================================================================== BUG: KASAN: use-after-free in snd_rawmidi_poll+0x559/0x680 sound/core/rawmidi.c:1655 Read of size 8 at addr ffff88801cdcbfc8 by task syz-executor.1/29367 CPU: 1 PID: 29367 Comm: syz-executor.1 Not tainted 6.2.0-rc3-next-20230112-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:306 [inline] print_report+0x15e/0x45d mm/kasan/report.c:417 kasan_report+0xc0/0xf0 mm/kasan/report.c:517 snd_rawmidi_poll+0x559/0x680 sound/core/rawmidi.c:1655 vfs_poll include/linux/poll.h:88 [inline] io_poll_check_events io_uring/poll.c:279 [inline] io_poll_task_func+0x3a6/0x1220 io_uring/poll.c:327 handle_tw_list+0xa8/0x460 io_uring/io_uring.c:1169 tctx_task_work+0x12e/0x530 io_uring/io_uring.c:1224 task_work_run+0x16f/0x270 kernel/task_work.c:179 get_signal+0x1c7/0x24f0 kernel/signal.c:2635 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fb50068c0c9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 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 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb50130c168 EFLAGS: 00000246 ORIG_RAX: 0000000000000013 RAX: fffffffffffffe00 RBX: 00007fb5007ac050 RCX: 00007fb50068c0c9 RDX: 0000000000000001 RSI: 0000000020000680 RDI: 0000000000000006 RBP: 00007fb5006e7ae9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fff508a3a9f R14: 00007fb50130c300 R15: 0000000000022000 Allocated by task 29358: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:371 [inline] ____kasan_kmalloc mm/kasan/common.c:330 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:380 kmalloc include/linux/slab.h:580 [inline] snd_rawmidi_open+0x39a/0xb70 sound/core/rawmidi.c:482 snd_open+0x223/0x460 sound/core/sound.c:169 chrdev_open+0x26a/0x770 fs/char_dev.c:414 do_dentry_open+0x6cc/0x13f0 fs/open.c:883 do_open fs/namei.c:3558 [inline] path_openat+0x1bc1/0x2b40 fs/namei.c:3715 do_filp_open+0x1ba/0x410 fs/namei.c:3742 do_sys_openat2+0x16d/0x4c0 fs/open.c:1311 do_sys_open fs/open.c:1327 [inline] __do_sys_openat fs/open.c:1343 [inline] __se_sys_openat fs/open.c:1338 [inline] __x64_sys_openat+0x143/0x1f0 fs/open.c:1338 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 29367: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:518 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0xaf/0x2d0 mm/slub.c:3800 snd_rawmidi_release+0x6a/0xf0 sound/core/rawmidi.c:619 __fput+0x27c/0xa90 fs/file_table.c:321 task_work_run+0x16f/0x270 kernel/task_work.c:179 get_signal+0x1c7/0x24f0 kernel/signal.c:2635 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd The buggy address belongs to the object at ffff88801cdcbfc0 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 8 bytes inside of 32-byte region [ffff88801cdcbfc0, ffff88801cdcbfe0) The buggy address belongs to the physical page: page:ffffea00007372c0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1cdcb anon flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffff888012441500 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000400040 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 0x112820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_HARDWALL), pid 23971, tgid 23969 (syz-executor.1), ts 1746748766380, free_ts 1746728337355 prep_new_page mm/page_alloc.c:2549 [inline] get_page_from_freelist+0x11bb/0x2d50 mm/page_alloc.c:4324 __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5590 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2281 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x350 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292 __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x136/0x330 mm/slub.c:3491 kmalloc_trace+0x26/0x60 mm/slab_common.c:1061 kmalloc include/linux/slab.h:580 [inline] kzalloc include/linux/slab.h:720 [inline] ref_tracker_alloc+0x158/0x560 lib/ref_tracker.c:85 __netdev_tracker_alloc include/linux/netdevice.h:4020 [inline] netdev_hold include/linux/netdevice.h:4049 [inline] dst_init+0xe4/0x520 net/core/dst.c:52 dst_alloc+0x16f/0x1f0 net/core/dst.c:96 rt_dst_alloc+0x55/0x430 net/ipv4/route.c:1633 __mkroute_output net/ipv4/route.c:2592 [inline] ip_route_output_key_hash_rcu+0x899/0x2c20 net/ipv4/route.c:2814 ip_route_output_key_hash+0x18f/0x340 net/ipv4/route.c:2643 __ip_route_output_key include/net/route.h:140 [inline] ip_route_output_flow+0x27/0x150 net/ipv4/route.c:2873 udp_sendmsg+0x1963/0x2830 net/ipv4/udp.c:1231 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1451 [inline] free_pcp_prepare+0x4d0/0x910 mm/page_alloc.c:1501 free_unref_page_prepare mm/page_alloc.c:3387 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3482 __vunmap+0x7fe/0xc00 mm/vmalloc.c:2746 free_work+0x5c/0x80 mm/vmalloc.c:100 process_one_work+0x9bf/0x1750 kernel/workqueue.c:2293 worker_thread+0x669/0x1090 kernel/workqueue.c:2440 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Memory state around the buggy address: ffff88801cdcbe80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ffff88801cdcbf00: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc >ffff88801cdcbf80: fa fb fb fb fc fc fc fc fa fb fb fb fc fc fc fc ^ ffff88801cdcc000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88801cdcc080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================