Martin KaFai Lau <martin.lau@xxxxxxxxx> writes: > On 7/15/24 11:13 AM, Michal Switala wrote: > > >> Reported-by: syzbot+cca39e6e84a367a7e6f6@xxxxxxxxxxxxxxxxxxxxxxxxx > >> Closes: https://syzkaller.appspot.com/bug?extid=cca39e6e84a367a7e6f6 > >> Link: https://lore.kernel.org/all/000000000000b95d41061cbf302a@xxxxxxxxxx/ > > > > Something doesn't add up. > > This syzbot report is about: > > > > dev_map_enqueue+0x31/0x3e0 kernel/bpf/devmap.c:539 > > __xdp_do_redirect_frame net/core/filter.c:4397 [inline] > > bpf_prog_test_run_xdp > > > > why you're fixing bpf_prog_test_run_skb ? > > > [ Please keep the relevant email context in the reply ] > > >> The reproducer calls the methods bpf_prog_test_run_xdp and >> bpf_prog_test_run_skb. Both lead to the invocation of dev_map_enqueue, in the > > The syzbot report is triggering from the bpf_prog_test_run_xdp. I agree with > Alexei that fixing the bpf_prog_test_run_skb does not make sense. At least I > don't see how dev_map_enqueue can be used from bpf_prog_test_run_skb. Me neither. > It looks very similar to > https://lore.kernel.org/bpf/000000000000f6531b061494e696@xxxxxxxxxx/. It has > been fixed in commit 5bcf0dcbf906 ("xdp: use flags field to disambiguate > broadcast redirect") > > I tried the C repro. I can reproduce in the bpf tree also which should have the > fix. I cannot reproduce in the bpf-next though. > > Cc Toke who knows more details here. Hmm, yeah, it does look kinda similar. Do you mean that the C repro from this new report triggers the crash for you on the current -bpf tree? -Toke
