• Ritesh Harjani's avatar
    fibmap: Warn and return an error in case of block > INT_MAX · b75dfde1
    Ritesh Harjani authored
    We better warn the fibmap user and not return a truncated and therefore
    an incorrect block map address if the bmap() returned block address
    is greater than INT_MAX (since user supplied integer pointer).
    
    It's better to pr_warn() all user of ioctl_fibmap() and return a proper
    error code rather than silently letting a FS corruption happen if the
    user tries to fiddle around with the returned block map address.
    
    We fix this by returning an error code of -ERANGE and returning 0 as the
    block mapping address in case if it is > INT_MAX.
    
    Now iomap_bmap() could be called from either of these two paths.
    Either when a user is calling an ioctl_fibmap() interface to get
    the block mapping address or by some filesystem via use of bmap()
    internal kernel API.
    bmap() kernel API is well equipped with handling of u64 addresses.
    
    WARN condition in iomap_bmap_actor() was mainly added to warn all
    the fibmap users. But now that we have directly added this warning
    for all fibmap users and also made sure to return 0 as block map address
    in case if addr > INT_MAX.
    So we can now remove this logic from iomap_bmap_actor().
    Signed-off-by: default avatarRitesh Harjani <riteshh@linux.ibm.com>
    Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
    Reviewed-by: default avatarJan Kara <jack@suse.cz>
    Reviewed-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    Signed-off-by: default avatarDarrick J. Wong <darrick.wong@oracle.com>
    b75dfde1
ioctl.c 21.5 KB