diff options
Diffstat (limited to 'fs/fcntl.c')
-rw-r--r-- | fs/fcntl.c | 231 |
1 files changed, 138 insertions, 93 deletions
@@ -109,20 +109,34 @@ void __f_setown(struct file *filp, struct pid *pid, enum pid_type type, } EXPORT_SYMBOL(__f_setown); -void f_setown(struct file *filp, unsigned long arg, int force) +int f_setown(struct file *filp, unsigned long arg, int force) { enum pid_type type; - struct pid *pid; - int who = arg; + struct pid *pid = NULL; + int who = arg, ret = 0; + type = PIDTYPE_PID; if (who < 0) { + /* avoid overflow below */ + if (who == INT_MIN) + return -EINVAL; + type = PIDTYPE_PGID; who = -who; } + rcu_read_lock(); - pid = find_vpid(who); - __f_setown(filp, pid, type, force); + if (who) { + pid = find_vpid(who); + if (!pid) + ret = -ESRCH; + } + + if (!ret) + __f_setown(filp, pid, type, force); rcu_read_unlock(); + + return ret; } EXPORT_SYMBOL(f_setown); @@ -307,6 +321,8 @@ static long fcntl_rw_hint(struct file *file, unsigned int cmd, static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, struct file *filp) { + void __user *argp = (void __user *)arg; + struct flock flock; long err = -EINVAL; switch (cmd) { @@ -334,7 +350,11 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, case F_OFD_GETLK: #endif case F_GETLK: - err = fcntl_getlk(filp, cmd, (struct flock __user *) arg); + if (copy_from_user(&flock, argp, sizeof(flock))) + return -EFAULT; + err = fcntl_getlk(filp, cmd, &flock); + if (!err && copy_to_user(argp, &flock, sizeof(flock))) + return -EFAULT; break; #if BITS_PER_LONG != 32 /* 32-bit arches must use fcntl64() */ @@ -344,7 +364,9 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, /* Fallthrough */ case F_SETLK: case F_SETLKW: - err = fcntl_setlk(fd, filp, cmd, (struct flock __user *) arg); + if (copy_from_user(&flock, argp, sizeof(flock))) + return -EFAULT; + err = fcntl_setlk(fd, filp, cmd, &flock); break; case F_GETOWN: /* @@ -358,8 +380,7 @@ static long do_fcntl(int fd, unsigned int cmd, unsigned long arg, force_successful_syscall_return(); break; case F_SETOWN: - f_setown(filp, arg, 1); - err = 0; + err = f_setown(filp, arg, 1); break; case F_GETOWN_EX: err = f_getown_ex(filp, arg); @@ -450,7 +471,9 @@ out: SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, unsigned long, arg) { + void __user *argp = (void __user *)arg; struct fd f = fdget_raw(fd); + struct flock64 flock; long err = -EBADF; if (!f.file) @@ -468,14 +491,21 @@ SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, switch (cmd) { case F_GETLK64: case F_OFD_GETLK: - err = fcntl_getlk64(f.file, cmd, (struct flock64 __user *) arg); + err = -EFAULT; + if (copy_from_user(&flock, argp, sizeof(flock))) + break; + err = fcntl_getlk64(f.file, cmd, &flock); + if (!err && copy_to_user(argp, &flock, sizeof(flock))) + err = -EFAULT; break; case F_SETLK64: case F_SETLKW64: case F_OFD_SETLK: case F_OFD_SETLKW: - err = fcntl_setlk64(fd, f.file, cmd, - (struct flock64 __user *) arg); + err = -EFAULT; + if (copy_from_user(&flock, argp, sizeof(flock))) + break; + err = fcntl_setlk64(fd, f.file, cmd, &flock); break; default: err = do_fcntl(fd, cmd, arg, f.file); @@ -489,57 +519,56 @@ out: #endif #ifdef CONFIG_COMPAT +/* careful - don't use anywhere else */ +#define copy_flock_fields(from, to) \ + (to).l_type = (from).l_type; \ + (to).l_whence = (from).l_whence; \ + (to).l_start = (from).l_start; \ + (to).l_len = (from).l_len; \ + (to).l_pid = (from).l_pid; + static int get_compat_flock(struct flock *kfl, struct compat_flock __user *ufl) { - if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) || - __get_user(kfl->l_type, &ufl->l_type) || - __get_user(kfl->l_whence, &ufl->l_whence) || - __get_user(kfl->l_start, &ufl->l_start) || - __get_user(kfl->l_len, &ufl->l_len) || - __get_user(kfl->l_pid, &ufl->l_pid)) + struct compat_flock fl; + + if (copy_from_user(&fl, ufl, sizeof(struct compat_flock))) return -EFAULT; + copy_flock_fields(*kfl, fl); return 0; } -static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl) +static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl) { - if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) || - __put_user(kfl->l_type, &ufl->l_type) || - __put_user(kfl->l_whence, &ufl->l_whence) || - __put_user(kfl->l_start, &ufl->l_start) || - __put_user(kfl->l_len, &ufl->l_len) || - __put_user(kfl->l_pid, &ufl->l_pid)) + struct compat_flock64 fl; + + if (copy_from_user(&fl, ufl, sizeof(struct compat_flock64))) return -EFAULT; + copy_flock_fields(*kfl, fl); return 0; } -#ifndef HAVE_ARCH_GET_COMPAT_FLOCK64 -static int get_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl) +static int put_compat_flock(struct flock *kfl, struct compat_flock __user *ufl) { - if (!access_ok(VERIFY_READ, ufl, sizeof(*ufl)) || - __get_user(kfl->l_type, &ufl->l_type) || - __get_user(kfl->l_whence, &ufl->l_whence) || - __get_user(kfl->l_start, &ufl->l_start) || - __get_user(kfl->l_len, &ufl->l_len) || - __get_user(kfl->l_pid, &ufl->l_pid)) + struct compat_flock fl; + + memset(&fl, 0, sizeof(struct compat_flock)); + copy_flock_fields(fl, *kfl); + if (copy_to_user(ufl, &fl, sizeof(struct compat_flock))) return -EFAULT; return 0; } -#endif -#ifndef HAVE_ARCH_PUT_COMPAT_FLOCK64 static int put_compat_flock64(struct flock *kfl, struct compat_flock64 __user *ufl) { - if (!access_ok(VERIFY_WRITE, ufl, sizeof(*ufl)) || - __put_user(kfl->l_type, &ufl->l_type) || - __put_user(kfl->l_whence, &ufl->l_whence) || - __put_user(kfl->l_start, &ufl->l_start) || - __put_user(kfl->l_len, &ufl->l_len) || - __put_user(kfl->l_pid, &ufl->l_pid)) + struct compat_flock64 fl; + + memset(&fl, 0, sizeof(struct compat_flock64)); + copy_flock_fields(fl, *kfl); + if (copy_to_user(ufl, &fl, sizeof(struct compat_flock64))) return -EFAULT; return 0; } -#endif +#undef copy_flock_fields static unsigned int convert_fcntl_cmd(unsigned int cmd) @@ -556,76 +585,92 @@ convert_fcntl_cmd(unsigned int cmd) return cmd; } +/* + * GETLK was successful and we need to return the data, but it needs to fit in + * the compat structure. + * l_start shouldn't be too big, unless the original start + end is greater than + * COMPAT_OFF_T_MAX, in which case the app was asking for trouble, so we return + * -EOVERFLOW in that case. l_len could be too big, in which case we just + * truncate it, and only allow the app to see that part of the conflicting lock + * that might make sense to it anyway + */ +static int fixup_compat_flock(struct flock *flock) +{ + if (flock->l_start > COMPAT_OFF_T_MAX) + return -EOVERFLOW; + if (flock->l_len > COMPAT_OFF_T_MAX) + flock->l_len = COMPAT_OFF_T_MAX; + return 0; +} + COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd, compat_ulong_t, arg) { - mm_segment_t old_fs; - struct flock f; - long ret; - unsigned int conv_cmd; + struct fd f = fdget_raw(fd); + struct flock flock; + long err = -EBADF; + + if (!f.file) + return err; + + if (unlikely(f.file->f_mode & FMODE_PATH)) { + if (!check_fcntl_cmd(cmd)) + goto out_put; + } + + err = security_file_fcntl(f.file, cmd, arg); + if (err) + goto out_put; switch (cmd) { case F_GETLK: + err = get_compat_flock(&flock, compat_ptr(arg)); + if (err) + break; + err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock); + if (err) + break; + err = fixup_compat_flock(&flock); + if (err) + return err; + err = put_compat_flock(&flock, compat_ptr(arg)); + break; + case F_GETLK64: + case F_OFD_GETLK: + err = get_compat_flock64(&flock, compat_ptr(arg)); + if (err) + break; + err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock); + if (err) + break; + err = fixup_compat_flock(&flock); + if (err) + return err; + err = put_compat_flock64(&flock, compat_ptr(arg)); + break; case F_SETLK: case F_SETLKW: - ret = get_compat_flock(&f, compat_ptr(arg)); - if (ret != 0) + err = get_compat_flock(&flock, compat_ptr(arg)); + if (err) break; - old_fs = get_fs(); - set_fs(KERNEL_DS); - ret = sys_fcntl(fd, cmd, (unsigned long)&f); - set_fs(old_fs); - if (cmd == F_GETLK && ret == 0) { - /* GETLK was successful and we need to return the data... - * but it needs to fit in the compat structure. - * l_start shouldn't be too big, unless the original - * start + end is greater than COMPAT_OFF_T_MAX, in which - * case the app was asking for trouble, so we return - * -EOVERFLOW in that case. - * l_len could be too big, in which case we just truncate it, - * and only allow the app to see that part of the conflicting - * lock that might make sense to it anyway - */ - - if (f.l_start > COMPAT_OFF_T_MAX) - ret = -EOVERFLOW; - if (f.l_len > COMPAT_OFF_T_MAX) - f.l_len = COMPAT_OFF_T_MAX; - if (ret == 0) - ret = put_compat_flock(&f, compat_ptr(arg)); - } + err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock); break; - - case F_GETLK64: case F_SETLK64: case F_SETLKW64: - case F_OFD_GETLK: case F_OFD_SETLK: case F_OFD_SETLKW: - ret = get_compat_flock64(&f, compat_ptr(arg)); - if (ret != 0) + err = get_compat_flock64(&flock, compat_ptr(arg)); + if (err) break; - old_fs = get_fs(); - set_fs(KERNEL_DS); - conv_cmd = convert_fcntl_cmd(cmd); - ret = sys_fcntl(fd, conv_cmd, (unsigned long)&f); - set_fs(old_fs); - if ((conv_cmd == F_GETLK || conv_cmd == F_OFD_GETLK) && ret == 0) { - /* need to return lock information - see above for commentary */ - if (f.l_start > COMPAT_LOFF_T_MAX) - ret = -EOVERFLOW; - if (f.l_len > COMPAT_LOFF_T_MAX) - f.l_len = COMPAT_LOFF_T_MAX; - if (ret == 0) - ret = put_compat_flock64(&f, compat_ptr(arg)); - } + err = fcntl_setlk(fd, f.file, convert_fcntl_cmd(cmd), &flock); break; - default: - ret = sys_fcntl(fd, cmd, arg); + err = do_fcntl(fd, cmd, arg, f.file); break; } - return ret; +out_put: + fdput(f); + return err; } COMPAT_SYSCALL_DEFINE3(fcntl, unsigned int, fd, unsigned int, cmd, |