syzbot has found a reproducer for the following issue on:
HEAD commit: 0a093b2893c7 Add linux-next specific files for 20230112 git tree: linux-next console+strace: https://syzkaller.appspot.com/x/log.txt?x=13948291480000 kernel config: https://syzkaller.appspot.com/x/.config?x=835f3591019836d5 dashboard link: https://syzkaller.appspot.com/bug?extid=ee73befabe68e7907adf compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=142c4d16480000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10129b5a480000
Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/8111a570d6cb/disk-0a093b28.raw.... vmlinux: https://storage.googleapis.com/syzbot-assets/ecc135b7fc9a/vmlinux-0a093b28.x... kernel image: https://storage.googleapis.com/syzbot-assets/ca8d73b446ea/bzImage-0a093b28.x...
IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+ee73befabe68e7907adf@syzkaller.appspotmail.com
================================================================== 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 ffff88801c509840 by task syz-executor364/5089
CPU: 0 PID: 5089 Comm: syz-executor364 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: <TASK> __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: 0033:0x7f4b05dee34b Code: 0f 05 48 3d 00 f0 ff ff 77 45 c3 0f 1f 40 00 48 83 ec 18 89 7c 24 0c e8 63 fc ff ff 8b 7c 24 0c 41 89 c0 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 44 89 c7 89 44 24 0c e8 a1 fc ff ff 8b 44 RSP: 002b:00007ffc30175fb0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: fffffffffffffff7 RBX: 000000000000000c RCX: 00007f4b05dee34b RDX: ffffffffffffffb8 RSI: 000000000000450e RDI: 000000000000000b RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007ffc30175fe8 R13: 00007f4b05eb7508 R14: 00007ffc30176000 R15: 0000000000000000 </TASK>
Allocated by task 5089: 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 5089: 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 ffff88801c509840 which belongs to the cache kmalloc-16 of size 16 The buggy address is located 0 bytes inside of 16-byte region [ffff88801c509840, ffff88801c509850)
The buggy address belongs to the physical page: page:ffffea0000714240 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1c509 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffff8880124413c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080800080 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 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 1, tgid 1 (swapper/0), ts 12562219376, free_ts 12549200446 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_page_interleave+0x1e/0x200 mm/mempolicy.c:2114 alloc_pages+0x233/0x270 mm/mempolicy.c:2276 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 __do_kmalloc_node mm/slab_common.c:966 [inline] __kmalloc+0x4a/0xd0 mm/slab_common.c:980 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] kobject_get_path+0xc2/0x230 lib/kobject.c:147 kobject_uevent_env+0x257/0x1620 lib/kobject_uevent.c:529 kernel_add_sysfs_param kernel/params.c:816 [inline] param_sysfs_builtin kernel/params.c:851 [inline] param_sysfs_builtin_init+0x321/0x3fd kernel/params.c:985 do_one_initcall+0x141/0x7d0 init/main.c:1306 do_initcall_level init/main.c:1379 [inline] do_initcalls init/main.c:1395 [inline] do_basic_setup init/main.c:1414 [inline] kernel_init_freeable+0x6f9/0x782 init/main.c:1634 kernel_init+0x1e/0x1d0 init/main.c:1522 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 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 kasan_depopulate_vmalloc_pte+0x60/0x80 mm/kasan/shadow.c:372 apply_to_pte_range mm/memory.c:2575 [inline] apply_to_pmd_range mm/memory.c:2619 [inline] apply_to_pud_range mm/memory.c:2655 [inline] apply_to_p4d_range mm/memory.c:2691 [inline] __apply_to_page_range+0x68c/0x1030 mm/memory.c:2725 kasan_release_vmalloc+0xab/0xc0 mm/kasan/shadow.c:486 __purge_vmap_area_lazy+0x897/0x1fa0 mm/vmalloc.c:1776 drain_vmap_area_work+0x56/0xe0 mm/vmalloc.c:1809 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: ffff88801c509700: 00 03 fc fc 00 00 fc fc 00 03 fc fc 00 03 fc fc ffff88801c509780: 00 00 fc fc fb fb fc fc fb fb fc fc fb fb fc fc
ffff88801c509800: 00 01 fc fc 00 01 fc fc fa fb fc fc 00 03 fc fc
^ ffff88801c509880: 00 03 fc fc fa fb fc fc 00 00 fc fc 00 00 fc fc ffff88801c509900: fa fb fc fc fa fb fc fc fa fb fc fc fa fb fc fc ==================================================================