bisecting fixing commit since c3d8f220d01220a5b253e422be407d068dc65511
building syzkaller on 1da71ab086c5d9e6a32beae37b109efaa856b257
testing commit c3d8f220d01220a5b253e422be407d068dc65511 with gcc (GCC) 8.1.0
kernel signature: 05c8d7830c28fca934ca90691a45490109eba3fdc7cbbaab6bbdc032ae63ada5
run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #1: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
testing current HEAD 865c50e1d279671728c2936cb7680eb89355eeea
testing commit 865c50e1d279671728c2936cb7680eb89355eeea with gcc (GCC) 8.1.0
kernel signature: 0285bb6095b8f93ce99a90a0c055f7afb6f2b589d2d825a29d9d97ba2130a983
run #0: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #1: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #2: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #3: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #4: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #5: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #6: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #7: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #8: crashed: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
run #9: OK
revisions tested: 2, total time: 28m49.829800723s (build: 9m13.871382466s, test: 19m11.782694462s)
the crash still happens on HEAD
commit msg: x86/uaccess: utilize CONFIG_CC_HAS_ASM_GOTO_OUTPUT
crash: BUG: unable to handle kernel NULL pointer dereference in bpf_prog_ADDR
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 10f385067 P4D 10f385067 PUD 10c1bc067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP
CPU: 1 PID: 20750 Comm: syz-executor.1 Not tainted 5.9.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:bpf_prog_cd248b930ddf8412+0x1f/0x824
Code: cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 55 48 89 e5 48 81 ec 00 00 00 00 53 41 55 41 56 41 57 6a 00 31 c0 48 8b 47 28 <48> 8b 40 00 8b 80 00 01 00 00 5b 41 5f 41 5e 41 5d 5b c9 c3 cc cc
RSP: 0018:ffffc90000f0fce8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000018
RDX: ffffffffa006c7dc RSI: ffffc90000ea5038 RDI: ffffc90000f0fde0
RBP: ffffc90000f0fd10 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: ffff88810dbda100 R12: 0000000000029910
R13: 0000000000000001 R14: ffffc90000f0fdd8 R15: 0000000000000001
FS:  00007f7d2e3f3700(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000010c159000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 bpf_prog_run_xdp include/linux/filter.h:734 [inline]
 bpf_test_run+0x12c/0x4d0 net/bpf/test_run.c:47
 bpf_prog_test_run_xdp+0x126/0x1a0 net/bpf/test_run.c:563
 bpf_prog_test_run kernel/bpf/syscall.c:2996 [inline]
 __do_sys_bpf+0x893/0x1c90 kernel/bpf/syscall.c:4196
 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45d4d9
Code: 5d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7d2e3f2c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 0000000000001440 RCX: 000000000045d4d9
RDX: 0000000000000010 RSI: 0000000020001300 RDI: 000000000000000a
RBP: 000000000118d020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118cfec
R13: 00007fffdc76814f R14: 00007f7d2e3f39c0 R15: 000000000118cfec
Modules linked in:
CR2: 0000000000000000
---[ end trace 6b36f72b985f0949 ]---
RIP: 0010:bpf_prog_cd248b930ddf8412+0x1f/0x824
Code: cc cc cc cc cc cc cc cc cc cc cc 0f 1f 44 00 00 55 48 89 e5 48 81 ec 00 00 00 00 53 41 55 41 56 41 57 6a 00 31 c0 48 8b 47 28 <48> 8b 40 00 8b 80 00 01 00 00 5b 41 5f 41 5e 41 5d 5b c9 c3 cc cc
RSP: 0018:ffffc90000f0fce8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000018
RDX: ffffffffa006c7dc RSI: ffffc90000ea5038 RDI: ffffc90000f0fde0
RBP: ffffc90000f0fd10 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000001 R11: ffff88810dbda100 R12: 0000000000029910
R13: 0000000000000001 R14: ffffc90000f0fdd8 R15: 0000000000000001
FS:  00007f7d2e3f3700(0000) GS:ffff88812c100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000010c159000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400