releases/5.9.5/f2fs-do-sanity-check-on-zoned-block-device-path.patch

From 0ecef49d576463df188050198f453ccb0ff385d5 Mon Sep 17 00:00:00 2001
From: Sasha Levin <sashal@kernel.org>
Date: Mon, 21 Sep 2020 20:53:13 +0800
Subject: f2fs: do sanity check on zoned block device path

From: Chao Yu <yuchao0@huawei.com>

[ Upstream commit 07eb1d699452de04e9d389ff17fb8fc9e975d7bf ]

sbi->devs would be initialized only if image enables multiple device
feature or blkzoned feature, if blkzoned feature flag was set by fuzz
in non-blkzoned device, we will suffer below panic:

get_zone_idx fs/f2fs/segment.c:4892 [inline]
f2fs_usable_zone_blks_in_seg fs/f2fs/segment.c:4943 [inline]
f2fs_usable_blks_in_seg+0x39b/0xa00 fs/f2fs/segment.c:4999
Call Trace:
 check_block_count+0x69/0x4e0 fs/f2fs/segment.h:704
 build_sit_entries fs/f2fs/segment.c:4403 [inline]
 f2fs_build_segment_manager+0x51da/0xa370 fs/f2fs/segment.c:5100
 f2fs_fill_super+0x3880/0x6ff0 fs/f2fs/super.c:3684
 mount_bdev+0x32e/0x3f0 fs/super.c:1417
 legacy_get_tree+0x105/0x220 fs/fs_context.c:592
 vfs_get_tree+0x89/0x2f0 fs/super.c:1547
 do_new_mount fs/namespace.c:2896 [inline]
 path_mount+0x12ae/0x1e70 fs/namespace.c:3216
 do_mount fs/namespace.c:3229 [inline]
 __do_sys_mount fs/namespace.c:3437 [inline]
 __se_sys_mount fs/namespace.c:3414 [inline]
 __x64_sys_mount+0x27f/0x300 fs/namespace.c:3414
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46

Add sanity check to inconsistency on factors: blkzoned flag, device
path and device character to avoid above panic.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/super.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index dfa072fa80815..be5050292caa5 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -2832,6 +2832,12 @@ static int sanity_check_raw_super(struct f2fs_sb_info *sbi,
 					segment_count, dev_seg_count);
 			return -EFSCORRUPTED;
 		}
+	} else {
+		if (__F2FS_HAS_FEATURE(raw_super, F2FS_FEATURE_BLKZONED) &&
+					!bdev_is_zoned(sbi->sb->s_bdev)) {
+			f2fs_info(sbi, "Zoned block device path is missing");
+			return -EFSCORRUPTED;
+		}
 	}
 
 	if (secs_per_zone > total_sections || !secs_per_zone) {
-- 
2.27.0