Re: [PATCH V4] ocfs2: pass u64 to ocfs2_truncate_inline maybe overflow
From: Joseph Qi
Date: Wed Oct 16 2024 - 07:47:34 EST
On 10/16/24 7:43 PM, Edward Adam Davis wrote:
> Syzbot reported a kernel BUG in ocfs2_truncate_inline.
> There are two reasons for this: first, the parameter value passed is greater
> than ocfs2_max_inline_data_with_xattr, second, the start and end parameters
> of ocfs2_truncate_inline are "unsigned int".
>
> So, we need to add a sanity check for byte_start and byte_len right before
> ocfs2_truncate_inline() in ocfs2_remove_inode_range(), if they are greater
> than ocfs2_max_inline_data_with_xattr return -EINVAL.
>
> Reported-by: syzbot+81092778aac03460d6b7@xxxxxxxxxxxxxxxxxxxxxxxxx
> Closes: https://syzkaller.appspot.com/bug?extid=81092778aac03460d6b7
> Signed-off-by: Edward Adam Davis <eadavis@xxxxxx>
Looks fine.
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxxxxxxxxx>
> ---
> V1 -> V2: move sanity check to ocfs2_remove_inode_range
> V2 -> V3: use ocfs2_max_inline_data_with_xattr return value replace UINT_MAX
> V3 -> V4: rename variable, modify return value and comments
>
> fs/ocfs2/file.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
> index ad131a2fc58e..47121ee4b4df 100644
> --- a/fs/ocfs2/file.c
> +++ b/fs/ocfs2/file.c
> @@ -1784,6 +1784,14 @@ int ocfs2_remove_inode_range(struct inode *inode,
> return 0;
>
> if (OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) {
> + int id_count = ocfs2_max_inline_data_with_xattr(inode->i_sb, di);
> +
> + if (byte_start > id_count || byte_start + byte_len > id_count) {
> + ret = -EINVAL;
> + mlog_errno(ret);
> + goto out;
> + }
> +
> ret = ocfs2_truncate_inline(inode, di_bh, byte_start,
> byte_start + byte_len, 0);
> if (ret) {