
+++ b/init/init_task.c
@@ -62,6 +62,33 @@ unsigned long init_shadow_call_stack[SCS_SIZE / sizeof(long)] = {
};
#endif
+/* init to 2 - one for init_task, one to ensure it is never freed */
+static struct group_info init_groups = { .usage = REFCOUNT_INIT(2) };
+
+/*
+ * The initial credentials for the initial task
+ */
+static struct cred init_cred = {
+ .usage = ATOMIC_INIT(4),
+ .uid = GLOBAL_ROOT_UID,
+ .gid = GLOBAL_ROOT_GID,
+ .suid = GLOBAL_ROOT_UID,
+ .sgid = GLOBAL_ROOT_GID,
+ .euid = GLOBAL_ROOT_UID,
+ .egid = GLOBAL_ROOT_GID,
+ .fsuid = GLOBAL_ROOT_UID,
+ .fsgid = GLOBAL_ROOT_GID,
+ .securebits = SECUREBITS_DEFAULT,
+ .cap_inheritable = CAP_EMPTY_SET,
+ .cap_permitted = CAP_FULL_SET,
+ .cap_effective = CAP_FULL_SET,
+ .cap_bset = CAP_FULL_SET,
+ .user = INIT_USER,
+ .user_ns = &init_user_ns,
+ .group_info = &init_groups,
+ .ucounts = &init_ucounts,
+};
+
/*
* Set up the first task table, touch at your own risk!. Base=0,
* limit=0x1fffff (=2MB)
diff --git a/kernel/cred.c b/kernel/cred.c
index dbf6b687dc5c..ac87ed9d43b1 100644
--- a/kernel/cred.c
+++ b/kernel/cred.c
@@ -35,33 +35,6 @@ do { \
static struct kmem_cache *cred_jar;
-/* init to 2 - one for init_task, one to ensure it is never freed */
-static struct group_info init_groups = { .usage = REFCOUNT_INIT(2) };
-
-/*
- * The initial credentials for the initial task
- */
-struct cred init_cred = {
- .usage = ATOMIC_INIT(4),
- .uid = GLOBAL_ROOT_UID,
- .gid = GLOBAL_ROOT_GID,
- .suid = GLOBAL_ROOT_UID,
- .sgid = GLOBAL_ROOT_GID,
- .euid = GLOBAL_ROOT_UID,
- .egid = GLOBAL_ROOT_GID,
- .fsuid = GLOBAL_ROOT_UID,
- .fsgid = GLOBAL_ROOT_GID,
- .securebits = SECUREBITS_DEFAULT,
- .cap_inheritable = CAP_EMPTY_SET,
- .cap_permitted = CAP_FULL_SET,
- .cap_effective = CAP_FULL_SET,
- .cap_bset = CAP_FULL_SET,
- .user = INIT_USER,
- .user_ns = &init_user_ns,
- .group_info = &init_groups,
- .ucounts = &init_ucounts,
-};
-
/*
* The RCU callback to actually dispose of a set of credentials
*/
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 768098dec231..68c94f49f7b5 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1210,25 +1210,16 @@ static struct sock *unix_find_bsd(struct sockaddr_un *sunaddr, int addr_len,
unix_mkname_bsd(sunaddr, addr_len);
if (flags & SOCK_COREDUMP) {
- const struct cred *cred;
- struct cred *kcred;
struct path root;
- kcred = prepare_kernel_cred(&init_task);
- if (!kcred) {
- err = -ENOMEM;
- goto fail;
- }
-
task_lock(&init_task);
get_fs_root(init_task.fs, &root);
task_unlock(&init_task);
- cred = override_creds(kcred);
- err = vfs_path_lookup(root.dentry, root.mnt, sunaddr->sun_path,
- LOOKUP_BENEATH | LOOKUP_NO_SYMLINKS |
- LOOKUP_NO_MAGICLINKS, &path);
- put_cred(revert_creds(cred));
+ scoped_with_kernel_creds()
+ err = vfs_path_lookup(root.dentry, root.mnt, sunaddr->sun_path,
+ LOOKUP_BENEATH | LOOKUP_NO_SYMLINKS |
+ LOOKUP_NO_MAGICLINKS, &path);
path_put(&root);
if (err)
goto fail;
diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
index b5d5333ab330..a63c46bb2d14 100644
--- a/security/keys/process_keys.c
+++ b/security/keys/process_keys.c
@@ -51,7 +51,7 @@ static struct key *get_user_register(struct user_namespace *user_ns)
if (!reg_keyring) {
reg_keyring = keyring_alloc(".user_reg",
user_ns->owner, INVALID_GID,
- &init_cred,
+ kernel_cred(),
KEY_POS_WRITE | KEY_POS_SEARCH |
KEY_USR_VIEW | KEY_USR_READ,
0,
generated by cgit (git 2.34.1) at 2025-12-09 13:01:26 +0000