diff options
| -rw-r--r-- | fs/binfmt_misc.c | 41 |
1 files changed, 39 insertions, 2 deletions
diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c index 3a3ced779fc7..8a108c435bc6 100644 --- a/fs/binfmt_misc.c +++ b/fs/binfmt_misc.c @@ -26,6 +26,8 @@ #include <linux/fs.h> #include <linux/uaccess.h> +#include "internal.h" + #ifdef DEBUG # define USE_DEBUG 1 #else @@ -43,6 +45,7 @@ enum {Enabled, Magic}; #define MISC_FMT_PRESERVE_ARGV0 (1 << 31) #define MISC_FMT_OPEN_BINARY (1 << 30) #define MISC_FMT_CREDENTIALS (1 << 29) +#define MISC_FMT_OPEN_FILE (1 << 28) typedef struct { struct list_head list; @@ -54,6 +57,7 @@ typedef struct { char *interpreter; /* filename of interpreter */ char *name; struct dentry *dentry; + struct file *interp_file; } Node; static DEFINE_RWLOCK(entries_lock); @@ -201,7 +205,13 @@ static int load_misc_binary(struct linux_binprm *bprm) if (retval < 0) goto error; - interp_file = open_exec(iname); + if (fmt->flags & MISC_FMT_OPEN_FILE && fmt->interp_file) { + interp_file = filp_clone_open(fmt->interp_file); + if (!IS_ERR(interp_file)) + deny_write_access(interp_file); + } else { + interp_file = open_exec(iname); + } retval = PTR_ERR(interp_file); if (IS_ERR(interp_file)) goto error; @@ -285,6 +295,11 @@ static char *check_special_flags(char *sfs, Node *e) e->flags |= (MISC_FMT_CREDENTIALS | MISC_FMT_OPEN_BINARY); break; + case 'F': + pr_debug("register: flag: F: open interpreter file now\n"); + p++; + e->flags |= MISC_FMT_OPEN_FILE; + break; default: cont = 0; } @@ -543,6 +558,8 @@ static void entry_status(Node *e, char *page) *dp++ = 'O'; if (e->flags & MISC_FMT_CREDENTIALS) *dp++ = 'C'; + if (e->flags & MISC_FMT_OPEN_FILE) + *dp++ = 'F'; *dp++ = '\n'; if (!test_bit(Magic, &e->flags)) { @@ -590,6 +607,11 @@ static void kill_node(Node *e) } write_unlock(&entries_lock); + if ((e->flags & MISC_FMT_OPEN_FILE) && e->interp_file) { + filp_close(e->interp_file, NULL); + e->interp_file = NULL; + } + if (dentry) { drop_nlink(d_inode(dentry)); d_drop(dentry); @@ -698,6 +720,21 @@ static ssize_t bm_register_write(struct file *file, const char __user *buffer, goto out2; } + if (e->flags & MISC_FMT_OPEN_FILE) { + struct file *f; + + f = open_exec(e->interpreter); + if (IS_ERR(f)) { + err = PTR_ERR(f); + pr_notice("register: failed to install interpreter file %s\n", e->interpreter); + simple_release_fs(&bm_mnt, &entry_count); + iput(inode); + inode = NULL; + goto out2; + } + e->interp_file = f; + } + e->dentry = dget(dentry); inode->i_private = e; inode->i_fop = &bm_entry_operations; @@ -716,7 +753,7 @@ out: if (err) { kfree(e); - return -EINVAL; + return err; } return count; } |