[PATCH AUTOSEL 4.19 554/671] f2fs: fix to avoid accessing uninitialized field of inode page in is_alive()

Sasha Levin
2020-01-16T18:40:03Z

From: Chao Yu <yuchao0@huawei.com>

[ Upstream commit 98194030554cd9b10568a9b58f5a135c7e7cba85 ]

If inode is newly created, inode page may not synchronize with inode cache,
so fields like .i_inline or .i_extra_isize could be wrong, in below call
path, we may access such wrong fields, result in failing to migrate valid
target block.

Thread A Thread B
- f2fs_create
- f2fs_add_link
- f2fs_add_dentry
- f2fs_init_inode_metadata
- f2fs_add_inline_entry
- f2fs_new_inode_page
- f2fs_put_page
: inode page wasn't updated with inode cache
- gc_data_segment
- is_alive
- f2fs_get_node_page
- datablock_addr
- offset_in_addr
: access uninitialized fields

Fixes: 7a2af766af15 ("f2fs: enhance on-disk inode structure scalability")
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/dir.c | 5 +++++
fs/f2fs/inline.c | 5 +++++
2 files changed, 10 insertions(+)

diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index cd611a57d04d..8692cfa89a1c 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -572,6 +572,11 @@ int f2fs_add_regular_entry(struct inode *dir, const struct qstr *new_name,

if (inode) {
f2fs_i_pino_write(inode, dir->i_ino);
+
+ /* synchronize inode page's data from inode cache */
+ if (is_inode_flag_set(inode, FI_NEW_INODE))
+ f2fs_update_inode(inode, page);
+
f2fs_put_page(page, 1);
}

diff --git a/fs/f2fs/inline.c b/fs/f2fs/inline.c
index 3fe0dd531390..c1ba29d10789 100644
--- a/fs/f2fs/inline.c
+++ b/fs/f2fs/inline.c
@@ -578,6 +578,11 @@ int f2fs_add_inline_entry(struct inode *dir, const struct qstr *new_name,
/* we don't need to mark_inode_dirty now */
if (inode) {
f2fs_i_pino_write(inode, dir->i_ino);
+
+ /* synchronize inode page's data from inode cache */
+ if (is_inode_flag_set(inode, FI_NEW_INODE))
+ f2fs_update_inode(inode, page);
+
f2fs_put_page(page, 1);
}

--
2.20.1