bisecting fixing commit since 6f513529296fd4f696afb4354c46508abe646541 building syzkaller on 49ca1f59e37fcf63dc38a6bd2b60fcc47a0a708e testing commit 6f513529296fd4f696afb4354c46508abe646541 compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: a53ad9d52b393896d2f0b6b838be9a7d0ed08da33fc7fd1c1d8a0e6c1a0c55f7 all runs: crashed: general protection fault in skb_clone testing current HEAD 8d0749b4f83bf4768ceae45ee6a79e6e7eddfc2a testing commit 8d0749b4f83bf4768ceae45ee6a79e6e7eddfc2a compiler: gcc (GCC) 10.2.1 20210217, GNU ld (GNU Binutils for Debian) 2.35.2 kernel signature: b8bf3512990cbbcf042055388a7f1478c45c11b054ec57e1e1ddb57592f3b0da all runs: crashed: general protection fault in skb_clone revisions tested: 2, total time: 20m11.211307156s (build: 12m42.092350524s, test: 6m45.787982971s) the crash still happens on HEAD commit msg: Merge tag 'drm-next-2022-01-07' of git://anongit.freedesktop.org/drm/drm crash: general protection fault in skb_clone Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 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 cc fd ff ff 48 RSP: 002b:00007f818fe312c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f818ff0c4e0 RCX: 00007f818fe441ff RDX: 000000000000000e RSI: 0000000020000100 RDI: 00000000000000c8 RBP: 00007f818fed96cc R08: 0000000000000000 R09: 0000000000000001 R10: 00007f818fe31087 R11: 0000000000000293 R12: 00007f818ff0c4ec R13: 00007f818fe312f0 R14: 00007f818ff0c4e8 R15: 0000000000000001 general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] CPU: 0 PID: 4254 Comm: syz-executor620 Not tainted 5.16.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:skb_clone+0xdf/0x300 net/core/skbuff.c:1513 Code: 02 00 0f 85 fd 01 00 00 48 8b 5b 28 48 85 db 0f 85 ab 00 00 00 4c 8d 75 7e 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <0f> b6 04 02 4c 89 f2 83 e2 07 38 d0 7f 08 84 c0 0f 85 44 01 00 00 RSP: 0018:ffffc900027cf598 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffff888020c87700 RCX: 1ffff11003a350b8 RDX: 000000000000000f RSI: 0000000000000a20 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000140 R09: ffffffff8acbe673 R10: fffffbfff1597cce R11: 0000000000000001 R12: 0000000000000a20 R13: dffffc0000000000 R14: 000000000000007e R15: ffffc900027cf638 FS: 00007f818fe31700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f818fef1364 CR3: 00000000180a6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: hsr_forward_do net/hsr/hsr_forward.c:461 [inline] hsr_forward_skb+0x9fb/0x18b0 net/hsr/hsr_forward.c:620 hsr_handle_frame+0x47b/0x680 net/hsr/hsr_slave.c:69 __netif_receive_skb_core+0x779/0x2de0 net/core/dev.c:5359 __netif_receive_skb_one_core+0xaa/0x180 net/core/dev.c:5463 netif_receive_skb_internal net/core/dev.c:5665 [inline] netif_receive_skb+0xec/0x640 net/core/dev.c:5724 tun_rx_batched.isra.0+0x4b5/0x7d0 drivers/net/tun.c:1516 tun_get_user+0x1c76/0x2e00 drivers/net/tun.c:1963 tun_chr_write_iter+0xb9/0x160 drivers/net/tun.c:1993 call_write_iter include/linux/fs.h:2162 [inline] new_sync_write+0x360/0x600 fs/read_write.c:503 vfs_write+0x609/0x900 fs/read_write.c:590 ksys_write+0xf4/0x1d0 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f818fe441ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 99 fd ff ff 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 cc fd ff ff 48 RSP: 002b:00007f818fe312c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f818ff0c4e0 RCX: 00007f818fe441ff RDX: 000000000000000e RSI: 0000000020000100 RDI: 00000000000000c8 RBP: 00007f818fed96cc R08: 0000000000000000 R09: 0000000000000001 R10: 00007f818fe31087 R11: 0000000000000293 R12: 00007f818ff0c4ec R13: 00007f818fe312f0 R14: 00007f818ff0c4e8 R15: 0000000000000001 Modules linked in: ---[ end trace 0f737534ab3545c9 ]--- RIP: 0010:skb_clone+0xdf/0x300 net/core/skbuff.c:1513 Code: 02 00 0f 85 fd 01 00 00 48 8b 5b 28 48 85 db 0f 85 ab 00 00 00 4c 8d 75 7e 48 b8 00 00 00 00 00 fc ff df 4c 89 f2 48 c1 ea 03 <0f> b6 04 02 4c 89 f2 83 e2 07 38 d0 7f 08 84 c0 0f 85 44 01 00 00 RSP: 0018:ffffc900027cf598 EFLAGS: 00010207 RAX: dffffc0000000000 RBX: ffff888020c87700 RCX: 1ffff11003a350b8 RDX: 000000000000000f RSI: 0000000000000a20 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000140 R09: ffffffff8acbe673 R10: fffffbfff1597cce R11: 0000000000000001 R12: 0000000000000a20 R13: dffffc0000000000 R14: 000000000000007e R15: ffffc900027cf638 FS: 00007f818fe31700(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f818fef1364 CR3: 00000000180a6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 89 54 24 18 mov %edx,0x18(%rsp) 4: 48 89 74 24 10 mov %rsi,0x10(%rsp) 9: 89 7c 24 08 mov %edi,0x8(%rsp) d: e8 99 fd ff ff callq 0xfffffdab 12: 48 8b 54 24 18 mov 0x18(%rsp),%rdx 17: 48 8b 74 24 10 mov 0x10(%rsp),%rsi 1c: 41 89 c0 mov %eax,%r8d 1f: 8b 7c 24 08 mov 0x8(%rsp),%edi 23: b8 01 00 00 00 mov $0x1,%eax 28: 0f 05 syscall * 2a: 48 3d 00 f0 ff ff cmp $0xfffffffffffff000,%rax <-- trapping instruction 30: 77 31 ja 0x63 32: 44 89 c7 mov %r8d,%edi 35: 48 89 44 24 08 mov %rax,0x8(%rsp) 3a: e8 cc fd ff ff callq 0xfffffe0b 3f: 48 rex.W