syzbot


KASAN: use-after-free Read in cpu_map_enqueue

Status: premoderation: reported syz repro on 2024/07/17 04:10
Bug presence: origin:lts
[Documentation on labels]
Reported-by: syzbot+e035c31e7dae9526855c@syzkaller.appspotmail.com
First crash: 81d, last: 6d12h
Bug presence (2)
Date Name Commit Repro Result
2024/09/21 lts (merge base) ae9f2a70d69e C [report] KASAN: use-after-free Read in cpu_map_enqueue
2024/09/21 upstream (ToT) 88264981f208 C Didn't crash
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.1 KASAN: use-after-free Read in cpu_map_enqueue 5 25d 70d 0/3 upstream: reported on 2024/07/27 15:55
upstream KASAN: slab-use-after-free Read in cpu_map_enqueue bpf net 3 71d 84d 0/28 moderation: reported on 2024/07/14 11:06

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in bq_enqueue kernel/bpf/cpumap.c:749 [inline]
BUG: KASAN: use-after-free in cpu_map_enqueue+0xb4/0x370 kernel/bpf/cpumap.c:775
Read of size 8 at addr ffff888117457708 by task syz.0.3383/7273

CPU: 0 PID: 7273 Comm: syz.0.3383 Not tainted 6.1.93-syzkaller-00019-g3b95e548676f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x151/0x1b7 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0x158/0x4e0 mm/kasan/report.c:427
 kasan_report+0x13c/0x170 mm/kasan/report.c:531
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:351
 bq_enqueue kernel/bpf/cpumap.c:749 [inline]
 cpu_map_enqueue+0xb4/0x370 kernel/bpf/cpumap.c:775
 __xdp_do_redirect_frame net/core/filter.c:4283 [inline]
 xdp_do_redirect+0x5b0/0xc60 net/core/filter.c:4327
 tun_xdp_act+0xdb/0xc00 drivers/net/tun.c:1625
 tun_build_skb drivers/net/tun.c:1715 [inline]
 tun_get_user+0xb35/0x3a90 drivers/net/tun.c:1818
 tun_chr_write_iter+0x129/0x210 drivers/net/tun.c:2044
 call_write_iter include/linux/fs.h:2274 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x902/0xeb0 fs/read_write.c:584
 ksys_write+0x199/0x2c0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:646
 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5c35d7c9a0
Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d a1 fb 18 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007ffeed09eef8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5c35f35f80 RCX: 00007f5c35d7c9a0
RDX: 0000000000000066 RSI: 0000000020000900 RDI: 00000000000000c8
RBP: 00007f5c35df0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000066 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f5c35f35f80 R14: 00007f5c35f35f80 R15: 000000000000131d
 </TASK>

Allocated by task 7277:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
 ____kasan_kmalloc mm/kasan/common.c:379 [inline]
 __kasan_kmalloc+0x9c/0xb0 mm/kasan/common.c:388
 kasan_kmalloc include/linux/kasan.h:212 [inline]
 __do_kmalloc_node mm/slab_common.c:957 [inline]
 __kmalloc_node+0xb4/0x1e0 mm/slab_common.c:964
 kmalloc_node include/linux/slab.h:582 [inline]
 bpf_map_kmalloc_node+0xd0/0x2c0 kernel/bpf/syscall.c:454
 __cpu_map_entry_alloc kernel/bpf/cpumap.c:445 [inline]
 cpu_map_update_elem+0x28f/0xf50 kernel/bpf/cpumap.c:603
 bpf_map_update_value+0x1a3/0x410 kernel/bpf/syscall.c:190
 map_update_elem+0x500/0x680 kernel/bpf/syscall.c:1428
 __sys_bpf+0x460/0x7f0 kernel/bpf/syscall.c:4975
 __do_sys_bpf kernel/bpf/syscall.c:5091 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:5089 [inline]
 __x64_sys_bpf+0x7c/0x90 kernel/bpf/syscall.c:5089
 x64_sys_call+0x87f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:322
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Freed by task 7278:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2b/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0x131/0x180 mm/kasan/common.c:241
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:249
 kasan_slab_free include/linux/kasan.h:178 [inline]
 slab_free_hook mm/slub.c:1745 [inline]
 slab_free_freelist_hook mm/slub.c:1771 [inline]
 slab_free mm/slub.c:3684 [inline]
 __kmem_cache_free+0x218/0x3b0 mm/slub.c:3697
 kfree+0x7a/0xf0 mm/slab_common.c:1009
 put_cpu_map_entry+0x6e2/0x760 kernel/bpf/cpumap.c:161
 cpu_map_kthread_run+0x2463/0x2520 kernel/bpf/cpumap.c:408
 kthread+0x26d/0x300 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb4/0xc0 mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
 insert_work+0x56/0x310 kernel/workqueue.c:1368
 __queue_work+0x9b6/0xd70 kernel/workqueue.c:1527
 queue_work_on+0x105/0x170 kernel/workqueue.c:1555
 queue_work include/linux/workqueue.h:510 [inline]
 schedule_work include/linux/workqueue.h:571 [inline]
 __cpu_map_entry_replace kernel/bpf/cpumap.c:558 [inline]
 cpu_map_free+0x1e7/0x2c0 kernel/bpf/cpumap.c:641
 bpf_map_free_deferred+0xf7/0x1b0 kernel/bpf/syscall.c:622
 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299
 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446
 kthread+0x26d/0x300 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Second to last potentially related work creation:
 kasan_save_stack+0x3b/0x60 mm/kasan/common.c:45
 __kasan_record_aux_stack+0xb4/0xc0 mm/kasan/generic.c:486
 kasan_record_aux_stack_noalloc+0xb/0x10 mm/kasan/generic.c:496
 __call_rcu_common kernel/rcu/tree.c:2806 [inline]
 call_rcu+0xee/0x1340 kernel/rcu/tree.c:2925
 __cpu_map_entry_replace kernel/bpf/cpumap.c:556 [inline]
 cpu_map_free+0x109/0x2c0 kernel/bpf/cpumap.c:641
 bpf_map_free_deferred+0xf7/0x1b0 kernel/bpf/syscall.c:622
 process_one_work+0x73d/0xcb0 kernel/workqueue.c:2299
 worker_thread+0xa60/0x1260 kernel/workqueue.c:2446
 kthread+0x26d/0x300 kernel/kthread.c:386
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

The buggy address belongs to the object at ffff888117457700
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 8 bytes inside of
 192-byte region [ffff888117457700, ffff8881174577c0)

The buggy address belongs to the physical page:
page:ffffea00045d15c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888117457c00 pfn:0x117457
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 0000000000000000 dead000000000001 ffff888100042c00
raw: ffff888117457c00 000000008010000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 101, tgid 101 (udevd), ts 4277166597, free_ts 0
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x213/0x220 mm/page_alloc.c:2590
 prep_new_page+0x1b/0x110 mm/page_alloc.c:2597
 get_page_from_freelist+0x27ea/0x2870 mm/page_alloc.c:4425
 __alloc_pages+0x3a1/0x780 mm/page_alloc.c:5714
 alloc_slab_page+0x6c/0xf0
 allocate_slab mm/slub.c:1962 [inline]
 new_slab+0x90/0x3e0 mm/slub.c:2015
 ___slab_alloc+0x6f9/0xb80 mm/slub.c:3203
 __slab_alloc+0x5d/0xa0 mm/slub.c:3302
 slab_alloc_node mm/slub.c:3387 [inline]
 __kmem_cache_alloc_node+0x1af/0x250 mm/slub.c:3460
 kmalloc_trace+0x2a/0xa0 mm/slab_common.c:1047
 kmalloc include/linux/slab.h:556 [inline]
 kzalloc include/linux/slab.h:692 [inline]
 kernfs_fop_open+0x350/0xb10 fs/kernfs/file.c:666
 do_dentry_open+0x891/0x1250 fs/open.c:884
 vfs_open+0x73/0x80 fs/open.c:1015
 do_open fs/namei.c:3627 [inline]
 path_openat+0x2532/0x2d60 fs/namei.c:3784
 do_filp_open+0x230/0x480 fs/namei.c:3811
 do_sys_openat2+0x151/0x890 fs/open.c:1341
page_owner free stack trace missing

Memory state around the buggy address:
 ffff888117457600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888117457680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888117457700: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff888117457780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888117457800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
general protection fault, probably for non-canonical address 0xe0e24d3c3edc0398: 0000 [#1] PREEMPT SMP KASAN
KASAN: maybe wild-memory-access in range [0x071289e1f6e01cc0-0x071289e1f6e01cc7]
CPU: 0 PID: 7273 Comm: syz.0.3383 Tainted: G    B              6.1.93-syzkaller-00019-g3b95e548676f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:bq_enqueue kernel/bpf/cpumap.c:751 [inline]
RIP: 0010:cpu_map_enqueue+0x113/0x370 kernel/bpf/cpumap.c:775
Code: e8 03 42 80 3c 30 00 74 08 48 89 df e8 96 c9 24 00 4c 8b 23 4f 8d 74 3c 58 4d 89 f5 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df <41> 0f b6 44 05 00 84 c0 0f 85 a8 01 00 00 4d 01 fc 41 8b 1e bf 08
RSP: 0018:ffffc90000fcf7a8 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: ffffffff86743880 RCX: ffff888122e45100
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: ffffc90000fcf7e0 R08: ffffffff8198105e R09: fffffbfff0f6d8fd
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8881f6e00000
R13: 00e2513c3edc0398 R14: 071289e1f6e01cc6 R15: 0713016000001c6e
FS:  0000555555f1b500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffda120e020 CR3: 0000000114802000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __xdp_do_redirect_frame net/core/filter.c:4283 [inline]
 xdp_do_redirect+0x5b0/0xc60 net/core/filter.c:4327
 tun_xdp_act+0xdb/0xc00 drivers/net/tun.c:1625
 tun_build_skb drivers/net/tun.c:1715 [inline]
 tun_get_user+0xb35/0x3a90 drivers/net/tun.c:1818
 tun_chr_write_iter+0x129/0x210 drivers/net/tun.c:2044
 call_write_iter include/linux/fs.h:2274 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x902/0xeb0 fs/read_write.c:584
 ksys_write+0x199/0x2c0 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:646
 x64_sys_call+0x2f/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f5c35d7c9a0
Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d a1 fb 18 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89
RSP: 002b:00007ffeed09eef8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f5c35f35f80 RCX: 00007f5c35d7c9a0
RDX: 0000000000000066 RSI: 0000000020000900 RDI: 00000000000000c8
RBP: 00007f5c35df0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000066 R11: 0000000000000202 R12: 0000000000000000
R13: 00007f5c35f35f80 R14: 00007f5c35f35f80 R15: 000000000000131d
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bq_enqueue kernel/bpf/cpumap.c:751 [inline]
RIP: 0010:cpu_map_enqueue+0x113/0x370 kernel/bpf/cpumap.c:775
Code: e8 03 42 80 3c 30 00 74 08 48 89 df e8 96 c9 24 00 4c 8b 23 4f 8d 74 3c 58 4d 89 f5 49 c1 ed 03 48 b8 00 00 00 00 00 fc ff df <41> 0f b6 44 05 00 84 c0 0f 85 a8 01 00 00 4d 01 fc 41 8b 1e bf 08
RSP: 0018:ffffc90000fcf7a8 EFLAGS: 00010203
RAX: dffffc0000000000 RBX: ffffffff86743880 RCX: ffff888122e45100
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008
RBP: ffffc90000fcf7e0 R08: ffffffff8198105e R09: fffffbfff0f6d8fd
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff8881f6e00000
R13: 00e2513c3edc0398 R14: 071289e1f6e01cc6 R15: 0713016000001c6e
FS:  0000555555f1b500(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffda120e020 CR3: 0000000114802000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e8 03 42 80 3c       	call   0x3c804208
   5:	30 00                	xor    %al,(%rax)
   7:	74 08                	je     0x11
   9:	48 89 df             	mov    %rbx,%rdi
   c:	e8 96 c9 24 00       	call   0x24c9a7
  11:	4c 8b 23             	mov    (%rbx),%r12
  14:	4f 8d 74 3c 58       	lea    0x58(%r12,%r15,1),%r14
  19:	4d 89 f5             	mov    %r14,%r13
  1c:	49 c1 ed 03          	shr    $0x3,%r13
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	41 0f b6 44 05 00    	movzbl 0x0(%r13,%rax,1),%eax <-- trapping instruction
  30:	84 c0                	test   %al,%al
  32:	0f 85 a8 01 00 00    	jne    0x1e0
  38:	4d 01 fc             	add    %r15,%r12
  3b:	41 8b 1e             	mov    (%r14),%ebx
  3e:	bf                   	.byte 0xbf
  3f:	08                   	.byte 0x8

Crashes (13):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/09/21 17:13 android14-6.1 3b95e548676f 6f888b75 .config console log report syz / log [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in cpu_map_enqueue
2024/09/29 00:10 android14-6.1 110595418159 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf KASAN: use-after-free Read in cpu_map_enqueue
2024/09/29 00:01 android14-6.1 110595418159 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf KASAN: use-after-free Read in cpu_map_enqueue
2024/09/21 10:13 android14-6.1 3b95e548676f 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in cpu_map_enqueue
2024/09/21 10:11 android14-6.1 3b95e548676f 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in cpu_map_enqueue
2024/09/21 10:09 android14-6.1 3b95e548676f 6f888b75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in cpu_map_enqueue
2024/09/16 12:55 android14-6.1 d1f3a046a65d 08d8a733 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf KASAN: use-after-free Read in cpu_map_enqueue
2024/09/10 03:46 android14-6.1 04212acc42d4 784df80e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf KASAN: use-after-free Read in cpu_map_enqueue
2024/09/08 17:02 android14-6.1 27310ed6b677 9750182a .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf KASAN: use-after-free Read in cpu_map_enqueue
2024/07/30 03:41 android14-6.1 7fa70ede91bb 5187fc86 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf KASAN: use-after-free Read in cpu_map_enqueue
2024/07/20 06:23 android14-6.1 6d6afa9d3f8f 890ce4f3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf KASAN: use-after-free Read in cpu_map_enqueue
2024/07/17 04:09 android14-6.1 7de5ae52b126 215bec2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 KASAN: use-after-free Read in cpu_map_enqueue
2024/09/30 01:16 android14-6.1 110595418159 ba29ff75 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1-perf BUG: unable to handle kernel paging request in cpu_map_enqueue
* Struck through repros no longer work on HEAD.