From: Qu Wenruo Date: Thu, 6 Apr 2023 05:00:34 +0000 (+0800) Subject: btrfs: scrub: reject unsupported scrub flags X-Git-Tag: v6.4-rc1~141^2~6 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=604e6681e114d05a2e384c4d1e8ef81918037ef5;p=thirdparty%2Fkernel%2Flinux.git btrfs: scrub: reject unsupported scrub flags Since the introduction of scrub interface, the only flag that we support is BTRFS_SCRUB_READONLY. Thus there is no sanity checks, if there are some undefined flags passed in, we just ignore them. This is problematic if we want to introduce new scrub flags, as we have no way to determine if such flags are supported. Address the problem by introducing a check for the flags, and if unsupported flags are set, return -EOPNOTSUPP to inform the user space. This check should be backported for all supported kernels before any new scrub flags are introduced. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Anand Jain Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index ba769a1eb87ab..25833b4eeaf57 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -3161,6 +3161,11 @@ static long btrfs_ioctl_scrub(struct file *file, void __user *arg) if (IS_ERR(sa)) return PTR_ERR(sa); + if (sa->flags & ~BTRFS_SCRUB_SUPPORTED_FLAGS) { + ret = -EOPNOTSUPP; + goto out; + } + if (!(sa->flags & BTRFS_SCRUB_READONLY)) { ret = mnt_want_write_file(file); if (ret) diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h index ada0a489bf2b6..dbb8b96da50d3 100644 --- a/include/uapi/linux/btrfs.h +++ b/include/uapi/linux/btrfs.h @@ -187,6 +187,7 @@ struct btrfs_scrub_progress { }; #define BTRFS_SCRUB_READONLY 1 +#define BTRFS_SCRUB_SUPPORTED_FLAGS (BTRFS_SCRUB_READONLY) struct btrfs_ioctl_scrub_args { __u64 devid; /* in */ __u64 start; /* in */