----- Original Message -----
> The cifs code will attempt to open files on lookup under certain
> circumstances. What happens though if we find that the file we opened
> was actually a FIFO or other special file?
> 
> Currently, the open filehandle just ends up being leaked leading to
> a dentry refcount mismatch and oops on umount. Fix this by having the
> code close the filehandle on the server if it turns out not to be a
> regular file. While we're at it, change this spaghetti if statement
> into a switch too.
> 
> Cc: [email protected]
> Reported-by: CAI Qian <[email protected]>
> Signed-off-by: Jeff Layton <[email protected]>
Tested-by: CAI Qian <[email protected]>
> ---
>  fs/cifs/dir.c |   20 ++++++++++++++++++--
>  1 files changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
> index 63a196b..bc7e244 100644
> --- a/fs/cifs/dir.c
> +++ b/fs/cifs/dir.c
> @@ -584,10 +584,26 @@ cifs_lookup(struct inode *parent_dir_inode,
> struct dentry *direntry,
>                        * If either that or op not supported returned, follow
>                        * the normal lookup.
>                        */
> -                     if ((rc == 0) || (rc == -ENOENT))
> +                     switch (rc) {
> +                     case 0:
> +                             /*
> +                              * The server may allow us to open things like
> +                              * FIFOs, but the client isn't set up to deal
> +                              * with that. If it's not a regular file, just
> +                              * close it and proceed as if it were a normal
> +                              * lookup.
> +                              */
> +                             if (newInode && !S_ISREG(newInode->i_mode)) {
> +                                     CIFSSMBClose(xid, pTcon, fileHandle);
> +                                     break;
> +                             }
> +                     case -ENOENT:
>                               posix_open = true;
> -                     else if ((rc == -EINVAL) || (rc != -EOPNOTSUPP))
> +                     case -EOPNOTSUPP:
> +                             break;
> +                     default:
>                               pTcon->broken_posix_open = true;
> +                     }
>               }
>               if (!posix_open)
>                       rc = cifs_get_inode_info_unix(&newInode, full_path,
> --
> 1.7.7.6
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-cifs"
> in
> the body of a message to [email protected]
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-cifs" in
the body of a message to [email protected]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to