RSP: 002b:00000000f5f030cc EFLAGS: 00000296 ORIG_RAX: 00000000000000bb RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000000000005 ================================================================== RDX: 0000000000000000 RSI: 0000000000000007 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 BUG: KASAN: use-after-free in snd_seq_ioctl_get_subscription+0x241/0x250 sound/core/seq/seq_clientmgr.c:1913 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 Read of size 80 at addr ffff8801d89bd180 by task syz-executor4/31957 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 CPU: 0 PID: 31957 Comm: syz-executor4 Not tainted 4.19.0+ #218 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load_n_noabort+0xf/0x20 mm/kasan/report.c:443 snd_seq_ioctl_get_subscription+0x241/0x250 sound/core/seq/seq_clientmgr.c:1913 snd_seq_ioctl+0x253/0x440 sound/core/seq/seq_clientmgr.c:2138 snd_seq_ioctl_compat+0x16c/0x2d0 sound/core/seq/seq_compat.c:123 __do_compat_sys_ioctl fs/compat_ioctl.c:1052 [inline] __se_compat_sys_ioctl fs/compat_ioctl.c:998 [inline] __ia32_compat_sys_ioctl+0x20e/0x630 fs/compat_ioctl.c:998 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 cgroup: fork rejected by pids controller in /syz2 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f70a29 Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f5f4b0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00000000c0505350 RDX: 0000000020000140 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 31953: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 kmalloc include/linux/slab.h:546 [inline] kzalloc include/linux/slab.h:741 [inline] snd_seq_port_connect+0xe0/0x760 sound/core/seq/seq_ports.c:571 snd_seq_ioctl_subscribe_port+0x1e1/0x320 sound/core/seq/seq_clientmgr.c:1458 snd_seq_ioctl+0x253/0x440 sound/core/seq/seq_clientmgr.c:2138 snd_seq_ioctl_compat+0x16c/0x2d0 sound/core/seq/seq_compat.c:123 __do_compat_sys_ioctl fs/compat_ioctl.c:1052 [inline] __se_compat_sys_ioctl fs/compat_ioctl.c:998 [inline] __ia32_compat_sys_ioctl+0x20e/0x630 fs/compat_ioctl.c:998 CPU: 1 PID: 31950 Comm: syz-executor1 Not tainted 4.19.0+ #218 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 Freed by task 31946: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 fail_dump lib/fault-inject.c:51 [inline] should_fail.cold.4+0xa/0x17 lib/fault-inject.c:149 clear_subscriber_list+0x1ba/0x390 sound/core/seq/seq_ports.c:254 port_delete+0x7c/0x1b0 sound/core/seq/seq_ports.c:270 snd_seq_delete_all_ports+0x5fb/0x940 sound/core/seq/seq_ports.c:333 seq_free_client1.part.9+0xcb/0x270 sound/core/seq/seq_clientmgr.c:262 seq_free_client1 sound/core/seq/seq_clientmgr.c:256 [inline] seq_free_client+0x82/0x100 sound/core/seq/seq_clientmgr.c:285 snd_seq_release+0x51/0xe0 sound/core/seq/seq_clientmgr.c:366 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_32_irqs_on arch/x86/entry/common.c:341 [inline] do_fast_syscall_32+0xcd5/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 The buggy address belongs to the object at ffff8801d89bd180 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 0 bytes inside of 128-byte region [ffff8801d89bd180, ffff8801d89bd200) The buggy address belongs to the page: page:ffffea0007626f40 count:1 mapcount:0 mapping:ffff8801da800640 index:0xffff8801d89bd600 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea0006e19508 ffffea0006ee86c8 ffff8801da800640 __should_failslab+0x124/0x180 mm/failslab.c:32 raw: ffff8801d89bd600 ffff8801d89bd000 0000000100000014 0000000000000000 should_failslab+0x9/0x14 mm/slab_common.c:1578 page dumped because: kasan: bad access detected slab_pre_alloc_hook mm/slab.h:423 [inline] slab_alloc mm/slab.c:3378 [inline] kmem_cache_alloc+0x2be/0x730 mm/slab.c:3552 anon_vma_alloc mm/rmap.c:82 [inline] __anon_vma_prepare+0x3b3/0x6c0 mm/rmap.c:190 Memory state around the buggy address: ffff8801d89bd080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801d89bd100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc anon_vma_prepare include/linux/rmap.h:153 [inline] do_huge_pmd_anonymous_page+0x15b7/0x2040 mm/huge_memory.c:675 >ffff8801d89bd180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801d89bd200: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801d89bd280: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== create_huge_pmd mm/memory.c:3656 [inline] __handle_mm_fault+0x3c97/0x5be0 mm/memory.c:3860 handle_mm_fault+0x54f/0xc70 mm/memory.c:3926 do_user_addr_fault arch/x86/mm/fault.c:1423 [inline] __do_page_fault+0x5e8/0xe60 arch/x86/mm/fault.c:1489 do_page_fault+0xf2/0x7e0 arch/x86/mm/fault.c:1520 page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1139 RIP: 0010:__put_user_4+0x1c/0x30 arch/x86/lib/putuser.S:68 Code: 1f 00 c3 90 66 2e 0f 1f 84 00 00 00 00 00 65 48 8b 1c 25 40 ee 01 00 48 8b 9b 18 14 00 00 48 83 eb 03 48 39 d9 73 3c 0f 1f 00 <89> 01 31 c0 0f 1f 00 c3 66 90 66 2e 0f 1f 84 00 00 00 00 00 65 48 RSP: 0018:ffff88018db9fca8 EFLAGS: 00010293 RAX: 0000000000000004 RBX: 00007fffffffeffd RCX: 0000000020000280 RDX: 000000000000005b RSI: ffffffff81b17e03 RDI: 0000000000000286 RBP: ffff88018db9fda0 R08: 1ffff10031b73f72 R09: 0000000000000008 R10: 0000000000000001 R11: ffff8801ce4dc680 R12: 0000000000000004 R13: 0000000020000280 R14: 0000000000000002 R15: dffffc0000000000 __do_sys_socketpair net/socket.c:1458 [inline] __se_sys_socketpair net/socket.c:1455 [inline] __ia32_sys_socketpair+0x96/0xf0 net/socket.c:1455 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f18a29 Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f5f140cc EFLAGS: 00000296 ORIG_RAX: 0000000000000168 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 0000000000000002 RDX: 0000000000000001 RSI: 0000000020000280 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000