KASAN: use-after-free Read in snd_timer

Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.19	KASAN: use-after-free Read in snd_timer_resolution	C		done	2	1768d	1768d	1/1	fixed on 2020/02/19 00:41
upstream	KASAN: use-after-free Read in snd_timer_resolution sound	C			5	1754d	1771d	15/28	fixed on 2020/02/18 14:31

================================================================== BUG: KASAN: use-after-free in snd_timer_resolution+0xd8/0xf0 sound/core/timer.c:457 Read of size 8 at addr ffff88809890b580 by task syz-executor232/7363 CPU: 1 PID: 7363 Comm: syz-executor232 Not tainted 4.14.166-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x142/0x197 lib/dump_stack.c:58 print_address_description.cold+0x7c/0x1dc mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report mm/kasan/report.c:409 [inline] kasan_report.cold+0xa9/0x2af mm/kasan/report.c:393 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:430 snd_timer_resolution+0xd8/0xf0 sound/core/timer.c:457 snd_seq_info_timer_read+0x96/0x2be sound/core/seq/seq_timer.c:488 snd_info_seq_show+0xcb/0x120 sound/core/info.c:378 seq_read+0x51a/0x1280 fs/seq_file.c:237 proc_reg_read+0xfa/0x170 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:695 [inline] do_loop_readv_writev fs/read_write.c:682 [inline] do_iter_read+0x3e2/0x5b0 fs/read_write.c:919 vfs_readv+0xd3/0x130 fs/read_write.c:981 do_preadv+0x15d/0x200 fs/read_write.c:1065 SYSC_preadv fs/read_write.c:1115 [inline] SyS_preadv+0x31/0x40 fs/read_write.c:1110 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x441979 RSP: 002b:00007ffcf23cf7e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441979 RDX: 0000000000000227 RSI: 00000000200017c0 RDI: 0000000000000004 RBP: 000000000000e2a2 R08: 000000000000000f R09: 0000000000402780 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004026f0 R13: 0000000000402780 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 7359: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc mm/kasan/kasan.c:551 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:529 kmem_cache_alloc_trace+0x152/0x790 mm/slab.c:3618 kmalloc include/linux/slab.h:488 [inline] kzalloc include/linux/slab.h:661 [inline] snd_timer_instance_new+0x4f/0x3c0 sound/core/timer.c:111 snd_timer_open+0x882/0x15e0 sound/core/timer.c:321 snd_seq_timer_open+0x210/0x520 sound/core/seq/seq_timer.c:287 queue_use+0x9e/0x200 sound/core/seq/seq_queue.c:514 snd_seq_queue_alloc+0x2b5/0x490 sound/core/seq/seq_queue.c:199 snd_seq_ioctl_create_queue+0xad/0x2f0 sound/core/seq/seq_clientmgr.c:1528 snd_seq_kernel_client_ctl+0xd7/0x120 sound/core/seq/seq_clientmgr.c:2360 alloc_seq_queue.isra.0+0xcd/0x150 sound/core/seq/oss/seq_oss_init.c:370 snd_seq_oss_open+0x2d7/0x8d0 sound/core/seq/oss/seq_oss_init.c:228 odev_open+0x69/0x90 sound/core/seq/oss/seq_oss.c:138 soundcore_open+0x3f3/0x5a0 sound/sound_core.c:640 chrdev_open+0x207/0x590 fs/char_dev.c:423 do_dentry_open+0x73b/0xeb0 fs/open.c:777 vfs_open+0x105/0x220 fs/open.c:891 do_last fs/namei.c:3425 [inline] path_openat+0x8bd/0x3f70 fs/namei.c:3566 do_filp_open+0x18e/0x250 fs/namei.c:3600 do_sys_open+0x2c5/0x430 fs/open.c:1084 SYSC_openat fs/open.c:1111 [inline] SyS_openat+0x30/0x40 fs/open.c:1105 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 Freed by task 7359: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack+0x45/0xd0 mm/kasan/kasan.c:447 set_track mm/kasan/kasan.c:459 [inline] kasan_slab_free+0x75/0xc0 mm/kasan/kasan.c:524 __cache_free mm/slab.c:3496 [inline] kfree+0xcc/0x270 mm/slab.c:3815 snd_timer_close_locked+0x758/0xb80 sound/core/timer.c:416 snd_timer_close+0x7b/0xe0 sound/core/timer.c:442 snd_seq_timer_close+0x91/0xd0 sound/core/seq/seq_timer.c:326 queue_delete+0x52/0xb0 sound/core/seq/seq_queue.c:147 snd_seq_queue_delete+0x41/0x60 sound/core/seq/seq_queue.c:219 snd_seq_ioctl_delete_queue+0x6a/0x90 sound/core/seq/seq_clientmgr.c:1550 snd_seq_kernel_client_ctl+0xd7/0x120 sound/core/seq/seq_clientmgr.c:2360 delete_seq_queue.part.0+0xa7/0xf0 sound/core/seq/oss/seq_oss_init.c:389 delete_seq_queue sound/core/seq/oss/seq_oss_init.c:385 [inline] snd_seq_oss_release+0x103/0x140 sound/core/seq/oss/seq_oss_init.c:434 odev_release+0x54/0x80 sound/core/seq/oss/seq_oss.c:153 __fput+0x275/0x7a0 fs/file_table.c:210 ____fput+0x16/0x20 fs/file_table.c:244 task_work_run+0x114/0x190 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xa1a/0x2cd0 kernel/exit.c:858 do_group_exit+0x111/0x330 kernel/exit.c:955 SYSC_exit_group kernel/exit.c:966 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:964 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 The buggy address belongs to the object at ffff88809890b580 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 0 bytes inside of 256-byte region [ffff88809890b580, ffff88809890b680) The buggy address belongs to the page: page:ffffea00026242c0 count:1 mapcount:0 mapping:ffff88809890b080 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff88809890b080 0000000000000000 000000010000000c raw: ffffea00023c2f20 ffffea0002a3ef60 ffff8880aa8007c0 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88809890b480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88809890b500: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc >ffff88809890b580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88809890b600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88809890b680: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ==================================================================