JIRA: https://issues.redhat.com/browse/RHEL-79456



commit 341468e0ab4bb1b26ad0b0cee7c6db4bf283043a
Author: Ming Lei <ming.lei@redhat.com>
Date:   Sat Nov 2 09:42:11 2024 +0800

    lib/iov_iter: fix bvec iterator setup

    .bi_size of bvec iterator should be initialized as real max size for
    walking, and .bi_bvec_done just counts how many bytes need to be
    skipped in the 1st bvec, so .bi_size isn't related with .bi_bvec_done.

    This patch fixes bvec iterator initialization, and the inner `size`
    check isn't needed any more, so revert Eric Dumazet's commit
    7bc802acf193 ("iov-iter: do not return more bytes than requested in
    iov_iter_extract_bvec_pages()").

    Cc: Eric Dumazet <edumazet@google.com>
    Fixes: e4e535bff2bc ("iov_iter: don't require contiguous pages in iov_iter_extract_bvec_pages")
Reported-by:  <syzbot+71abe7ab2b70bca770fd@syzkaller.appspotmail.com>
Tested-by:  <syzbot+71abe7ab2b70bca770fd@syzkaller.appspotmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Signed-off-by: Ming Lei <ming.lei@redhat.com>