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| author | Richard Weinberger <richard@nod.at> | 2017-03-30 10:50:49 +0200 |
|---|---|---|
| committer | Richard Weinberger <richard@nod.at> | 2017-04-18 23:18:02 +0200 |
| commit | 32fe905c17f001c0eee13c59afddd0bf2eed509c (patch) | |
| tree | 2189b2fd37cf9faf6ca930581ae0c21c5fb1ab65 /fs/ubifs | |
| parent | c3d9fda688742c06e89aa1f0f8fd943fc11468cb (diff) | |
| download | linux-32fe905c17f001c0eee13c59afddd0bf2eed509c.tar.gz linux-32fe905c17f001c0eee13c59afddd0bf2eed509c.tar.bz2 linux-32fe905c17f001c0eee13c59afddd0bf2eed509c.zip | |
ubifs: Fix O_TMPFILE corner case in ubifs_link()
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: <stable@vger.kernel.org>
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>
Diffstat (limited to 'fs/ubifs')
| -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 0858213a4e63..b777bddaa1dd 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -748,6 +748,11 @@ static int ubifs_link(struct dentry *old_dentry, struct inode *dir, goto out_fname; 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); @@ -768,6 +773,8 @@ 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); |