From: Sungjong Seo sj1557.seo@samsung.com
commit 204e6ceaa1035cb7b92b156517e88842ebb4c7ff upstream.
In order for a file to access its own directory entry set, exfat_inode_info(ei) has two copied values. One is ei->dir, which is a snapshot of exfat_chain of the parent directory, and the other is ei->entry, which is the offset of the start of the directory entry set in the parent directory.
Since the parent directory can be updated after the snapshot point, it should be used only for accessing one's own directory entry set.
However, as of now, during renaming, it could try to traverse or to allocate clusters via snapshot values, it does not make sense.
This potential problem has been revealed when exfat_update_parent_info() was removed by commit d8dad2588add ("exfat: fix referencing wrong parent directory information after renaming"). However, I don't think it's good idea to bring exfat_update_parent_info() back.
Instead, let's use the updated exfat_chain of parent directory diectly.
Fixes: d8dad2588add ("exfat: fix referencing wrong parent directory information after renaming") Reported-by: Wang Yugui wangyugui@e16-tech.com Signed-off-by: Sungjong Seo sj1557.seo@samsung.com Tested-by: Wang Yugui wangyugui@e16-tech.com Signed-off-by: Namjae Jeon linkinjeon@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/exfat/namei.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/fs/exfat/namei.c +++ b/fs/exfat/namei.c @@ -1190,7 +1190,9 @@ static int __exfat_rename(struct inode * return -ENOENT; }
- exfat_chain_dup(&olddir, &ei->dir); + exfat_chain_set(&olddir, EXFAT_I(old_parent_inode)->start_clu, + EXFAT_B_TO_CLU_ROUND_UP(i_size_read(old_parent_inode), sbi), + EXFAT_I(old_parent_inode)->flags); dentry = ei->entry;
ep = exfat_get_dentry(sb, &olddir, dentry, &old_bh, NULL);