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KASAN: null-ptr-deref Read in tcf_idrinfo_destroy

Status: premoderation: reported on 2026/02/16 01:12
Reported-by: syzbot+ca2ad5e6538adae4f1d3@syzkaller.appspotmail.com
First crash: 110d, last: 10h57m
▶ ▼ Similar bugs (4)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy 11 7 64d 161d 0/2 premoderation: reported on 2025/12/27 14:00
android-54 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy 11 C 11829 376d 1122d 0/2 upstream: reported C repro on 2023/05/10 22:23
upstream KASAN: null-ptr-deref Read in tcf_idrinfo_destroy net 11 C 115 1887d 2077d 20/29 fixed on 2021/04/09 19:46
upstream BUG: unable to handle kernel paging request in tcf_idrinfo_destroy net 8 1 179d 175d 29/29 fixed on 2026/05/06 16:40

Sample crash report:
==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:71 [inline]
BUG: KASAN: null-ptr-deref in atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
BUG: KASAN: null-ptr-deref in __tcf_idr_release net/sched/act_api.c:162 [inline]
BUG: KASAN: null-ptr-deref in tcf_idrinfo_destroy+0xbf/0x220 net/sched/act_api.c:589
Read of size 4 at addr 0000000000000010 by task kworker/u4:1/9

CPU: 0 PID: 9 Comm: kworker/u4:1 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: netns cleanup_net
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 __kasan_report mm/kasan/report.c:439 [inline]
 kasan_report+0xd8/0x130 mm/kasan/report.c:452
 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:71 [inline]
 atomic_read include/asm-generic/atomic-instrumented.h:27 [inline]
 __tcf_idr_release net/sched/act_api.c:162 [inline]
 tcf_idrinfo_destroy+0xbf/0x220 net/sched/act_api.c:589
 tc_action_net_exit include/net/act_api.h:151 [inline]
 gact_exit_net+0xe3/0x150 net/sched/act_gact.c:278
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x603/0xb80 net/core/net_namespace.c:609
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
==================================================================
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: 9 Comm: kworker/u4:1 Tainted: G    B   W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: netns cleanup_net
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline]
RIP: 0010:atomic_read include/asm-generic/atomic-instrumented.h:28 [inline]
RIP: 0010:__tcf_idr_release net/sched/act_api.c:162 [inline]
RIP: 0010:tcf_idrinfo_destroy+0xc6/0x220 net/sched/act_api.c:589
Code: 40 e8 fe e2 a4 fe 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 01 11 ea 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:ffffc90000097b60 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff8881067d88b0 RCX: 0000000000000286
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90000097c08 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0dcfa48 R12: fffffffffffffff0
R13: 0000000000000010 R14: ffffffff86af71b0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2c0784 CR3: 0000000122880000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tc_action_net_exit include/net/act_api.h:151 [inline]
 gact_exit_net+0xe3/0x150 net/sched/act_gact.c:278
 ops_exit_list net/core/net_namespace.c:190 [inline]
 cleanup_net+0x603/0xb80 net/core/net_namespace.c:609
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
Modules linked in:
---[ end trace 19da187badd5f82c ]---
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline]
RIP: 0010:atomic_read include/asm-generic/atomic-instrumented.h:28 [inline]
RIP: 0010:__tcf_idr_release net/sched/act_api.c:162 [inline]
RIP: 0010:tcf_idrinfo_destroy+0xc6/0x220 net/sched/act_api.c:589
Code: 40 e8 fe e2 a4 fe 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 01 11 ea 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:ffffc90000097b60 EFLAGS: 00010202
RAX: 0000000000000002 RBX: ffff8881067d88b0 RCX: 0000000000000286
RDX: 0000000000000000 RSI: 0000000000000002 RDI: 00000000ffffffff
RBP: ffffc90000097c08 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffffbfff0dcfa48 R12: fffffffffffffff0
R13: 0000000000000010 R14: ffffffff86af71b0 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f70b7a2e540 CR3: 000000011f337000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	40 e8 fe e2 a4 fe    	rex call 0xfea4e304
   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 01 11 ea fd       	call   0xfdea1124
  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

Crashes (17):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/06 09:33 android13-5.10-lts 4a079a5d30eb cc095639 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/05/31 07:58 android13-5.10-lts 4a079a5d30eb 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/05/29 21:16 android13-5.10-lts 4a079a5d30eb 6b4a8443 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/05/27 09:30 android13-5.10-lts f5a34916f66d 2b01f00e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/05/25 03:57 android13-5.10-lts f5a34916f66d c69befb3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/05/18 14:02 android13-5.10-lts f5a34916f66d 55156e84 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/05/15 13:08 android13-5.10-lts 1b32327554da 9cd3beaa .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/05/12 00:47 android13-5.10-lts 1b32327554da d168f260 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/05/08 11:21 android13-5.10-lts 5feb5545d40a 5633175a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/04/26 00:03 android13-5.10-lts d8c55bf860fd 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/04/19 16:01 android13-5.10-lts cc0ae2abdc73 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/04/17 10:58 android13-5.10-lts cc0ae2abdc73 de0a551d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/04/10 23:39 android13-5.10-lts cc0ae2abdc73 38c8e246 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/04/07 06:49 android13-5.10-lts cc0ae2abdc73 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/04/06 20:19 android13-5.10-lts cc0ae2abdc73 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/04/03 09:26 android13-5.10-lts cc0ae2abdc73 4440e7c2 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
2026/02/16 01:11 android13-5.10-lts e8b14e1cefe8 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 KASAN: null-ptr-deref Read in tcf_idrinfo_destroy
* Struck through repros no longer work on HEAD.