diff options
Diffstat (limited to 'kernel/module/main.c')
| -rw-r--r-- | kernel/module/main.c | 58 |
1 files changed, 43 insertions, 15 deletions
diff --git a/kernel/module/main.c b/kernel/module/main.c index 044aa2c9e3cb..b4c7e925fdb0 100644 --- a/kernel/module/main.c +++ b/kernel/module/main.c @@ -3057,25 +3057,13 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, return load_module(&info, uargs, 0); } -SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) +static int file_init_module(struct file *file, const char __user * uargs, int flags) { struct load_info info = { }; void *buf = NULL; int len; - int err; - - err = may_init_module(); - if (err) - return err; - - pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags); - if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS - |MODULE_INIT_IGNORE_VERMAGIC - |MODULE_INIT_COMPRESSED_FILE)) - return -EINVAL; - - len = kernel_read_file_from_fd(fd, 0, &buf, INT_MAX, NULL, + len = kernel_read_file(file, 0, &buf, INT_MAX, NULL, READING_MODULE); if (len < 0) { mod_stat_inc(&failed_kreads); @@ -3084,7 +3072,7 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) } if (flags & MODULE_INIT_COMPRESSED_FILE) { - err = module_decompress(&info, buf, len); + int err = module_decompress(&info, buf, len); vfree(buf); /* compressed data is no longer needed */ if (err) { mod_stat_inc(&failed_decompress); @@ -3099,6 +3087,46 @@ SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) return load_module(&info, uargs, flags); } +/* + * kernel_read_file() will already deny write access, but module + * loading wants _exclusive_ access to the file, so we do that + * here, along with basic sanity checks. + */ +static int prepare_file_for_module_load(struct file *file) +{ + if (!file || !(file->f_mode & FMODE_READ)) + return -EBADF; + if (!S_ISREG(file_inode(file)->i_mode)) + return -EINVAL; + return exclusive_deny_write_access(file); +} + +SYSCALL_DEFINE3(finit_module, int, fd, const char __user *, uargs, int, flags) +{ + struct fd f; + int err; + + err = may_init_module(); + if (err) + return err; + + pr_debug("finit_module: fd=%d, uargs=%p, flags=%i\n", fd, uargs, flags); + + if (flags & ~(MODULE_INIT_IGNORE_MODVERSIONS + |MODULE_INIT_IGNORE_VERMAGIC + |MODULE_INIT_COMPRESSED_FILE)) + return -EINVAL; + + f = fdget(fd); + err = prepare_file_for_module_load(f.file); + if (!err) { + err = file_init_module(f.file, uargs, flags); + allow_write_access(f.file); + } + fdput(f); + return err; +} + /* Keep in sync with MODULE_FLAGS_BUF_SIZE !!! */ char *module_flags(struct module *mod, char *buf, bool show_state) { |