diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2011-03-04 13:14:21 -0500 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-03-04 13:14:21 -0500 |
| commit | 1858efd471624ecb37e6b5462cab8076f47d1cee (patch) | |
| tree | 29d1e5d2aad63b798e880011fc527bb4bab63e40 | |
| parent | b65a0e0c84cf489bfa00d6aa6c48abc5a237100f (diff) | |
minimal fix for do_filp_open() race
failure exits on the no-O_CREAT side of do_filp_open() merge with
those of O_CREAT one; unfortunately, if do_path_lookup() returns
-ESTALE, we'll get out_filp:, notice that we are about to return
-ESTALE without having trying to create the sucker with LOOKUP_REVAL
and jump right into the O_CREAT side of code. And proceed to try
and create a file. Usually that'll fail with -ESTALE again, but
we can race and get that attempt of pathname resolution to succeed.
open() without O_CREAT really shouldn't end up creating files, races
or not. The real fix is to rearchitect the whole do_filp_open(),
but for now splitting the failure exits will do.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/namei.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/namei.c b/fs/namei.c index 0087cf9c2c6b..a5e844fe4b28 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2455,22 +2455,29 @@ struct file *do_filp_open(int dfd, const char *pathname, /* !O_CREAT, simple open */ error = do_path_lookup(dfd, pathname, flags, &nd); if (unlikely(error)) - goto out_filp; + goto out_filp2; error = -ELOOP; if (!(nd.flags & LOOKUP_FOLLOW)) { if (nd.inode->i_op->follow_link) - goto out_path; + goto out_path2; } error = -ENOTDIR; if (nd.flags & LOOKUP_DIRECTORY) { if (!nd.inode->i_op->lookup) - goto out_path; + goto out_path2; } audit_inode(pathname, nd.path.dentry); filp = finish_open(&nd, open_flag, acc_mode); +out2: release_open_intent(&nd); return filp; +out_path2: + path_put(&nd.path); +out_filp2: + filp = ERR_PTR(error); + goto out2; + creat: /* OK, have to create the file. Find the parent. */ error = path_init_rcu(dfd, pathname, |