Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 51 15 00 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd17576938 EFLAGS: 00000246 ORIG_RAX: 0000000000000021 RAX: 0000000000000008 RBX: 0000000000000003 RCX: 00007ffa11e2b159 RDX: 0000000000000960 RSI: 0000000000000008 RDI: 0000000000000006 RBP: 00007ffd17576960 R08: 0000000000000001 R09: 00007ffd17576970 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 R13: 00007ffd17576980 R14: 00007ffd175769c0 R15: 0000000000000000 ---[ end trace 213e5b9155eb9184 ]--- ================================================================== 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 compute_effective_progs+0x1d3/0x6e0 kernel/bpf/cgroup.c:240 Read of size 8 at addr ffff88811d435418 by task syz-executor424/367 CPU: 1 PID: 367 Comm: syz-executor424 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] compute_effective_progs+0x1d3/0x6e0 kernel/bpf/cgroup.c:240 update_effective_progs+0x79/0x320 kernel/bpf/cgroup.c:343 __cgroup_bpf_detach+0x312/0x570 kernel/bpf/cgroup.c:689 bpf_cgroup_link_release+0x94/0x260 kernel/bpf/cgroup.c:833 bpf_link_free kernel/bpf/syscall.c:2350 [inline] bpf_link_put+0x1e9/0x270 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 RIP: 0033:0x7ffa11ded263 Code: c7 c2 c0 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb ba 0f 1f 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 RSP: 002b:00007ffd17576938 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000006 RCX: 00007ffa11ded263 RDX: 0000000000000960 RSI: 0000000000000008 RDI: 0000000000000005 RBP: 00007ffd17576960 R08: 0000000000000001 R09: 00007ffd17576970 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 R13: 00007ffd17576980 R14: 00007ffd175769c0 R15: 0000000000000000 Allocated by task 367: 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 367: 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 ffff88811d435400 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 24 bytes inside of 96-byte region [ffff88811d435400, ffff88811d435460) The buggy address belongs to the page: page:ffffea0004750d40 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d435 flags: 0x8000000000000200(slab) raw: 8000000000000200 dead000000000100 dead000000000122 ffff888100043680 raw: 0000000000000000 0000000080200020 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 367, ts 41183983062, free_ts 0 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 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 page_owner free stack trace missing Memory state around the buggy address: ffff88811d435300: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc ffff88811d435380: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc >ffff88811d435400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88811d435480: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811d435500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: 28 00 sub %al,(%rax) 2: 00 00 add %al,(%rax) 4: 75 05 jne 0xb 6: 48 83 c4 28 add $0x28,%rsp a: c3 retq b: e8 51 15 00 00 callq 0x1561 10: 90 nop 11: 48 89 f8 mov %rdi,%rax 14: 48 89 f7 mov %rsi,%rdi 17: 48 89 d6 mov %rdx,%rsi 1a: 48 89 ca mov %rcx,%rdx 1d: 4d 89 c2 mov %r8,%r10 20: 4d 89 c8 mov %r9,%r8 23: 4c 8b 4c 24 08 mov 0x8(%rsp),%r9 28: 0f 05 syscall * 2a: 48 3d 01 f0 ff ff cmp $0xfffffffffffff001,%rax <-- trapping instruction 30: 73 01 jae 0x33 32: c3 retq 33: 48 c7 c1 c0 ff ff ff mov $0xffffffffffffffc0,%rcx 3a: f7 d8 neg %eax 3c: 64 89 01 mov %eax,%fs:(%rcx) 3f: 48 rex.W