syzbot has found a reproducer for the following issue on: HEAD commit: 1c5fc27bc48a Merge tag 'nf-next-24-06-28' of git://git.ker.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=14aeab3e980000 kernel config: https://syzkaller.appspot.com/x/.config?x=5264b58fdff6e881 dashboard link: https://syzkaller.appspot.com/bug?extid=5ae46b237278e2369cac compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1673738e980000 Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/9672225af907/disk-1c5fc27b.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/0f14d163a914/vmlinux-1c5fc27b.xz kernel image: https://storage.googleapis.com/syzbot-assets/ec6c331e6a6e/bzImage-1c5fc27b.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+5ae46b237278e2369cac@xxxxxxxxxxxxxxxxxxxxxxxxx Oops: stack segment: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 PID: 14042 Comm: syz.0.2930 Not tainted 6.10.0-rc5-syzkaller-01137-g1c5fc27bc48a #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:bpf_net_ctx_get_ri include/linux/filter.h:788 [inline] RIP: 0010:____bpf_xdp_redirect net/core/filter.c:4544 [inline] RIP: 0010:bpf_xdp_redirect+0x59/0x1a0 net/core/filter.c:4542 Code: 81 c3 08 18 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 55 1a 99 f8 48 8b 1b 4c 8d 63 38 4c 89 e5 48 c1 ed 03 <42> 0f b6 44 2d 00 84 c0 0f 85 d0 00 00 00 45 8b 34 24 44 89 f6 83 RSP: 0018:ffffc9000aaf7970 EFLAGS: 00010202 RAX: 1ffff1100536be41 RBX: 0000000000000000 RCX: ffff888029b5da00 RDX: 0000000000000000 RSI: 000000000000a020 RDI: ffffc9000aaf7af0 RBP: 0000000000000007 R08: ffffffff8665e84f R09: 1ffffffff25f78b0 R10: dffffc0000000000 R11: fffffbfff25f78b1 R12: 0000000000000038 R13: dffffc0000000000 R14: ffffc90009f63048 R15: 000000000000a020 FS: 00007f2c699ff6c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa0bea356dd CR3: 000000007a9bc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> bpf_prog_bc55b47b7a2429cd+0x1d/0x1f __bpf_prog_run include/linux/filter.h:691 [inline] bpf_prog_run_xdp include/net/xdp.h:514 [inline] tun_build_skb drivers/net/tun.c:1711 [inline] tun_get_user+0x3321/0x4560 drivers/net/tun.c:1819 tun_chr_write_iter+0x113/0x1f0 drivers/net/tun.c:2048 new_sync_write fs/read_write.c:497 [inline] vfs_write+0xa72/0xc90 fs/read_write.c:590 ksys_write+0x1a0/0x2c0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2c69f7471f Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 29 8c 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 7c 8c 02 00 48 RSP: 002b:00007f2c699ff010 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f2c6a103fa0 RCX: 00007f2c69f7471f RDX: 0000000000000032 RSI: 0000000020001500 RDI: 00000000000000c8 RBP: 00007f2c69ff677e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000032 R11: 0000000000000293 R12: 0000000000000000 R13: 000000000000000b R14: 00007f2c6a103fa0 R15: 00007ffd4d9d6998 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:bpf_net_ctx_get_ri include/linux/filter.h:788 [inline] RIP: 0010:____bpf_xdp_redirect net/core/filter.c:4544 [inline] RIP: 0010:bpf_xdp_redirect+0x59/0x1a0 net/core/filter.c:4542 Code: 81 c3 08 18 00 00 48 89 d8 48 c1 e8 03 42 80 3c 28 00 74 08 48 89 df e8 55 1a 99 f8 48 8b 1b 4c 8d 63 38 4c 89 e5 48 c1 ed 03 <42> 0f b6 44 2d 00 84 c0 0f 85 d0 00 00 00 45 8b 34 24 44 89 f6 83 RSP: 0018:ffffc9000aaf7970 EFLAGS: 00010202 RAX: 1ffff1100536be41 RBX: 0000000000000000 RCX: ffff888029b5da00 RDX: 0000000000000000 RSI: 000000000000a020 RDI: ffffc9000aaf7af0 RBP: 0000000000000007 R08: ffffffff8665e84f R09: 1ffffffff25f78b0 R10: dffffc0000000000 R11: fffffbfff25f78b1 R12: 0000000000000038 R13: dffffc0000000000 R14: ffffc90009f63048 R15: 000000000000a020 FS: 00007f2c699ff6c0(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa0bea356dd CR3: 000000007a9bc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 81 c3 08 18 00 00 add $0x1808,%ebx 6: 48 89 d8 mov %rbx,%rax 9: 48 c1 e8 03 shr $0x3,%rax d: 42 80 3c 28 00 cmpb $0x0,(%rax,%r13,1) 12: 74 08 je 0x1c 14: 48 89 df mov %rbx,%rdi 17: e8 55 1a 99 f8 call 0xf8991a71 1c: 48 8b 1b mov (%rbx),%rbx 1f: 4c 8d 63 38 lea 0x38(%rbx),%r12 23: 4c 89 e5 mov %r12,%rbp 26: 48 c1 ed 03 shr $0x3,%rbp * 2a: 42 0f b6 44 2d 00 movzbl 0x0(%rbp,%r13,1),%eax <-- trapping instruction 30: 84 c0 test %al,%al 32: 0f 85 d0 00 00 00 jne 0x108 38: 45 8b 34 24 mov (%r12),%r14d 3c: 44 89 f6 mov %r14d,%esi 3f: 83 .byte 0x83 --- 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.
