[PATCH v3 08/19] fs/kernel_read_file: Remove redundant size argument
From: Kees Cook <hidden>
Date: 2020-07-24 21:37:41
Also in:
linux-efi, linux-integrity, linux-kselftest, lkml, selinux
Subsystem:
driver core, kobjects, debugfs and sysfs, extended verification module (evm), filesystems (vfs and infrastructure), firmware loader (request_firmware), integrity measurement architecture (ima), kexec, security subsystem, the rest · Maintainers:
Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Mimi Zohar, Roberto Sassu, Alexander Viro, Christian Brauner, Luis Chamberlain, Russ Weight, Dmitry Kasatkin, Andrew Morton, Baoquan He, Mike Rapoport, Pasha Tatashin, Pratyush Yadav, Paul Moore, James Morris, "Serge E. Hallyn", Linus Torvalds
In preparation for refactoring kernel_read_file*(), remove the redundant "size" argument which is not needed: it can be included in the return code, with callers adjusted. (VFS reads already cannot be larger than INT_MAX.) Acked-by: Scott Branden <scott.branden@broadcom.com> Signed-off-by: Kees Cook <redacted> --- drivers/base/firmware_loader/main.c | 10 ++++++---- fs/kernel_read_file.c | 20 +++++++++----------- include/linux/kernel_read_file.h | 8 ++++---- kernel/kexec_file.c | 14 +++++++------- kernel/module.c | 7 +++---- security/integrity/digsig.c | 5 +++-- security/integrity/ima/ima_fs.c | 6 ++++-- 7 files changed, 36 insertions(+), 34 deletions(-)
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index d4a413ea48ce..f80c0d102be8 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c@@ -462,7 +462,7 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, size_t in_size, const void *in_buffer)) { - loff_t size; + size_t size; int i, len; int rc = -ENOENT; char *path;
@@ -494,10 +494,9 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, fw_priv->size = 0; /* load firmware files from the mount namespace of init */ - rc = kernel_read_file_from_path_initns(path, &buffer, - &size, msize, + rc = kernel_read_file_from_path_initns(path, &buffer, msize, READING_FIRMWARE); - if (rc) { + if (rc < 0) { if (rc != -ENOENT) dev_warn(device, "loading %s failed with error %d\n", path, rc);
@@ -506,6 +505,9 @@ fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, path); continue; } + size = rc; + rc = 0; + dev_dbg(device, "Loading firmware from %s\n", path); if (decompress) { dev_dbg(device, "f/w decompressing %s\n",
diff --git a/fs/kernel_read_file.c b/fs/kernel_read_file.c
index 54d972d4befc..dc28a8def597 100644
--- a/fs/kernel_read_file.c
+++ b/fs/kernel_read_file.c@@ -5,7 +5,7 @@ #include <linux/security.h> #include <linux/vmalloc.h> -int kernel_read_file(struct file *file, void **buf, loff_t *size, +int kernel_read_file(struct file *file, void **buf, loff_t max_size, enum kernel_read_file_id id) { loff_t i_size, pos;
@@ -29,7 +29,7 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, ret = -EINVAL; goto out; } - if (i_size > SIZE_MAX || (max_size > 0 && i_size > max_size)) { + if (i_size > INT_MAX || (max_size > 0 && i_size > max_size)) { ret = -EFBIG; goto out; }
@@ -59,8 +59,6 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, } ret = security_kernel_post_read_file(file, *buf, i_size, id); - if (!ret) - *size = pos; out_free: if (ret < 0) {
@@ -72,11 +70,11 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size, out: allow_write_access(file); - return ret; + return ret == 0 ? pos : ret; } EXPORT_SYMBOL_GPL(kernel_read_file); -int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, +int kernel_read_file_from_path(const char *path, void **buf, loff_t max_size, enum kernel_read_file_id id) { struct file *file;
@@ -89,14 +87,14 @@ int kernel_read_file_from_path(const char *path, void **buf, loff_t *size, if (IS_ERR(file)) return PTR_ERR(file); - ret = kernel_read_file(file, buf, size, max_size, id); + ret = kernel_read_file(file, buf, max_size, id); fput(file); return ret; } EXPORT_SYMBOL_GPL(kernel_read_file_from_path); int kernel_read_file_from_path_initns(const char *path, void **buf, - loff_t *size, loff_t max_size, + loff_t max_size, enum kernel_read_file_id id) { struct file *file;
@@ -115,13 +113,13 @@ int kernel_read_file_from_path_initns(const char *path, void **buf, if (IS_ERR(file)) return PTR_ERR(file); - ret = kernel_read_file(file, buf, size, max_size, id); + ret = kernel_read_file(file, buf, max_size, id); fput(file); return ret; } EXPORT_SYMBOL_GPL(kernel_read_file_from_path_initns); -int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, +int kernel_read_file_from_fd(int fd, void **buf, loff_t max_size, enum kernel_read_file_id id) { struct fd f = fdget(fd);
@@ -130,7 +128,7 @@ int kernel_read_file_from_fd(int fd, void **buf, loff_t *size, loff_t max_size, if (!f.file) goto out; - ret = kernel_read_file(f.file, buf, size, max_size, id); + ret = kernel_read_file(f.file, buf, max_size, id); out: fdput(f); return ret;
diff --git a/include/linux/kernel_read_file.h b/include/linux/kernel_read_file.h
index 78cf3d7dc835..0ca0bdbed1bd 100644
--- a/include/linux/kernel_read_file.h
+++ b/include/linux/kernel_read_file.h@@ -36,16 +36,16 @@ static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id) } int kernel_read_file(struct file *file, - void **buf, loff_t *size, loff_t max_size, + void **buf, loff_t max_size, enum kernel_read_file_id id); int kernel_read_file_from_path(const char *path, - void **buf, loff_t *size, loff_t max_size, + void **buf, loff_t max_size, enum kernel_read_file_id id); int kernel_read_file_from_path_initns(const char *path, - void **buf, loff_t *size, loff_t max_size, + void **buf, loff_t max_size, enum kernel_read_file_id id); int kernel_read_file_from_fd(int fd, - void **buf, loff_t *size, loff_t max_size, + void **buf, loff_t max_size, enum kernel_read_file_id id); #endif /* _LINUX_KERNEL_READ_FILE_H */
diff --git a/kernel/kexec_file.c b/kernel/kexec_file.c
index 1358069ce9e9..eda19ca256a3 100644
--- a/kernel/kexec_file.c
+++ b/kernel/kexec_file.c@@ -220,13 +220,12 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, { int ret; void *ldata; - loff_t size; ret = kernel_read_file_from_fd(kernel_fd, &image->kernel_buf, - &size, INT_MAX, READING_KEXEC_IMAGE); - if (ret) + INT_MAX, READING_KEXEC_IMAGE); + if (ret < 0) return ret; - image->kernel_buf_len = size; + image->kernel_buf_len = ret; /* Call arch image probe handlers */ ret = arch_kexec_kernel_image_probe(image, image->kernel_buf,
@@ -243,11 +242,12 @@ kimage_file_prepare_segments(struct kimage *image, int kernel_fd, int initrd_fd, /* It is possible that there no initramfs is being loaded */ if (!(flags & KEXEC_FILE_NO_INITRAMFS)) { ret = kernel_read_file_from_fd(initrd_fd, &image->initrd_buf, - &size, INT_MAX, + INT_MAX, READING_KEXEC_INITRAMFS); - if (ret) + if (ret < 0) goto out; - image->initrd_buf_len = size; + image->initrd_buf_len = ret; + ret = 0; } if (cmdline_len) {
diff --git a/kernel/module.c b/kernel/module.c
index e9765803601b..b6fd4f51cc30 100644
--- a/kernel/module.c
+++ b/kernel/module.c@@ -3988,7 +3988,6 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) { struct load_info info = { }; - loff_t size; void *hdr = NULL; int err;
@@ -4002,12 +4001,12 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) |MODULE_INIT_IGNORE_VERMAGIC)) return -EINVAL; - err = kernel_read_file_from_fd(fd, &hdr, &size, INT_MAX, + err = kernel_read_file_from_fd(fd, &hdr, INT_MAX, READING_MODULE); - if (err) + if (err < 0) return err; info.hdr = hdr; - info.len = size; + info.len = err; return load_module(&info, uargs, flags); }
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
index f8869be45d8f..97661ffabc4e 100644
--- a/security/integrity/digsig.c
+++ b/security/integrity/digsig.c@@ -171,16 +171,17 @@ int __init integrity_add_key(const unsigned int id, const void *data, int __init integrity_load_x509(const unsigned int id, const char *path) { void *data = NULL; - loff_t size; + size_t size; int rc; key_perm_t perm; - rc = kernel_read_file_from_path(path, &data, &size, 0, + rc = kernel_read_file_from_path(path, &data, 0, READING_X509_CERTIFICATE); if (rc < 0) { pr_err("Unable to open file: %s (%d)", path, rc); return rc; } + size = rc; perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ;
diff --git a/security/integrity/ima/ima_fs.c b/security/integrity/ima/ima_fs.c
index e13ffece3726..602f52717757 100644
--- a/security/integrity/ima/ima_fs.c
+++ b/security/integrity/ima/ima_fs.c@@ -275,7 +275,7 @@ static ssize_t ima_read_policy(char *path) { void *data = NULL; char *datap; - loff_t size; + size_t size; int rc, pathlen = strlen(path); char *p;
@@ -284,11 +284,13 @@ static ssize_t ima_read_policy(char *path) datap = path; strsep(&datap, "\n"); - rc = kernel_read_file_from_path(path, &data, &size, 0, READING_POLICY); + rc = kernel_read_file_from_path(path, &data, 0, READING_POLICY); if (rc < 0) { pr_err("Unable to open file: %s (%d)", path, rc); return rc; } + size = rc; + rc = 0; datap = data; while (size > 0 && (p = strsep(&datap, "\n"))) {
--
2.25.1