Hello, syzbot found the following issue on: HEAD commit: 155a3c003e55 Merge tag 'for-6.16/dm-fixes-2' of git://git... git tree: upstream console+strace: https://syzkaller.appspot.com/x/log.txt?x=161a27d4580000 kernel config: https://syzkaller.appspot.com/x/.config?x=5ae63460f9c371aa dashboard link: https://syzkaller.appspot.com/bug?extid=92c5daf9a23f04ccfc99 compiler: gcc (Debian 12.2.0-14+deb12u1) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15a9d18c580000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13f58382580000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/dcbbac96d733/disk-155a3c00.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/eec589968921/vmlinux-155a3c00.xz kernel image: https://storage.googleapis.com/syzbot-assets/80e95076a622/bzImage-155a3c00.xz The issue was bisected to: commit 91721c2d02d3a0141df8a4787c7079b89b0d0607 Author: Daniel Xu <dxu@xxxxxxxxx> Date: Fri Jul 21 20:22:46 2023 +0000 netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=12c1558c580000 final oops: https://syzkaller.appspot.com/x/report.txt?x=11c1558c580000 console output: https://syzkaller.appspot.com/x/log.txt?x=16c1558c580000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+92c5daf9a23f04ccfc99@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 91721c2d02d3 ("netfilter: bpf: Support BPF_F_NETFILTER_IP_DEFRAG in netfilter link") BUG: assuming non migratable context at ./include/linux/filter.h:703 in_atomic(): 0, irqs_disabled(): 0, migration_disabled() 0 pid: 5829, name: sshd-session 3 locks held by sshd-session/5829: #0: ffff88807b4e4218 (sk_lock-AF_INET){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline] #0: ffff88807b4e4218 (sk_lock-AF_INET){+.+.}-{0:0}, at: tcp_sendmsg+0x20/0x50 net/ipv4/tcp.c:1395 #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #1: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: __ip_queue_xmit+0x69/0x26c0 net/ipv4/ip_output.c:470 #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock include/linux/rcupdate.h:841 [inline] #2: ffffffff8e5c4e00 (rcu_read_lock){....}-{1:3}, at: nf_hook+0xb2/0x680 include/linux/netfilter.h:241 CPU: 0 UID: 0 PID: 5829 Comm: sshd-session Not tainted 6.16.0-rc6-syzkaller-00002-g155a3c003e55 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x16c/0x1f0 lib/dump_stack.c:120 __cant_migrate kernel/sched/core.c:8860 [inline] __cant_migrate+0x1c7/0x250 kernel/sched/core.c:8834 __bpf_prog_run include/linux/filter.h:703 [inline] bpf_prog_run include/linux/filter.h:725 [inline] nf_hook_run_bpf+0x83/0x1e0 net/netfilter/nf_bpf_link.c:20 nf_hook_entry_hookfn include/linux/netfilter.h:157 [inline] nf_hook_slow+0xbb/0x200 net/netfilter/core.c:623 nf_hook+0x370/0x680 include/linux/netfilter.h:272 NF_HOOK_COND include/linux/netfilter.h:305 [inline] ip_output+0x1bc/0x2a0 net/ipv4/ip_output.c:433 dst_output include/net/dst.h:459 [inline] ip_local_out net/ipv4/ip_output.c:129 [inline] __ip_queue_xmit+0x1d7d/0x26c0 net/ipv4/ip_output.c:527 __tcp_transmit_skb+0x2686/0x3e90 net/ipv4/tcp_output.c:1479 tcp_transmit_skb net/ipv4/tcp_output.c:1497 [inline] tcp_write_xmit+0x1274/0x84e0 net/ipv4/tcp_output.c:2838 __tcp_push_pending_frames+0xaf/0x390 net/ipv4/tcp_output.c:3021 tcp_push+0x225/0x700 net/ipv4/tcp.c:759 tcp_sendmsg_locked+0x1870/0x42b0 net/ipv4/tcp.c:1359 tcp_sendmsg+0x2e/0x50 net/ipv4/tcp.c:1396 inet_sendmsg+0xb9/0x140 net/ipv4/af_inet.c:851 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg net/socket.c:727 [inline] sock_write_iter+0x4aa/0x5b0 net/socket.c:1131 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x6c7/0x1150 fs/read_write.c:686 ksys_write+0x1f8/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fe7d365d407 Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff RSP: --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. For information about bisection process see: https://goo.gl/tpsmEJ#bisection If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want syzbot to run the reproducer, reply with: #syz test: git://repo/address.git branch-or-commit-hash If you attach or paste a git patch, syzbot will apply it before testing. If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup