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| author | Richard Weinberger <richard@nod.at> | 2017-03-30 08:50:49 (GMT) |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-04-27 07:10:38 (GMT) |
| commit | b93858556fd13c76a36a0c110450fa35eadf5671 (patch) | |
| tree | 415a9544fdce6f43350337c91f62d5abfe3e7af9 /fs | |
| parent | a260ff509b4d5fde2ac5f863cd3015cefbc45189 (diff) | |
| download | linux-b93858556fd13c76a36a0c110450fa35eadf5671.tar.xz | |
ubifs: Fix O_TMPFILE corner case in ubifs_link()
commit 32fe905c17f001c0eee13c59afddd0bf2eed509c upstream.
It is perfectly fine to link a tmpfile back using linkat().
Since tmpfiles are created with a link count of 0 they appear
on the orphan list, upon re-linking the inode has to be removed
from the orphan list again.
Ralph faced a filesystem corruption in combination with overlayfs
due to this bug.
Cc: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Reported-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Tested-by: Ralph Sennhauser <ralph.sennhauser@gmail.com>
Reported-by: Amir Goldstein <amir73il@gmail.com>
Fixes: 474b93704f321 ("ubifs: Implement O_TMPFILE")
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ubifs/dir.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 0b5a19d..87ab02e 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -622,6 +622,11 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir, return err; lock_2_inodes(dir, inode); + + /* Handle O_TMPFILE corner case, it is allowed to link a O_TMPFILE. */ + if (inode->i_nlink == 0) + ubifs_delete_orphan(c, inode->i_ino); + inc_nlink(inode); ihold(inode); inode->i_ctime = ubifs_current_time(inode); @@ -641,6 +646,8 @@ out_cancel: dir->i_size -= sz_change; dir_ui->ui_size = dir->i_size; drop_nlink(inode); + if (inode->i_nlink == 0) + ubifs_add_orphan(c, inode->i_ino); unlock_2_inodes(dir, inode); ubifs_release_budget(c, &req); iput(inode); |