• NeilBrown's avatar
    [PATCH] knfsd: fix an NFSD bug with full sized, non-page-aligned reads · 250f3915
    NeilBrown authored
    NFSd assumes that largest number of pages that will be needed for a
    request+response is 2+N where N pages is the size of the largest permitted
    read/write request.  The '2' are 1 for the non-data part of the request, and 1
    for the non-data part of the reply.
    
    However, when a read request is not page-aligned, and we choose to use
    ->sendfile to send it directly from the page cache, we may need N+1 pages to
    hold the whole reply.  This can overflow and array and cause an Oops.
    
    This patch increases size of the array for holding pages by one and makes sure
    that entry is NULL when it is not in use.
    Signed-off-by: default avatarNeil Brown <neilb@suse.de>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
    250f3915
vfs.c 46.9 KB