==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:72 [inline]
BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
BUG: KASAN: null-ptr-deref in __tcf_idr_release net/sched/act_api.c:416 [inline]
BUG: KASAN: null-ptr-deref in tcf_idrinfo_destroy+0xbf/0x220 net/sched/act_api.c:902
Read of size 4 at addr 0000000000000010 by task kworker/u4:12/3761

CPU: 0 PID: 3761 Comm: kworker/u4:12 Tainted: G        W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: netns cleanup_net
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_report+0x3d/0x60 mm/kasan/report.c:423
 kasan_report+0x122/0x150 mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
 __kasan_check_read+0x11/0x20 mm/kasan/shadow.c:31
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
 __tcf_idr_release net/sched/act_api.c:416 [inline]
 tcf_idrinfo_destroy+0xbf/0x220 net/sched/act_api.c:902
 tc_action_net_exit include/net/act_api.h:175 [inline]
 gact_exit_net+0xe3/0x150 net/sched/act_gact.c:307
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x635/0xb10 net/core/net_namespace.c:604
 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302
 worker_thread+0xa29/0x11e0 kernel/workqueue.c:2449
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
==================================================================
general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 PID: 3761 Comm: kworker/u4:12 Tainted: G    B   W          syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: netns cleanup_net
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline]
RIP: 0010:__tcf_idr_release net/sched/act_api.c:416 [inline]
RIP: 0010:tcf_idrinfo_destroy+0xc6/0x220 net/sched/act_api.c:902
Code: 40 e8 2e 2b e1 00 48 85 c0 0f 84 1a 01 00 00 49 89 c4 4c 8d 68 20 4c 89 ef be 04 00 00 00 e8 41 5b ab fd 4c 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 ba 00 00 00 45 8b 6d 00 31 ff 44 89 ee
RSP: 0018:ffffc90006b87b60 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff88810d5b4030 RCX: ffff88814a961440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90006b87c08 R08: ffffffff87b717e7 R09: 1ffffffff0f6e2fc
R10: dffffc0000000000 R11: fffffbfff0f6e2fd R12: fffffffffffffff0
R13: 0000000000000010 R14: ffffffff877ab470 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f493217f000 CR3: 0000000123976000 CR4: 00000000003506b0
Call Trace:
 <TASK>
 tc_action_net_exit include/net/act_api.h:175 [inline]
 gact_exit_net+0xe3/0x150 net/sched/act_gact.c:307
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x635/0xb10 net/core/net_namespace.c:604
 process_one_work+0x71f/0xc40 kernel/workqueue.c:2302
 worker_thread+0xa29/0x11e0 kernel/workqueue.c:2449
 kthread+0x281/0x320 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline]
RIP: 0010:__tcf_idr_release net/sched/act_api.c:416 [inline]
RIP: 0010:tcf_idrinfo_destroy+0xc6/0x220 net/sched/act_api.c:902
Code: 40 e8 2e 2b e1 00 48 85 c0 0f 84 1a 01 00 00 49 89 c4 4c 8d 68 20 4c 89 ef be 04 00 00 00 e8 41 5b ab fd 4c 89 e8 48 c1 e8 03 <42> 0f b6 04 38 84 c0 0f 85 ba 00 00 00 45 8b 6d 00 31 ff 44 89 ee
RSP: 0018:ffffc90006b87b60 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff88810d5b4030 RCX: ffff88814a961440
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90006b87c08 R08: ffffffff87b717e7 R09: 1ffffffff0f6e2fc
R10: dffffc0000000000 R11: fffffbfff0f6e2fd R12: fffffffffffffff0
R13: 0000000000000010 R14: ffffffff877ab470 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4931807000 CR3: 000000011908b000 CR4: 00000000003506b0
----------------
Code disassembly (best guess):
   0:	40 e8 2e 2b e1 00    	rex call 0xe12b34
   6:	48 85 c0             	test   %rax,%rax
   9:	0f 84 1a 01 00 00    	je     0x129
   f:	49 89 c4             	mov    %rax,%r12
  12:	4c 8d 68 20          	lea    0x20(%rax),%r13
  16:	4c 89 ef             	mov    %r13,%rdi
  19:	be 04 00 00 00       	mov    $0x4,%esi
  1e:	e8 41 5b ab fd       	call   0xfdab5b64
  23:	4c 89 e8             	mov    %r13,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 38       	movzbl (%rax,%r15,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 ba 00 00 00    	jne    0xf1
  37:	45 8b 6d 00          	mov    0x0(%r13),%r13d
  3b:	31 ff                	xor    %edi,%edi
  3d:	44 89 ee             	mov    %r13d,%esi