================================================================== BUG: KASAN: use-after-free in snd_pcm_oss_poll+0x91c/0xab0 sound/core/oss/pcm_oss.c:2849 Read of size 8 at addr ffff8880264361e0 by task syz-executor.0/6036 CPU: 1 PID: 6036 Comm: syz-executor.0 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_pcm_oss_poll+0x91c/0xab0 sound/core/oss/pcm_oss.c:2849 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: 0033:0x7fb8e908c0c9 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:00007fb8e9df4218 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007fb8e91ac128 RCX: 00007fb8e908c0c9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fb8e91ac128 RBP: 00007fb8e91ac120 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb8e91ac12c R13: 00007fff046ef9bf R14: 00007fb8e9df4300 R15: 0000000000022000 Allocated by task 6027: 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] kzalloc include/linux/slab.h:720 [inline] snd_pcm_oss_open_file sound/core/oss/pcm_oss.c:2433 [inline] snd_pcm_oss_open.part.0+0x558/0x1330 sound/core/oss/pcm_oss.c:2535 snd_pcm_oss_open+0x44/0x60 sound/core/oss/pcm_oss.c:2499 soundcore_open+0x452/0x620 sound/sound_core.c:593 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 6033: 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_pcm_oss_release_file sound/core/oss/pcm_oss.c:2415 [inline] snd_pcm_oss_release_file sound/core/oss/pcm_oss.c:2405 [inline] snd_pcm_oss_release+0x182/0x300 sound/core/oss/pcm_oss.c:2592 __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 ffff8880264361e0 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of 16-byte region [ffff8880264361e0, ffff8880264361f0) The buggy address belongs to the physical page: page:ffffea0000990d80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x26436 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffff8880124413c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000800080 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 5116, tgid 5116 (syz-executor.3), ts 317817638448, free_ts 317817412982 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] apparmor_sk_alloc_security+0x87/0x150 security/apparmor/lsm.c:830 security_sk_alloc+0x54/0xb0 security/security.c:2361 sk_prot_alloc+0xdd/0x290 net/core/sock.c:2041 sk_alloc+0x3a/0x7f0 net/core/sock.c:2091 inet6_create net/ipv6/af_inet6.c:192 [inline] inet6_create+0x373/0x10a0 net/ipv6/af_inet6.c:119 __sock_create+0x358/0x810 net/socket.c:1515 sock_create net/socket.c:1566 [inline] __sys_socket_create net/socket.c:1603 [inline] __sys_socket_create net/socket.c:1588 [inline] __sys_socket+0x133/0x250 net/socket.c:1636 __do_sys_socket net/socket.c:1649 [inline] __se_sys_socket net/socket.c:1647 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1647 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 __vfree+0x3c/0xd0 mm/vmalloc.c:2794 vfree+0x5e/0x90 mm/vmalloc.c:2825 copy_entries_to_user net/ipv4/netfilter/ip_tables.c:868 [inline] get_entries net/ipv4/netfilter/ip_tables.c:1024 [inline] do_ipt_get_ctl+0x802/0x9e0 net/ipv4/netfilter/ip_tables.c:1663 nf_getsockopt+0x76/0xd0 net/netfilter/nf_sockopt.c:116 ip_getsockopt+0x189/0x1e0 net/ipv4/ip_sockglue.c:1797 tcp_getsockopt+0x99/0x100 net/ipv4/tcp.c:4407 __sys_getsockopt+0x21a/0x6a0 net/socket.c:2290 __do_sys_getsockopt net/socket.c:2305 [inline] __se_sys_getsockopt net/socket.c:2302 [inline] __x64_sys_getsockopt+0xbe/0x160 net/socket.c:2302 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 Memory state around the buggy address: ffff888026436080: fa fb fc fc fa fb fc fc fa fb fc fc 00 00 fc fc ffff888026436100: 00 00 fc fc 00 00 fc fc fa fb fc fc fa fb fc fc >ffff888026436180: 00 00 fc fc 00 00 fc fc 00 00 fc fc fa fb fc fc ^ ffff888026436200: fa fb fc fc fa fb fc fc 00 00 fc fc 00 00 fc fc ffff888026436280: fa fb fc fc 00 00 fc fc fa fb fc fc 00 00 fc fc ==================================================================