Re: [reiserfs-list] major security bug in reiserfs (may affect SuSE Linux)

["Vladimir V. Saveliev" <vs@namesys.botik.ru>]

Hi

Chris Mason wrote:

> On Wednesday, January 10, 2001 02:32:09 AM +0100 Marc Lehmann <pcg@goof.com> wrote:
>
> >>> EIP; c013f911 <filldir+20b/221>   <=====
> > Trace; c013f706 <filldir+0/221>
> > Trace; c0136e01 <reiserfs_getblk+2a/16d>
>
> The buffer reiserfs is sending to filldir is big enough for
> the huge file name, so I think the real fix should be done in VFSland.
>
> But, in the interest of providing a quick, obviously correct fix, this
> reiserfs only patch will refuse to create file names larger
> than 255 chars, and skip over any directory entries larger than
> 255 chars.
>

Hmm, wouldn't it make existing long named files unreachable?

Thanks,
vs




>
> --- linux/include/linux/reiserfs_fs.h.1 Tue Jan  9 21:56:18 2001
> +++ linux/include/linux/reiserfs_fs.h   Tue Jan  9 21:56:33 2001
> @@ -467,7 +467,7 @@
>  /* name by bh, ih and entry_num */
>  #define B_I_E_NAME(entry_num,bh,ih) ((char *)(bh->b_data + ih->ih_item_location + (B_I_DEH(bh,ih)+(entry_num))->deh_location))
>
> -#define REISERFS_MAX_NAME_LEN(block_size) (block_size - BLKH_SIZE - IH_SIZE - DEH_SIZE)        /* -SD_SIZE when entry will contain stat data */
> +#define REISERFS_MAX_NAME_LEN(block_size) 255
>
>  /* this structure is used for operations on directory entries. It is not a disk structure. */
>  /* When reiserfs_find_entry or search_by_entry_key find directory entry, they return filled reiserfs_dir_entry structure */
> --- linux/fs/reiserfs/dir.c.1   Tue Jan  9 22:06:06 2001
> +++ linux/fs/reiserfs/dir.c     Tue Jan  9 22:15:17 2001
> @@ -159,6 +159,10 @@
>                 d_name = B_I_DEH_ENTRY_FILE_NAME (bh, ih, deh);
>                 d_off = deh->deh_offset;
>                 d_ino = deh->deh_objectid;
> +               if (d_reclen > REISERFS_MAX_NAME_LEN(inode->i_sb->s_blocksize)){
> +                   /* it is too big to send back to VFS */
> +                   continue ;
> +               }
>                 if (d_reclen <= 32) {
>                     local_buf = small_buf ;
>                 } else {

-
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