syzbot


BUG: unable to handle kernel NULL pointer dereference in dev_ifconf

Status: fixed on 2020/07/17 17:58
Subsystems: net
[Documentation on labels]
Fix commit: 3021e69219e2 kcov: check kcov_softirq in kcov_remote_stop()
First crash: 1495d, last: 1495d

Sample crash report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 94e7c067 P4D 94e7c067 PUD 88eba067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 4607 Comm: syz-executor.5 Not tainted 5.7.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:252 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x3f/0x60 kernel/kcov.c:202
Code: c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 04 14 00 00 00 74 2c 8b 91 e0 13 00 00 83 fa 02 75 21 48 8b 91 e8 13 00 00 <48> 8b 32 48 8d 7e 01 8b 89 e4 13 00 00 48 39 cf 73 08 48 89 44 f2
RSP: 0018:ffffc9001760fd98 EFLAGS: 00010246
RAX: ffffffff86716d45 RBX: dffffc0000000000 RCX: ffff8880619fc2c0
RDX: 0000000000000000 RSI: 0000000000001927 RDI: 0000000000001928
RBP: 0000000000000000 R08: ffffffff86716d72 R09: fffff52002ec1fac
R10: fffff52002ec1fac R11: 0000000000000000 R12: 0000000000000320
R13: 0000000000000028 R14: 00000000000000c0 R15: 000000000073c058
FS:  00007f88214a1700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000089fa2000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 dev_ifconf+0x105/0x220 net/core/dev_ioctl.c:75
 sock_do_ioctl+0x130/0x260 net/socket.c:1062
 sock_ioctl+0x4aa/0x690 net/socket.c:1199
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl fs/ioctl.c:771 [inline]
 __do_sys_ioctl fs/ioctl.c:780 [inline]
 __se_sys_ioctl+0xf9/0x160 fs/ioctl.c:778
 do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:295
 entry_SYSCALL_64_after_hwframe+0x49/0xb3
RIP: 0033:0x45ca59
Code: 0d b7 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f88214a0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004e9920 RCX: 000000000045ca59
RDX: 0000000000400200 RSI: 0000000000008912 RDI: 0000000000000005
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 000000000000041d R14: 00000000004c6e36 R15: 00007f88214a16d4
Modules linked in:
CR2: 0000000000000000
---[ end trace e669d282aba9a64d ]---
RIP: 0010:__read_once_size include/linux/compiler.h:252 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x3f/0x60 kernel/kcov.c:202
Code: c2 00 01 ff 00 74 11 f7 c2 00 01 00 00 74 35 83 b9 04 14 00 00 00 74 2c 8b 91 e0 13 00 00 83 fa 02 75 21 48 8b 91 e8 13 00 00 <48> 8b 32 48 8d 7e 01 8b 89 e4 13 00 00 48 39 cf 73 08 48 89 44 f2
RSP: 0018:ffffc9001760fd98 EFLAGS: 00010246
RAX: ffffffff86716d45 RBX: dffffc0000000000 RCX: ffff8880619fc2c0
RDX: 0000000000000000 RSI: 0000000000001927 RDI: 0000000000001928
RBP: 0000000000000000 R08: ffffffff86716d72 R09: fffff52002ec1fac
R10: fffff52002ec1fac R11: 0000000000000000 R12: 0000000000000320
R13: 0000000000000028 R14: 00000000000000c0 R15: 000000000073c058
FS:  00007f88214a1700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f074a323000 CR3: 0000000089fa2000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/17 07:32 upstream 7ae77150d94d b9f3810b .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.