btrfs: return EINVAL if start > total_bytes in fitrim ioctl
We should retirn EINVAL if the start is beyond the end of the file
system in the btrfs_ioctl_fitrim(). Fix that by adding the appropriate
check for it.
Also in the btrfs_trim_fs() it is possible that len+start might overflow
if big values are passed. Fix it by decrementing the len so that start+len
is equal to the file system size in the worst case.
Signed-off-by: Lukas Czerner <lczerner@redhat.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index d524b66..136a2f9 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -282,6 +282,7 @@
struct fstrim_range range;
u64 minlen = ULLONG_MAX;
u64 num_devices = 0;
+ u64 total_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy);
int ret;
if (!capable(CAP_SYS_ADMIN))
@@ -300,12 +301,15 @@
}
}
rcu_read_unlock();
+
if (!num_devices)
return -EOPNOTSUPP;
-
if (copy_from_user(&range, arg, sizeof(range)))
return -EFAULT;
+ if (range.start > total_bytes)
+ return -EINVAL;
+ range.len = min(range.len, total_bytes - range.start);
range.minlen = max(range.minlen, minlen);
ret = btrfs_trim_fs(root, &range);
if (ret < 0)