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BUG: unable to handle kernel NULL pointer dereference in check_preemption_disabled (3)

Status: fixed on 2020/07/17 17:58
Subsystems: ext4
[Documentation on labels]
Fix commit: 3021e69219e2 kcov: check kcov_softirq in kcov_remote_stop()
First crash: 1570d, last: 1570d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream BUG: unable to handle kernel NULL pointer dereference in check_preemption_disabled (2) usb 1 1572d 1572d 0/28 closed as invalid on 2020/06/16 10:33
upstream BUG: unable to handle kernel NULL pointer dereference in check_preemption_disabled usb 1 1579d 1579d 0/28 closed as invalid on 2020/06/10 12:27

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 a00a3067 P4D a00a3067 PUD 5f1da067 PMD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 19287 Comm: syz-executor.3 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:ffffc90007dbf820 EFLAGS: 00010246
RAX: ffffffff839f8336 RBX: 000000000000007f RCX: ffff888092b0a140
RDX: 0000000000000000 RSI: ffffffff8903523f RDI: ffffffff88e90cfe
RBP: ffff8880a719d280 R08: ffffffff81f976d5 R09: ffffed1015d070fc
R10: ffffed1015d070fc R11: 0000000000000000 R12: 0000000000000001
R13: ffff88809af1e668 R14: ffffffff8903523f R15: ffffffff88e90cfe
FS:  00007f36ea3e2700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000009f730000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 check_preemption_disabled+0x16/0x240 lib/smp_processor_id.c:13
 rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:314 [inline]
 rcu_is_watching+0x1c/0xa0 kernel/rcu/tree.c:1079
 rcu_read_unlock include/linux/rcupdate.h:684 [inline]
 ext4_get_group_desc+0x28f/0x420 fs/ext4/balloc.c:284
 recently_deleted fs/ext4/ialloc.c:678 [inline]
 find_inode_bit+0x28a/0x660 fs/ext4/ialloc.c:724
 __ext4_new_inode+0x1003/0x5940 fs/ext4/ialloc.c:927
 ext4_create+0x1eb/0x450 fs/ext4/namei.c:2614
 lookup_open fs/namei.c:3081 [inline]
 open_last_lookups fs/namei.c:3155 [inline]
 path_openat+0x17ee/0x38b0 fs/namei.c:3343
 do_filp_open+0x191/0x3a0 fs/namei.c:3373
 do_sys_openat2+0x463/0x770 fs/open.c:1179
 do_sys_open fs/open.c:1195 [inline]
 __do_sys_openat fs/open.c:1209 [inline]
 __se_sys_openat fs/open.c:1204 [inline]
 __x64_sys_openat+0x1c8/0x1f0 fs/open.c:1204
 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:00007f36ea3e1c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00000000004f7ca0 RCX: 000000000045ca59
RDX: 00000000000026e1 RSI: 00000000200000c0 RDI: ffffffffffffff9c
RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000007ab R14: 00000000004ca894 R15: 00007f36ea3e26d4
Modules linked in:
CR2: 0000000000000000
---[ end trace d69aed062e719ddb ]---
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:ffffc90007dbf820 EFLAGS: 00010246
RAX: ffffffff839f8336 RBX: 000000000000007f RCX: ffff888092b0a140
RDX: 0000000000000000 RSI: ffffffff8903523f RDI: ffffffff88e90cfe
RBP: ffff8880a719d280 R08: ffffffff81f976d5 R09: ffffed1015d070fc
R10: ffffed1015d070fc R11: 0000000000000000 R12: 0000000000000001
R13: ffff88809af1e668 R14: ffffffff8903523f R15: ffffffff88e90cfe
FS:  00007f36ea3e2700(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000009f730000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/06/17 19:51 upstream 7ae77150d94d b9f3810b .config console log report ci-upstream-kasan-gce-smack-root
2020/06/17 18:16 upstream 7ae77150d94d b9f3810b .config console log report ci-upstream-kasan-gce-smack-root
2020/06/17 08:52 upstream 7ae77150d94d b9f3810b .config console log report ci-upstream-kasan-gce-smack-root
* Struck through repros no longer work on HEAD.