| Message ID | 20210222191222.4093800-7-viro@zeniv.linux.org.uk (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [1/8] af_unix: take address assignment/hash insertion into a new helper | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | warning | Series does not have a cover letter |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Guessed tree name to be net-next |
| netdev/subject_prefix | warning | Target tree name not specified in the subject |
| netdev/cc_maintainers | warning | 5 maintainers not CCed: davem@davemloft.net pabeni@redhat.com jingxiangfeng@huawei.com ktkhai@virtuozzo.com orcohen2006@gmail.com |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 4 this patch: 4 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 49 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 4 this patch: 4 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c index 368376621111..8bbdcddbf598 100644 --- a/net/unix/af_unix.c +++ b/net/unix/af_unix.c @@ -1000,27 +1000,19 @@ static int unix_bind_bsd(struct sock *sk, struct unix_address *addr) dentry = kern_path_create(AT_FDCWD, addr->name->sun_path, &parent, 0); if (IS_ERR(dentry)) return PTR_ERR(dentry); - /* * All right, let's create it. */ err = security_path_mknod(&parent, dentry, mode, 0); if (!err) err = vfs_mknod(d_inode(parent.dentry), dentry, mode, 0); - if (err) { - done_path_create(&parent, dentry); - return err; - } + if (err) + goto out; err = mutex_lock_interruptible(&u->bindlock); - if (err) { - done_path_create(&parent, dentry); - return err; - } - if (u->addr) { - mutex_unlock(&u->bindlock); - done_path_create(&parent, dentry); - return -EINVAL; - } + if (err) + goto out_unlink; + if (u->addr) + goto out_unlock; addr->hash = UNIX_HASH_SIZE; hash = d_backing_inode(dentry)->i_ino & (UNIX_HASH_SIZE - 1); @@ -1032,6 +1024,16 @@ static int unix_bind_bsd(struct sock *sk, struct unix_address *addr) mutex_unlock(&u->bindlock); done_path_create(&parent, dentry); return 0; + +out_unlock: + mutex_unlock(&u->bindlock); + err = -EINVAL; +out_unlink: + /* failed after successful mknod? unlink what we'd created... */ + vfs_unlink(d_inode(parent.dentry), dentry, NULL); +out: + done_path_create(&parent, dentry); + return err; } static int unix_bind_abstract(struct sock *sk, unsigned hash,
We can do that more or less safely, since the parent is held locked all along. Yes, somebody might observe the object via dcache, only to have it disappear afterwards, but there's really no good way to prevent that. It won't race with other bind(2) or attempts to move the sucker elsewhere, or put something else in its place - locked parent prevents that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- net/unix/af_unix.c | 30 ++++++++++++++++-------------- 1 file changed, 16 insertions(+), 14 deletions(-)