RAX: 0000000000000000 RBX: 00007fcf9db36f60 RCX: 00007fcf9da240e9 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003 RBP: 00007fcf9cb9a1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff8ef9abaf R14: 00007fcf9cb9a300 R15: 0000000000022000 ---[ end trace 096df66d5f39735e ]--- ================================================================== 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 ffff88810f64e098 by task syz-executor.1/1781 CPU: 1 PID: 1781 Comm: syz-executor.1 Tainted: G W 5.10.114-syzkaller-00659-g2ed28105c6c4 #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: 0033:0x7fcf9da240e9 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:00007fcf9cb9a168 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007fcf9db36f60 RCX: 00007fcf9da240e9 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003 RBP: 00007fcf9cb9a1d0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00007fff8ef9abaf R14: 00007fcf9cb9a300 R15: 0000000000022000 Allocated by task 1781: 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 1781: 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 ffff88810f64e080 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 24 bytes inside of 96-byte region [ffff88810f64e080, ffff88810f64e0e0) The buggy address belongs to the page: page:ffffea00043d9380 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88810f64ef80 pfn:0x10f64e flags: 0x8000000000000200(slab) raw: 8000000000000200 ffffea000442f140 0000000d0000000d ffff888100043680 raw: ffff88810f64ef80 000000008020001e 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 997, ts 82938535758, free_ts 82938302249 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:4067 __alloc_pages_nodemask+0x3b6/0x890 mm/page_alloc.c:5117 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] __iomap_dio_rw+0x201/0x10d0 fs/iomap/direct-io.c:446 iomap_dio_rw+0x35/0x80 fs/iomap/direct-io.c:611 ext4_dio_read_iter fs/ext4/file.c:79 [inline] ext4_file_read_iter+0x3c8/0x4d0 fs/ext4/file.c:131 call_read_iter include/linux/fs.h:1941 [inline] generic_file_splice_read+0x479/0x760 fs/splice.c:311 do_splice_to fs/splice.c:788 [inline] splice_direct_to_actor+0x42e/0xbd0 fs/splice.c:867 do_splice_direct+0x2a0/0x3f0 fs/splice.c:976 do_sendfile+0x991/0x1110 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0x1ce/0x230 fs/read_write.c:1304 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+0x6a/0x220 mm/page_alloc.c:3345 __put_single_page mm/swap.c:102 [inline] __put_page+0xb1/0xd0 mm/swap.c:133 put_page include/linux/mm.h:1253 [inline] generic_pipe_buf_release+0xad/0xd0 fs/pipe.c:209 pipe_buf_release include/linux/pipe_fs_i.h:201 [inline] iter_file_splice_write+0xaa0/0x10c0 fs/splice.c:701 do_splice_from fs/splice.c:764 [inline] direct_splice_actor+0xfe/0x130 fs/splice.c:933 splice_direct_to_actor+0x4f4/0xbd0 fs/splice.c:888 do_splice_direct+0x2a0/0x3f0 fs/splice.c:976 do_sendfile+0x991/0x1110 fs/read_write.c:1257 __do_sys_sendfile64 fs/read_write.c:1318 [inline] __se_sys_sendfile64 fs/read_write.c:1304 [inline] __x64_sys_sendfile64+0x1ce/0x230 fs/read_write.c:1304 do_syscall_64+0x34/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Memory state around the buggy address: ffff88810f64df80: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc ffff88810f64e000: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff88810f64e080: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff88810f64e100: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff88810f64e180: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ==================================================================