lkml.org 
[lkml]   [2003]   [Jan]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [CHECKER] 87 potential array bounds error/buffer overruns in 2.5.53
    From
    Date
    On Sun, 2003-01-26 at 19:35, Yichen Xie wrote:
    > Hi all,
    >
    > Attached are 87 potential buffer overruns in 2.5.53. Most arise from
    > improper bounds checks, and some might be security holes where the array
    > index comes from an untrusted source (e.g. copy_from_user). In the bug
    > report, "len" refers to the length of the array or buffer being
    > accessed, and "off" refers to the offset/index that is being used to
    > access it. (off >= len) corresponds to a buffer overrun, while (off < 0)
    > signals an underrun.
    >
    > As always, confirmations and comments will be appreciated.
    >
    > Yichen
    >

    > [BUG] what if level < 0?
    > /home/yxie/linux-2.5.53/fs/xfs/xfs_bmap_btree.c:1364:xfs_bmbt_lshift:
    > ERROR:BUFFER:1364:1364:Array bounds error (off < 0)
    > ((*cur).bc_ptrs[level], max(off) = -1)
    > }
    > if ((error = xfs_bmbt_updkey(cur, rkp, level + 1))) {
    > XFS_BMBT_TRACE_CURSOR(cur, ERROR);
    > return error;
    > }
    >
    > Error --->
    > cur->bc_ptrs[level]--;
    > XFS_BMBT_TRACE_CURSOR(cur, EXIT);
    > *stat = 1;
    > return 0;

    Hi,

    I took a look at the callers of this code, level is always being passed
    in as 0 or greater. Looking at it, we should really be using an unsigned
    int for this variable.

    Interesting that this is the only one in the file which showed up, there
    are lots of array dereferences using level as the index in this file.

    Steve


    -
    To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
    the body of a message to majordomo@vger.kernel.org
    More majordomo info at http://vger.kernel.org/majordomo-info.html
    Please read the FAQ at http://www.tux.org/lkml/

    \
     
     \ /
      Last update: 2005-03-22 13:32    [W:0.022 / U:60.144 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site