KASAN: use-after-free Read in __cgroup_bpf

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
android-5-10	KASAN: use-after-free Read in __cgroup_bpf_attach (3)				1	836d	836d	0/2	auto-obsoleted due to no activity on 2022/11/06 11:00
android-5-10	KASAN: use-after-free Read in __cgroup_bpf_attach				2	1094d	1097d	0/2	auto-closed as invalid on 2022/02/20 17:36
==================================================================
BUG: KASAN: use-after-free in prog_list_prog kernel/bpf/cgroup.c:174 [inline]
BUG: KASAN: use-after-free in prog_list_length kernel/bpf/cgroup.c:187 [inline]
BUG: KASAN: use-after-free in __cgroup_bpf_attach+0x5c1/0xd20 kernel/bpf/cgroup.c:467
Read of size 8 at addr ffff88811186d618 by task syz-executor.3/9955

CPU: 1 PID: 9955 Comm: syz-executor.3 Tainted: G        W         5.10.110-syzkaller-01300-ge08dd85cc95e #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_lvl+0x1e2/0x24b lib/dump_stack.c:118
 print_address_description+0x81/0x3c0 mm/kasan/report.c:233
 __kasan_report mm/kasan/report.c:419 [inline]
 kasan_report+0x1a4/0x1f0 mm/kasan/report.c:436
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report_generic.c:309
 prog_list_prog kernel/bpf/cgroup.c:174 [inline]
 prog_list_length kernel/bpf/cgroup.c:187 [inline]
 __cgroup_bpf_attach+0x5c1/0xd20 kernel/bpf/cgroup.c:467
 cgroup_bpf_attach+0x4a/0x70 kernel/cgroup/cgroup.c:6620
 cgroup_bpf_link_attach+0x239/0x4a0 kernel/bpf/cgroup.c:934
 link_create+0x540/0x6e0 kernel/bpf/syscall.c:4092
 __do_sys_bpf+0x528/0x6c0 kernel/bpf/syscall.c:4497
 __se_sys_bpf kernel/bpf/syscall.c:4383 [inline]
 __x64_sys_bpf+0x7a/0x90 kernel/bpf/syscall.c:4383
 do_syscall_64+0x34/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fe62a2880e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe6293fe168 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fe62a39af60 RCX: 00007fe62a2880e9
RDX: 0000000000000010 RSI: 0000000020000000 RDI: 000000000000001c
RBP: 00007fe62a2e208d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff6111118f R14: 00007fe6293fe300 R15: 0000000000022000

Allocated by task 9911:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:428 [inline]
 ____kasan_kmalloc+0xdc/0x110 mm/kasan/common.c:507
 __kasan_kmalloc+0x9/0x10 mm/kasan/common.c:516
 kasan_kmalloc include/linux/kasan.h:269 [inline]
 kmem_cache_alloc_trace+0x1dd/0x330 mm/slub.c:2983
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:664 [inline]
 cgroup_bpf_link_attach+0x12e/0x4a0 kernel/bpf/cgroup.c:918
 link_create+0x540/0x6e0 kernel/bpf/syscall.c:4092
 __do_sys_bpf+0x528/0x6c0 kernel/bpf/syscall.c:4497
 __se_sys_bpf kernel/bpf/syscall.c:4383 [inline]
 __x64_sys_bpf+0x7a/0x90 kernel/bpf/syscall.c:4383
 do_syscall_64+0x34/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 9911:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track+0x4c/0x80 mm/kasan/common.c:46
 kasan_set_free_info+0x23/0x40 mm/kasan/generic.c:357
 ____kasan_slab_free+0x121/0x160 mm/kasan/common.c:360
 __kasan_slab_free+0x11/0x20 mm/kasan/common.c:368
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:1604 [inline]
 slab_free_freelist_hook+0xcc/0x1a0 mm/slub.c:1630
 slab_free mm/slub.c:3212 [inline]
 kfree+0xc3/0x290 mm/slub.c:4200
 bpf_cgroup_link_dealloc+0x15/0x20 kernel/bpf/cgroup.c:849
 bpf_link_free kernel/bpf/syscall.c:2354 [inline]
 bpf_link_put+0x243/0x270 kernel/bpf/syscall.c:2376
 bpf_link_release+0x3b/0x40 kernel/bpf/syscall.c:2384
 __fput+0x348/0x7c0 fs/file_table.c:281
 ____fput+0x15/0x20 fs/file_table.c:314
 task_work_run+0x147/0x1b0 kernel/task_work.c:154
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_user_mode_loop+0xc8/0xe0 kernel/entry/common.c:164
 exit_to_user_mode_prepare kernel/entry/common.c:191 [inline]
 syscall_exit_to_user_mode+0x77/0xa0 kernel/entry/common.c:266
 do_syscall_64+0x40/0x70 arch/x86/entry/common.c:56
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff88811186d600
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
 96-byte region [ffff88811186d600, ffff88811186d660)
The buggy address belongs to the page:
page:ffffea0004461b40 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811186d400 pfn:0x11186d
flags: 0x8000000000000200(slab)
raw: 8000000000000200 ffffea000472c4c8 ffffea0004197148 ffff888100043680
raw: ffff88811186d400 000000000020001a 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 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 8895, ts 253440350420, free_ts 252855031115
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2385 [inline]
 prep_new_page mm/page_alloc.c:2391 [inline]
 get_page_from_freelist+0x745/0x760 mm/page_alloc.c:4063
 __alloc_pages_nodemask+0x3b6/0x890 mm/page_alloc.c:5113
 alloc_slab_page mm/slub.c:1815 [inline]
 allocate_slab+0x78/0x540 mm/slub.c:1817
 new_slab mm/slub.c:1878 [inline]
 new_slab_objects mm/slub.c:2637 [inline]
 ___slab_alloc+0x131/0x2e0 mm/slub.c:2800
 __slab_alloc+0x63/0xa0 mm/slub.c:2840
 slab_alloc_node mm/slub.c:2922 [inline]
 slab_alloc mm/slub.c:2964 [inline]
 kmem_cache_alloc_trace+0x20e/0x330 mm/slub.c:2981
 kmem_cache_alloc_node_trace include/linux/slab.h:440 [inline]
 kmalloc_node include/linux/slab.h:570 [inline]
 kzalloc_node include/linux/slab.h:675 [inline]
 __get_vm_area_node+0x134/0x200 mm/vmalloc.c:2077
 __vmalloc_node_range+0xd5/0x6d0 mm/vmalloc.c:2560
 __vmalloc_node mm/vmalloc.c:2608 [inline]
 vzalloc+0x78/0x90 mm/vmalloc.c:2661
 bpf_check+0x1b9/0x10f10 kernel/bpf/verifier.c:12346
 bpf_prog_load+0x12b0/0x1b70 kernel/bpf/syscall.c:2233
 __do_sys_bpf+0x441/0x6c0 kernel/bpf/syscall.c:4427
 __se_sys_bpf kernel/bpf/syscall.c:4383 [inline]
 __x64_sys_bpf+0x7a/0x90 kernel/bpf/syscall.c:4383
 do_syscall_64+0x34/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1331 [inline]
 free_pcp_prepare+0x18c/0x1c0 mm/page_alloc.c:1405
 free_unref_page_prepare mm/page_alloc.c:3291 [inline]
 free_unref_page_list+0x112/0x5d0 mm/page_alloc.c:3361
 release_pages+0xb14/0xb50 mm/swap.c:1081
 free_pages_and_swap_cache+0x97/0xb0 mm/swap_state.c:356
 tlb_batch_pages_flush mm/mmu_gather.c:49 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:242 [inline]
 tlb_flush_mmu+0x8a0/0xa80 mm/mmu_gather.c:249
 tlb_finish_mmu+0xd2/0x1f0 mm/mmu_gather.c:328
 exit_mmap+0x319/0x5c0 mm/mmap.c:3328
 __mmput+0x95/0x2c0 kernel/fork.c:1133
 mmput+0x4b/0x50 kernel/fork.c:1154
 exit_mm+0x5cd/0x790 kernel/exit.c:489
 do_exit+0x614/0x2360 kernel/exit.c:800
 do_group_exit+0x13a/0x300 kernel/exit.c:910
 __do_sys_exit_group kernel/exit.c:921 [inline]
 __se_sys_exit_group kernel/exit.c:919 [inline]
 __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:919
 do_syscall_64+0x34/0x70 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Memory state around the buggy address:
 ffff88811186d500: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88811186d580: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88811186d600: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                            ^
 ffff88811186d680: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88811186d700: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
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