On Wed, 2003-05-07 at 06:50, viroat_private wrote: > Umm... How about having it merged with proc_base_readdir()? I.e. > have both call the common helper. Ditto for lookups. > > Other than that (and missing check for copy_to_user() return value in > ->read()) I don't see any problems here. This updated patch against 2.5.69 merges the readdir and lookup routines for proc_base and proc_attr, fixes the copy_to_user call in proc_attr_read and proc_info_read, moves the new data and code within CONFIG_SECURITY, and uses ARRAY_SIZE, per the comments from Al Viro and Andrew Morton. As before, this patch implements a process attribute API for security modules via a set of nodes in a /proc/pid/attr directory. Credit for the idea of implementing this API via /proc/pid/attr nodes goes to Al Viro. Jan Harkes provided a nice cleanup of the implementation to reduce the code bloat. fs/proc/base.c | 172 +++++++++++++++++++++++++++++++++++++++++++---- include/linux/security.h | 23 ++++++ security/dummy.c | 12 +++ 3 files changed, 196 insertions(+), 11 deletions(-) Index: linux-2.5/fs/proc/base.c diff -u linux-2.5/fs/proc/base.c:1.1.1.3 linux-2.5/fs/proc/base.c:1.10 --- linux-2.5/fs/proc/base.c:1.1.1.3 Mon Apr 21 10:15:46 2003 +++ linux-2.5/fs/proc/base.c Wed May 7 10:53:05 2003 @@ -58,6 +58,13 @@ PROC_PID_MAPS, PROC_PID_MOUNTS, PROC_PID_WCHAN, +#ifdef CONFIG_SECURITY + PROC_PID_ATTR, + PROC_PID_ATTR_CURRENT, + PROC_PID_ATTR_PREV, + PROC_PID_ATTR_EXEC, + PROC_PID_ATTR_FSCREATE, +#endif PROC_PID_FD_DIR = 0x8000, /* 0x8000-0xffff */ }; @@ -82,11 +89,23 @@ E(PROC_PID_ROOT, "root", S_IFLNK|S_IRWXUGO), E(PROC_PID_EXE, "exe", S_IFLNK|S_IRWXUGO), E(PROC_PID_MOUNTS, "mounts", S_IFREG|S_IRUGO), +#ifdef CONFIG_SECURITY + E(PROC_PID_ATTR, "attr", S_IFDIR|S_IRUGO|S_IXUGO), +#endif #ifdef CONFIG_KALLSYMS E(PROC_PID_WCHAN, "wchan", S_IFREG|S_IRUGO), #endif {0,0,NULL,0} }; +#ifdef CONFIG_SECURITY +static struct pid_entry attr_stuff[] = { + E(PROC_PID_ATTR_CURRENT, "current", S_IFREG|S_IRUGO|S_IWUSR), + E(PROC_PID_ATTR_PREV, "prev", S_IFREG|S_IRUGO|S_IWUSR), + E(PROC_PID_ATTR_EXEC, "exec", S_IFREG|S_IRUGO|S_IWUSR), + E(PROC_PID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUSR), + {0,0,NULL,0} +}; +#endif #undef E static inline struct task_struct *proc_task(struct inode *inode) @@ -409,8 +428,10 @@ if (count + *ppos > length) count = length - *ppos; end = count + *ppos; - copy_to_user(buf, (char *) page + *ppos, count); - *ppos = end; + if (copy_to_user(buf, (char *) page + *ppos, count)) + count = -EFAULT; + else + *ppos = end; free_page(page); return count; } @@ -687,14 +708,17 @@ return retval; } -static int proc_base_readdir(struct file * filp, - void * dirent, filldir_t filldir) +static int proc_pident_readdir(struct file * filp, + void * dirent, filldir_t filldir, + struct pid_entry *ents, unsigned int nents) { int i; int pid; - struct inode *inode = filp->f_dentry->d_inode; + struct dentry *dentry = filp->f_dentry; + struct inode *inode = dentry->d_inode; struct pid_entry *p; int ret = 0; + ino_t ino; lock_kernel(); @@ -706,24 +730,26 @@ i = filp->f_pos; switch (i) { case 0: - if (filldir(dirent, ".", 1, i, inode->i_ino, DT_DIR) < 0) + ino = inode->i_ino; + if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) goto out; i++; filp->f_pos++; /* fall through */ case 1: - if (filldir(dirent, "..", 2, i, PROC_ROOT_INO, DT_DIR) < 0) + ino = parent_ino(dentry); + if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) goto out; i++; filp->f_pos++; /* fall through */ default: i -= 2; - if (i>=sizeof(base_stuff)/sizeof(base_stuff[0])) { + if (i>=nents) { ret = 1; goto out; } - p = base_stuff + i; + p = ents + i; while (p->name) { if (filldir(dirent, p->name, p->len, filp->f_pos, fake_ino(pid, p->type), p->mode >> 12) < 0) @@ -739,6 +765,13 @@ return ret; } +static int proc_base_readdir(struct file * filp, + void * dirent, filldir_t filldir) +{ + return proc_pident_readdir(filp,dirent,filldir, + base_stuff,ARRAY_SIZE(base_stuff)); +} + /* building an inode */ static int task_dumpable(struct task_struct *task) @@ -961,8 +994,86 @@ .permission = proc_permission, }; +#ifdef CONFIG_SECURITY +static ssize_t proc_pid_attr_read(struct file * file, char * buf, + size_t count, loff_t *ppos) +{ + struct inode * inode = file->f_dentry->d_inode; + unsigned long page; + ssize_t length; + ssize_t end; + struct task_struct *task = proc_task(inode); + + if (count > PAGE_SIZE) + count = PAGE_SIZE; + if (!(page = __get_free_page(GFP_KERNEL))) + return -ENOMEM; + + length = security_getprocattr(task, + (char*)file->f_dentry->d_name.name, + (void*)page, count); + if (length < 0) { + free_page(page); + return length; + } + /* Static 4kB (or whatever) block capacity */ + if (*ppos >= length) { + free_page(page); + return 0; + } + if (count + *ppos > length) + count = length - *ppos; + end = count + *ppos; + if (copy_to_user(buf, (char *) page + *ppos, count)) + count = -EFAULT; + else + *ppos = end; + free_page(page); + return count; +} + +static ssize_t proc_pid_attr_write(struct file * file, const char * buf, + size_t count, loff_t *ppos) +{ + struct inode * inode = file->f_dentry->d_inode; + char *page; + ssize_t length; + struct task_struct *task = proc_task(inode); + + if (count > PAGE_SIZE) + count = PAGE_SIZE; + if (*ppos != 0) { + /* No partial writes. */ + return -EINVAL; + } + page = (char*)__get_free_page(GFP_USER); + if (!page) + return -ENOMEM; + length = -EFAULT; + if (copy_from_user(page, buf, count)) + goto out; + + length = security_setprocattr(task, + (char*)file->f_dentry->d_name.name, + (void*)page, count); +out: + free_page((unsigned long) page); + return length; +} + +static struct file_operations proc_pid_attr_operations = { + .read = proc_pid_attr_read, + .write = proc_pid_attr_write, +}; + +static struct file_operations proc_attr_operations; +static struct inode_operations proc_attr_inode_operations; +#endif + /* SMP-safe */ -static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry) +static struct dentry *proc_pident_lookup(struct inode *dir, + struct dentry *dentry, + struct pid_entry *ents) { struct inode *inode; int error; @@ -973,7 +1084,7 @@ error = -ENOENT; inode = NULL; - for (p = base_stuff; p->name; p++) { + for (p = ents; p->name; p++) { if (p->len != dentry->d_name.len) continue; if (!memcmp(dentry->d_name.name, p->name, p->len)) @@ -1041,6 +1152,19 @@ case PROC_PID_MOUNTS: inode->i_fop = &proc_mounts_operations; break; +#ifdef CONFIG_SECURITY + case PROC_PID_ATTR: + inode->i_nlink = 2; + inode->i_op = &proc_attr_inode_operations; + inode->i_fop = &proc_attr_operations; + break; + case PROC_PID_ATTR_CURRENT: + case PROC_PID_ATTR_PREV: + case PROC_PID_ATTR_EXEC: + case PROC_PID_ATTR_FSCREATE: + inode->i_fop = &proc_pid_attr_operations; + break; +#endif #ifdef CONFIG_KALLSYMS case PROC_PID_WCHAN: inode->i_fop = &proc_info_file_operations; @@ -1062,6 +1186,10 @@ return ERR_PTR(error); } +static struct dentry *proc_base_lookup(struct inode *dir, struct dentry *dentry){ + return proc_pident_lookup(dir, dentry, base_stuff); +} + static struct file_operations proc_base_operations = { .read = generic_read_dir, .readdir = proc_base_readdir, @@ -1070,6 +1198,28 @@ static struct inode_operations proc_base_inode_operations = { .lookup = proc_base_lookup, }; + +#ifdef CONFIG_SECURITY +static int proc_attr_readdir(struct file * filp, + void * dirent, filldir_t filldir) +{ + return proc_pident_readdir(filp,dirent,filldir, + attr_stuff,ARRAY_SIZE(attr_stuff)); +} + +static struct file_operations proc_attr_operations = { + .read = generic_read_dir, + .readdir = proc_attr_readdir, +}; + +static struct dentry *proc_attr_lookup(struct inode *dir, struct dentry *dentry){ + return proc_pident_lookup(dir, dentry, attr_stuff); +} + +static struct inode_operations proc_attr_inode_operations = { + .lookup = proc_attr_lookup, +}; +#endif /* * /proc/self: Index: linux-2.5/include/linux/security.h diff -u linux-2.5/include/linux/security.h:1.1.1.2 linux-2.5/include/linux/security.h:1.16 --- linux-2.5/include/linux/security.h:1.1.1.2 Wed Mar 19 09:54:58 2003 +++ linux-2.5/include/linux/security.h Fri Apr 18 11:17:19 2003 @@ -1123,6 +1128,9 @@ void (*d_instantiate) (struct dentry *dentry, struct inode *inode); + int (*getprocattr)(struct task_struct *p, char *name, void *value, size_t size); + int (*setprocattr)(struct task_struct *p, char *name, void *value, size_t size); + #ifdef CONFIG_SECURITY_NETWORK int (*unix_stream_connect) (struct socket * sock, struct socket * other, struct sock * newsk); @@ -1755,6 +1769,16 @@ security_ops->d_instantiate (dentry, inode); } +static inline int security_getprocattr(struct task_struct *p, char *name, void *value, size_t size) +{ + return security_ops->getprocattr(p, name, value, size); +} + +static inline int security_setprocattr(struct task_struct *p, char *name, void *value, size_t size) +{ + return security_ops->setprocattr(p, name, value, size); +} + static inline int security_netlink_send(struct sk_buff * skb) { return security_ops->netlink_send(skb); @@ -2339,6 +2367,16 @@ static inline void security_d_instantiate (struct dentry *dentry, struct inode *inode) { } + +static inline int security_getprocattr(struct task_struct *p, char *name, void *value, size_t size) +{ + return -EINVAL; +} + +static inline int security_setprocattr(struct task_struct *p, char *name, void *value, size_t size) +{ + return -EINVAL; +} /* * The netlink capability defaults need to be used inline by default Index: linux-2.5/security/dummy.c diff -u linux-2.5/security/dummy.c:1.1.1.2 linux-2.5/security/dummy.c:1.14 --- linux-2.5/security/dummy.c:1.1.1.2 Wed Mar 19 09:59:17 2003 +++ linux-2.5/security/dummy.c Fri Apr 18 11:17:20 2003 @@ -736,6 +741,16 @@ return; } +static int dummy_getprocattr(struct task_struct *p, char *name, void *value, size_t size) +{ + return -EINVAL; +} + +static int dummy_setprocattr(struct task_struct *p, char *name, void *value, size_t size) +{ + return -EINVAL; +} + struct security_operations dummy_security_ops; @@ -860,6 +876,8 @@ set_to_dummy_if_null(ops, register_security); set_to_dummy_if_null(ops, unregister_security); set_to_dummy_if_null(ops, d_instantiate); + set_to_dummy_if_null(ops, getprocattr); + set_to_dummy_if_null(ops, setprocattr); #ifdef CONFIG_SECURITY_NETWORK set_to_dummy_if_null(ops, unix_stream_connect); set_to_dummy_if_null(ops, unix_may_send); -- Stephen Smalley <sdsat_private> National Security Agency _______________________________________________ linux-security-module mailing list linux-security-moduleat_private http://mail.wirex.com/mailman/listinfo/linux-security-module
This archive was generated by hypermail 2b30 : Wed May 07 2003 - 08:04:29 PDT