On Wed, Jun 02, 2021 at 09:37:26AM -0700, syzbot wrote: > Hello, > > syzbot found the following issue on: > > HEAD commit: 6850ec97 Merge branch 'mptcp-fixes-for-5-13' > git tree: net > console output: https://syzkaller.appspot.com/x/log.txt?x=1355504dd00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=770708ea7cfd4916 > dashboard link: https://syzkaller.appspot.com/bug?extid=ce96ca2b1d0b37c6422d > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1502d517d00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12bbbe13d00000 > > The issue was bisected to: > > commit 05abe4456fa376040f6cc3cc6830d2e328723478 > Author: Pablo Neira Ayuso <pablo@xxxxxxxxxxxxx> > Date: Wed May 20 13:44:37 2020 +0000 > > netfilter: nf_tables: allow to register flowtable with no devices > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=10fa1387d00000 > final oops: https://syzkaller.appspot.com/x/report.txt?x=12fa1387d00000 > console output: https://syzkaller.appspot.com/x/log.txt?x=14fa1387d00000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+ce96ca2b1d0b37c6422d@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: 05abe4456fa3 ("netfilter: nf_tables: allow to register flowtable with no devices") > > general protection fault, probably for non-canonical address 0xdffffc000000000e: 0000 [#1] PREEMPT SMP KASAN > KASAN: null-ptr-deref in range [0x0000000000000070-0x0000000000000077] > CPU: 1 PID: 8438 Comm: syz-executor343 Not tainted 5.13.0-rc3-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:nft_set_elem_expr_alloc+0x17e/0x280 net/netfilter/nf_tables_api.c:5321 > Code: 48 c1 ea 03 80 3c 02 00 0f 85 09 01 00 00 49 8b 9d c0 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 70 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 d9 00 00 00 48 8b 5b 70 48 85 db 74 21 e8 9a bd It's a real bug. Bisect is not correct though. I'll post a patch to fix it. Thanks.