The "inherit" in btrfs_ioctl_snap_create_v2() and "vol_args"
in
btrfs_ioctl_rm_dev() are ERR_PTRs so we can't call kfree() on them.
These kind of bugs are "One Err Bugs" where there is just one error
label that does everything. I could set the "inherit = NULL" and keep
the single out label but it ends up being more complicated that way. It
makes the code simpler to re-order the unwind so it's in the mirror
order of the allocation and introduce some new error labels.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index de505d5..741b92b 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1702,7 +1702,7 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file
*file,
~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY |
BTRFS_SUBVOL_QGROUP_INHERIT)) {
ret = -EOPNOTSUPP;
- goto out;
+ goto free_args;
}
if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
@@ -1712,27 +1712,31 @@ static noinline int btrfs_ioctl_snap_create_v2(struct
file *file,
if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) {
if (vol_args->size > PAGE_CACHE_SIZE) {
ret = -EINVAL;
- goto out;
+ goto free_args;
}
inherit = memdup_user(vol_args->qgroup_inherit, vol_args->size);
if (IS_ERR(inherit)) {
ret = PTR_ERR(inherit);
- goto out;
+ goto free_args;
}
}
ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
vol_args->fd, subvol, ptr,
readonly, inherit);
+ if (ret)
+ goto free_inherit;
- if (ret == 0 && ptr &&
- copy_to_user(arg +
- offsetof(struct btrfs_ioctl_vol_args_v2,
- transid), ptr, sizeof(*ptr)))
+ if (ptr && copy_to_user(arg +
+ offsetof(struct btrfs_ioctl_vol_args_v2,
+ transid),
+ ptr, sizeof(*ptr)))
ret = -EFAULT;
-out:
- kfree(vol_args);
+
+free_inherit:
kfree(inherit);
+free_args:
+ kfree(vol_args);
return ret;
}
@@ -2649,7 +2653,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void
__user *arg)
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args)) {
ret = PTR_ERR(vol_args);
- goto out;
+ goto err_drop;
}
vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
@@ -2667,6 +2671,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void
__user *arg)
out:
kfree(vol_args);
+err_drop:
mnt_drop_write_file(file);
return ret;
}
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