Messages in this thread | | | Subject | Re: [PATCH] bpf: fix kmalloc bug in bpf_check | From | Yonghong Song <> | Date | Mon, 13 Sep 2021 08:33:51 -0700 |
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On 9/13/21 4:02 AM, Dongliang Mu wrote: > Since 7661809d493b ("mm: don't allow oversized kvmalloc() calls > ") does not allow oversized kvmalloc, it triggers a kmalloc bug warning > at bpf_check. > > Fix it by adding a sanity check in th check_btf_line. > > Reported-by: syzbot+f3e749d4c662818ae439@syzkaller.appspotmail.com > Fixes: 7661809d493b ("mm: don't allow oversized kvmalloc() calls") > Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Thanks for the fix. A similar patch has been proposed here: https://lore.kernel.org/bpf/20210911005557.45518-1-cuibixuan@huawei.com/
> --- > kernel/bpf/verifier.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c > index 047ac4b4703b..3c5a79f78bc5 100644 > --- a/kernel/bpf/verifier.c > +++ b/kernel/bpf/verifier.c > @@ -9913,6 +9913,9 @@ static int check_btf_line(struct bpf_verifier_env *env, > if (!nr_linfo) > return 0; > > + if (nr_linfo > INT_MAX/sizeof(struct bpf_line_info)) > + return -EINVAL; > + > rec_size = attr->line_info_rec_size; > if (rec_size < MIN_BPF_LINEINFO_SIZE || > rec_size > MAX_LINEINFO_REC_SIZE || >
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