syzbot


WARNING in free_task

Status: auto-closed as invalid on 2020/01/24 17:39
Reported-by: syzbot+d1f926abddddcacc53c1@syzkaller.appspotmail.com
First crash: 1009d, last: 1005d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in free_task 1 1352d 1352d 0/22 closed as dup on 2018/10/15 07:54

Sample crash report:
WARNING: CPU: 0 PID: 9 at kernel/fork.c:408 free_task+0xf8/0x120 kernel/fork.c:408
audit: type=1804 audit(1569519519.616:430): pid=12427 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op=invalid_pcr cause=open_writers comm="syz-executor.5" name="/root/syzkaller-testdir298694716/syzkaller.Mh9HQv/145/file0" dev="sda1" ino=16532 res=1
Kernel panic - not syncing: panic_on_warn set ...

CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 4.19.75 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x263/0x507 kernel/panic.c:185
 __warn.cold+0x20/0x4a kernel/panic.c:540
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:178 [inline]
 fixup_bug arch/x86/kernel/traps.c:173 [inline]
 do_error_trap+0x204/0x360 arch/x86/kernel/traps.c:296
audit: type=1804 audit(1569519519.616:431): pid=12427 uid=0 auid=4294967295 ses=4294967295 subj=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 op=invalid_pcr cause=ToMToU comm="syz-executor.5" name="/root/syzkaller-testdir298694716/syzkaller.Mh9HQv/145/file0" dev="sda1" ino=16532 res=1
 do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
 invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:1037
RIP: 0010:free_task+0xf8/0x120 kernel/fork.c:408
Code: 48 8b 3d fb 36 3c 08 4c 89 e6 e8 d3 8c 63 00 5b 41 5c 41 5d 5d c3 e8 c7 32 2d 00 4c 89 e7 e8 2f 6f 09 00 eb d6 e8 b8 32 2d 00 <0f> 0b e9 6a ff ff ff e8 0c c6 63 00 eb ab 4c 89 ef e8 02 c6 63 00
RSP: 0018:ffff8880aa237c10 EFLAGS: 00010206
RAX: ffff8880aa226240 RBX: 0000000000000001 RCX: ffffffff813e2f31
RDX: 0000000000000100 RSI: ffffffff813e2fc8 RDI: 0000000000000005
==================================================================
RBP: ffff8880aa237c28 R08: ffff8880aa226240 R09: ffffed10104af698
R10: ffffed10104af697 R11: ffff88808257b4bb R12: ffff88808257a180
BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
BUG: KASAN: null-ptr-deref in read_cred_subscribers kernel/cred.c:78 [inline]
BUG: KASAN: null-ptr-deref in __validate_process_creds+0x1fe/0x300 kernel/cred.c:806
Read of size 4 at addr 0000000000000004 by task syz-executor.1/12406
R13: ffff88808257b4b8 R14: ffff88808efbeda8 R15: ffffffff813fa710

 __put_task_struct+0x20f/0x4c0 kernel/fork.c:689
 put_task_struct include/linux/sched/task.h:96 [inline]
 delayed_put_task_struct+0x1fb/0x350 kernel/exit.c:181
 __rcu_reclaim kernel/rcu/rcu.h:236 [inline]
 rcu_do_batch kernel/rcu/tree.c:2584 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2897 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2864 [inline]
 rcu_process_callbacks+0xba0/0x1a30 kernel/rcu/tree.c:2881
 __do_softirq+0x25c/0x921 kernel/softirq.c:292
 run_ksoftirqd kernel/softirq.c:653 [inline]
 run_ksoftirqd+0x8e/0x110 kernel/softirq.c:645
 smpboot_thread_fn+0x6a3/0xa30 kernel/smpboot.c:164
 kthread+0x354/0x420 kernel/kthread.c:246
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
CPU: 1 PID: 12406 Comm: syz-executor.1 Not tainted 4.19.75 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 kasan_report_error mm/kasan/report.c:352 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x199/0x2ba mm/kasan/report.c:396
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x123/0x190 mm/kasan/kasan.c:267
 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272
 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline]
 read_cred_subscribers kernel/cred.c:78 [inline]
 __validate_process_creds+0x1fe/0x300 kernel/cred.c:806
 validate_creds_for_do_exit+0x22/0x26 kernel/cred.c:841
 do_exit+0x1ece/0x2fa0 kernel/exit.c:923
 do_group_exit+0x135/0x370 kernel/exit.c:979
 get_signal+0x3ec/0x1fc0 kernel/signal.c:2574
 do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x459a29
Code: fd 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fefbbbb9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: 0000000000000010 RBX: 0000000000000003 RCX: 0000000000459a29
RDX: 0000000000000010 RSI: 0000000020000400 RDI: 0000000000000009
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fefbbbba6d4
R13: 00000000004d0d38 R14: 00000000004e11a0 R15: 00000000ffffffff
==================================================================
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (2):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-19 2019/09/26 17:38 linux-4.19.y d573e8a79f70 24d405a3 .config log report
ci2-linux-4-19 2019/09/22 10:16 linux-4.19.y d573e8a79f70 d96e88f3 .config log report