From: Dan Carpenter Date: Wed, 17 Feb 2021 06:04:34 +0000 (+0300) Subject: btrfs: validate qgroup inherit for SNAP_CREATE_V2 ioctl X-Git-Tag: accepted/tizen/unified/20230118.172025~7495^2~26 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=5011c5a663b9c6d6aff3d394f11049b371199627;p=platform%2Fkernel%2Flinux-rpi.git btrfs: validate qgroup inherit for SNAP_CREATE_V2 ioctl The problem is we're copying "inherit" from user space but we don't necessarily know that we're copying enough data for a 64 byte struct. Then the next problem is that 'inherit' has a variable size array at the end, and we have to verify that array is the size we expected. Fixes: 6f72c7e20dba ("Btrfs: add qgroup inheritance") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Dan Carpenter Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index a8c60d4..1b837c0 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1935,7 +1935,10 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file, if (vol_args->flags & BTRFS_SUBVOL_RDONLY) readonly = true; if (vol_args->flags & BTRFS_SUBVOL_QGROUP_INHERIT) { - if (vol_args->size > PAGE_SIZE) { + u64 nums; + + if (vol_args->size < sizeof(*inherit) || + vol_args->size > PAGE_SIZE) { ret = -EINVAL; goto free_args; } @@ -1944,6 +1947,20 @@ static noinline int btrfs_ioctl_snap_create_v2(struct file *file, ret = PTR_ERR(inherit); goto free_args; } + + if (inherit->num_qgroups > PAGE_SIZE || + inherit->num_ref_copies > PAGE_SIZE || + inherit->num_excl_copies > PAGE_SIZE) { + ret = -EINVAL; + goto free_inherit; + } + + nums = inherit->num_qgroups + 2 * inherit->num_ref_copies + + 2 * inherit->num_excl_copies; + if (vol_args->size != struct_size(inherit, qgroups, nums)) { + ret = -EINVAL; + goto free_inherit; + } } ret = __btrfs_ioctl_snap_create(file, vol_args->name, vol_args->fd,