X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fexec.c;h=895823d0149d9cfbd75bb34b670662dafb7f9ef6;hb=8b6427a2a8f7dd43e9208fb33a3b116d66db4979;hp=07a059664b73084c59155ba5fe2ce69487e78210;hpb=498052bba55ecaff58db6a1436b0e25bfd75a7ff;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/exec.c b/fs/exec.c index 07a0596..895823d 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -53,6 +53,7 @@ #include #include #include +#include #include #include @@ -68,17 +69,18 @@ int suid_dumpable = 0; static LIST_HEAD(formats); static DEFINE_RWLOCK(binfmt_lock); -int register_binfmt(struct linux_binfmt * fmt) +int __register_binfmt(struct linux_binfmt * fmt, int insert) { if (!fmt) return -EINVAL; write_lock(&binfmt_lock); - list_add(&fmt->lh, &formats); + insert ? list_add(&fmt->lh, &formats) : + list_add_tail(&fmt->lh, &formats); write_unlock(&binfmt_lock); return 0; } -EXPORT_SYMBOL(register_binfmt); +EXPORT_SYMBOL(__register_binfmt); void unregister_binfmt(struct linux_binfmt * fmt) { @@ -103,40 +105,28 @@ static inline void put_binfmt(struct linux_binfmt * fmt) SYSCALL_DEFINE1(uselib, const char __user *, library) { struct file *file; - struct nameidata nd; char *tmp = getname(library); int error = PTR_ERR(tmp); - if (!IS_ERR(tmp)) { - error = path_lookup_open(AT_FDCWD, tmp, - LOOKUP_FOLLOW, &nd, - FMODE_READ|FMODE_EXEC); - putname(tmp); - } - if (error) + if (IS_ERR(tmp)) + goto out; + + file = do_filp_open(AT_FDCWD, tmp, + O_LARGEFILE | O_RDONLY | FMODE_EXEC, 0, + MAY_READ | MAY_EXEC | MAY_OPEN); + putname(tmp); + error = PTR_ERR(file); + if (IS_ERR(file)) goto out; error = -EINVAL; - if (!S_ISREG(nd.path.dentry->d_inode->i_mode)) + if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) goto exit; error = -EACCES; - if (nd.path.mnt->mnt_flags & MNT_NOEXEC) + if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) goto exit; - error = inode_permission(nd.path.dentry->d_inode, - MAY_READ | MAY_EXEC | MAY_OPEN); - if (error) - goto exit; - error = ima_path_check(&nd.path, MAY_READ | MAY_EXEC | MAY_OPEN); - if (error) - goto exit; - - file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE); - error = PTR_ERR(file); - if (IS_ERR(file)) - goto out; - fsnotify_open(file->f_path.dentry); error = -ENOEXEC; @@ -158,13 +148,10 @@ SYSCALL_DEFINE1(uselib, const char __user *, library) } read_unlock(&binfmt_lock); } +exit: fput(file); out: return error; -exit: - release_open_intent(&nd); - path_put(&nd.path); - goto out; } #ifdef CONFIG_MMU @@ -659,47 +646,33 @@ EXPORT_SYMBOL(setup_arg_pages); struct file *open_exec(const char *name) { - struct nameidata nd; struct file *file; int err; - err = path_lookup_open(AT_FDCWD, name, LOOKUP_FOLLOW, &nd, - FMODE_READ|FMODE_EXEC); - if (err) + file = do_filp_open(AT_FDCWD, name, + O_LARGEFILE | O_RDONLY | FMODE_EXEC, 0, + MAY_EXEC | MAY_OPEN); + if (IS_ERR(file)) goto out; err = -EACCES; - if (!S_ISREG(nd.path.dentry->d_inode->i_mode)) - goto out_path_put; - - if (nd.path.mnt->mnt_flags & MNT_NOEXEC) - goto out_path_put; - - err = inode_permission(nd.path.dentry->d_inode, MAY_EXEC | MAY_OPEN); - if (err) - goto out_path_put; - err = ima_path_check(&nd.path, MAY_EXEC | MAY_OPEN); - if (err) - goto out_path_put; + if (!S_ISREG(file->f_path.dentry->d_inode->i_mode)) + goto exit; - file = nameidata_to_filp(&nd, O_RDONLY|O_LARGEFILE); - if (IS_ERR(file)) - return file; + if (file->f_path.mnt->mnt_flags & MNT_NOEXEC) + goto exit; fsnotify_open(file->f_path.dentry); err = deny_write_access(file); - if (err) { - fput(file); - goto out; - } + if (err) + goto exit; +out: return file; - out_path_put: - release_open_intent(&nd); - path_put(&nd.path); - out: +exit: + fput(file); return ERR_PTR(err); } EXPORT_SYMBOL(open_exec); @@ -1059,32 +1032,29 @@ EXPORT_SYMBOL(install_exec_creds); int check_unsafe_exec(struct linux_binprm *bprm) { struct task_struct *p = current, *t; - unsigned long flags; - unsigned n_fs, n_sighand; + unsigned n_fs; int res = 0; bprm->unsafe = tracehook_unsafe_exec(p); n_fs = 1; - n_sighand = 1; write_lock(&p->fs->lock); - lock_task_sighand(p, &flags); + rcu_read_lock(); for (t = next_thread(p); t != p; t = next_thread(t)) { if (t->fs == p->fs) n_fs++; - n_sighand++; } + rcu_read_unlock(); - if (p->fs->users > n_fs || - atomic_read(&p->sighand->count) > n_sighand) { + if (p->fs->users > n_fs) { bprm->unsafe |= LSM_UNSAFE_SHARE; } else { - if (p->fs->in_exec) - res = -EAGAIN; - p->fs->in_exec = 1; + res = -EAGAIN; + if (!p->fs->in_exec) { + p->fs->in_exec = 1; + res = 1; + } } - - unlock_task_sighand(p, &flags); write_unlock(&p->fs->lock); return res; @@ -1286,6 +1256,7 @@ int do_execve(char * filename, struct linux_binprm *bprm; struct file *file; struct files_struct *displaced; + bool clear_in_exec; int retval; retval = unshare_files(&displaced); @@ -1308,8 +1279,9 @@ int do_execve(char * filename, goto out_unlock; retval = check_unsafe_exec(bprm); - if (retval) + if (retval < 0) goto out_unlock; + clear_in_exec = retval; file = open_exec(filename); retval = PTR_ERR(file); @@ -1357,9 +1329,7 @@ int do_execve(char * filename, goto out; /* execve succeeded */ - write_lock(¤t->fs->lock); current->fs->in_exec = 0; - write_unlock(¤t->fs->lock); current->in_execve = 0; mutex_unlock(¤t->cred_exec_mutex); acct_update_integrals(current); @@ -1379,9 +1349,8 @@ out_file: } out_unmark: - write_lock(¤t->fs->lock); - current->fs->in_exec = 0; - write_unlock(¤t->fs->lock); + if (clear_in_exec) + current->fs->in_exec = 0; out_unlock: current->in_execve = 0;