[PATCH 5.19 116/717] f2fs: fix to do sanity check on destination blkaddr during recovery

Greg Kroah-Hartman
2022-10-22T07:46:45Z

From: Chao Yu <chao@kernel.org>

commit 0ef4ca04a3f9223ff8bc440041c524b2123e09a3 upstream.

As Wenqing Liu reported in bugzilla:

https://bugzilla.kernel.org/show_bug.cgi?id=216456

loop5: detected capacity change from 0 to 131072
F2FS-fs (loop5): recover_inode: ino = 6, name = hln, inline = 1
F2FS-fs (loop5): recover_data: ino = 6 (i_size: recover) err = 0
F2FS-fs (loop5): recover_inode: ino = 6, name = hln, inline = 1
F2FS-fs (loop5): recover_data: ino = 6 (i_size: recover) err = 0
F2FS-fs (loop5): recover_inode: ino = 6, name = hln, inline = 1
F2FS-fs (loop5): recover_data: ino = 6 (i_size: recover) err = 0
F2FS-fs (loop5): Bitmap was wrongly set, blk:5634
------------[ cut here ]------------
WARNING: CPU: 3 PID: 1013 at fs/f2fs/segment.c:2198
RIP: 0010:update_sit_entry+0xa55/0x10b0 [f2fs]
Call Trace:
<TASK>
f2fs_do_replace_block+0xa98/0x1890 [f2fs]
f2fs_replace_block+0xeb/0x180 [f2fs]
recover_data+0x1a69/0x6ae0 [f2fs]
f2fs_recover_fsync_data+0x120d/0x1fc0 [f2fs]
f2fs_fill_super+0x4665/0x61e0 [f2fs]
mount_bdev+0x2cf/0x3b0
legacy_get_tree+0xed/0x1d0
vfs_get_tree+0x81/0x2b0
path_mount+0x47e/0x19d0
do_mount+0xce/0xf0
__x64_sys_mount+0x12c/0x1a0
do_syscall_64+0x38/0x90
entry_SYSCALL_64_after_hwframe+0x63/0xcd

If we enable CONFIG_F2FS_CHECK_FS config, it will trigger a kernel panic
instead of warning.

The root cause is: in fuzzed image, SIT table is inconsistent with inode
mapping table, result in triggering such warning during SIT table update.

This patch introduces a new flag DATA_GENERIC_ENHANCE_UPDATE, w/ this
flag, data block recovery flow can check destination blkaddr's validation
in SIT table, and skip f2fs_replace_block() to avoid inconsistent status.

Cc: stable@vger.kernel.org
Reported-by: Wenqing Liu <wenqingliu0120@gmail.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/f2fs/checkpoint.c | 10 +++++++++-
fs/f2fs/f2fs.h | 4 ++++
fs/f2fs/recovery.c | 8 ++++++++
3 files changed, 21 insertions(+), 1 deletion(-)

--- a/fs/f2fs/checkpoint.c
+++ b/fs/f2fs/checkpoint.c
@@ -140,7 +140,7 @@ static bool __is_bitmap_valid(struct f2f
unsigned int segno, offset;
bool exist;

- if (type != DATA_GENERIC_ENHANCE && type != DATA_GENERIC_ENHANCE_READ)
+ if (type == DATA_GENERIC)
return true;

segno = GET_SEGNO(sbi, blkaddr);
@@ -148,6 +148,13 @@ static bool __is_bitmap_valid(struct f2f
se = get_seg_entry(sbi, segno);

exist = f2fs_test_bit(offset, se->cur_valid_map);
+ if (exist && type == DATA_GENERIC_ENHANCE_UPDATE) {
+ f2fs_err(sbi, "Inconsistent error blkaddr:%u, sit bitmap:%d",
+ blkaddr, exist);
+ set_sbi_flag(sbi, SBI_NEED_FSCK);
+ return exist;
+ }
+
if (!exist && type == DATA_GENERIC_ENHANCE) {
f2fs_err(sbi, "Inconsistent error blkaddr:%u, sit bitmap:%d",
blkaddr, exist);
@@ -185,6 +192,7 @@ bool f2fs_is_valid_blkaddr(struct f2fs_s
case DATA_GENERIC:
case DATA_GENERIC_ENHANCE:
case DATA_GENERIC_ENHANCE_READ:
+ case DATA_GENERIC_ENHANCE_UPDATE:
if (unlikely(blkaddr >= MAX_BLKADDR(sbi) ||
blkaddr < MAIN_BLKADDR(sbi))) {
f2fs_warn(sbi, "access invalid blkaddr:%u",
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -266,6 +266,10 @@ enum {
* condition of read on truncated area
* by extent_cache
*/
+ DATA_GENERIC_ENHANCE_UPDATE, /*
+ * strong check on range and segment
+ * bitmap for update case
+ */
META_GENERIC,
};

--- a/fs/f2fs/recovery.c
+++ b/fs/f2fs/recovery.c
@@ -698,6 +698,14 @@ retry_prev:
goto err;
}

+ if (f2fs_is_valid_blkaddr(sbi, dest,
+ DATA_GENERIC_ENHANCE_UPDATE)) {
+ f2fs_err(sbi, "Inconsistent dest blkaddr:%u, ino:%lu, ofs:%u",
+ dest, inode->i_ino, dn.ofs_in_node);
+ err = -EFSCORRUPTED;
+ goto err;
+ }
+
/* write dummy data page */
f2fs_replace_block(sbi, &dn, src, dest,
ni.version, false, false);