diff options
Diffstat (limited to 'security')
| -rw-r--r-- | security/selinux/hooks.c | 73 |
1 files changed, 21 insertions, 52 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 6c77f63c759..651d8456611 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2088,15 +2088,19 @@ static int selinux_bprm_secureexec(struct linux_binprm *bprm) return (atsecure || cap_bprm_secureexec(bprm)); } +static int match_file(const void *p, struct file *file, unsigned fd) +{ + return file_has_perm(p, file, file_to_av(file)) ? fd + 1 : 0; +} + /* Derived from fs/exec.c:flush_old_files. */ static inline void flush_unauthorized_files(const struct cred *cred, struct files_struct *files) { struct file *file, *devnull = NULL; struct tty_struct *tty; - struct fdtable *fdt; - long j = -1; int drop_tty = 0; + unsigned n; tty = get_current_tty(); if (tty) { @@ -2123,58 +2127,23 @@ static inline void flush_unauthorized_files(const struct cred *cred, no_tty(); /* Revalidate access to inherited open files. */ - spin_lock(&files->file_lock); - for (;;) { - unsigned long set, i; - int fd; - - j++; - i = j * BITS_PER_LONG; - fdt = files_fdtable(files); - if (i >= fdt->max_fds) - break; - set = fdt->open_fds[j]; - if (!set) - continue; - spin_unlock(&files->file_lock); - for ( ; set ; i++, set >>= 1) { - if (set & 1) { - file = fget(i); - if (!file) - continue; - if (file_has_perm(cred, - file, - file_to_av(file))) { - sys_close(i); - fd = get_unused_fd(); - if (fd != i) { - if (fd >= 0) - put_unused_fd(fd); - fput(file); - continue; - } - if (devnull) { - get_file(devnull); - } else { - devnull = dentry_open( - &selinux_null, - O_RDWR, cred); - if (IS_ERR(devnull)) { - devnull = NULL; - put_unused_fd(fd); - fput(file); - continue; - } - } - fd_install(fd, devnull); - } - fput(file); - } - } - spin_lock(&files->file_lock); + n = iterate_fd(files, 0, match_file, cred); + if (!n) /* none found? */ + return; + devnull = dentry_open(&selinux_null, O_RDWR, cred); + if (!IS_ERR(devnull)) { + /* replace all the matching ones with this */ + do { + replace_fd(n - 1, get_file(devnull), 0); + } while ((n = iterate_fd(files, n, match_file, cred)) != 0); + fput(devnull); + } else { + /* just close all the matching ones */ + do { + replace_fd(n - 1, NULL, 0); + } while ((n = iterate_fd(files, n, match_file, cred)) != 0); } - spin_unlock(&files->file_lock); } /* |