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Diffstat (limited to 'fs/fcntl.c')
-rw-r--r--fs/fcntl.c145
1 files changed, 89 insertions, 56 deletions
diff --git a/fs/fcntl.c b/fs/fcntl.c
index f4e7267d117f..bbf80344c125 100644
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -246,6 +246,8 @@ static int f_getowner_uids(struct file *filp, unsigned long arg)
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) {
@@ -273,7 +275,11 @@ 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() */
@@ -283,7 +289,9 @@ 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:
/*
@@ -383,7 +391,9 @@ 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)
@@ -401,14 +411,21 @@ 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);
@@ -489,76 +506,92 @@ 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,
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-31 10:58:40 +0000