debugfs: creating file 'client-51' debugfs: creating file 'proc_info' debugfs: creating file 'device' ================================================================== BUG: KASAN: slab-use-after-free in dvb_device_open+0x33f/0x3b0 drivers/media/dvb-core/dvbdev.c:99 Read of size 8 at addr ffff88802f10a418 by task syz.3.616/8732 CPU: 2 UID: 0 PID: 8732 Comm: syz.3.616 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 dvb_device_open+0x33f/0x3b0 drivers/media/dvb-core/dvbdev.c:99 chrdev_open+0x234/0x6a0 fs/char_dev.c:413 do_dentry_open+0x674/0x1470 fs/open.c:1000 vfs_open_consume+0xcc/0x460 fs/open.c:1131 do_open fs/namei.c:4845 [inline] path_openat+0x1547/0x23f0 fs/namei.c:5010 do_file_open+0x20e/0x430 fs/namei.c:5039 do_sys_openat2+0x163/0x1d0 fs/open.c:1442 do_sys_open fs/open.c:1448 [inline] __do_sys_openat fs/open.c:1464 [inline] __se_sys_openat fs/open.c:1459 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1459 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbd6495fd8e Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08 RSP: 002b:00007fbd65848b28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007fbd658496c0 RCX: 00007fbd6495fd8e RDX: 0000000000000202 RSI: 00007fbd65848c00 RDI: ffffffffffffff9c RBP: 00007fbd65848c00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007fbd64c26038 R14: 00007fbd64c25fa0 R15: 00007ffcefcda0f8 Allocated by task 38: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:409 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5414 [inline] __kmalloc_noprof+0x32f/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] _kmalloc_array_noprof include/linux/slab.h:1211 [inline] security_inode_init_security+0x113/0x370 security/security.c:1361 shmem_mknod+0x2ce/0x480 mm/shmem.c:3841 vfs_mknod+0x3a8/0x7f0 fs/namei.c:5279 handle_create drivers/base/devtmpfs.c:283 [inline] handle drivers/base/devtmpfs.c:435 [inline] devtmpfs_work_loop+0x4a3/0xaed drivers/base/devtmpfs.c:450 devtmpfsd+0x3f/0x50 drivers/base/devtmpfs.c:492 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Freed by task 38: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2748 [inline] slab_free mm/slub.c:6509 [inline] kfree+0x22b/0x6d0 mm/slub.c:6802 security_inode_init_security+0x2bf/0x370 security/security.c:1388 shmem_mknod+0x2ce/0x480 mm/shmem.c:3841 vfs_mknod+0x3a8/0x7f0 fs/namei.c:5279 handle_create drivers/base/devtmpfs.c:283 [inline] handle drivers/base/devtmpfs.c:435 [inline] devtmpfs_work_loop+0x4a3/0xaed drivers/base/devtmpfs.c:450 devtmpfsd+0x3f/0x50 drivers/base/devtmpfs.c:492 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 The buggy address belongs to the object at ffff88802f10a400 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of freed 256-byte region [ffff88802f10a400, ffff88802f10a500) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88802f10a400 pfn:0x2f10a head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000240(workingset|head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000240 ffff88801d042b40 ffffea0000a02d90 ffffea00012e8290 raw: ffff88802f10a400 000000000010000f 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801d042b40 ffffea0000a02d90 ffffea00012e8290 head: ffff88802f10a400 000000000010000f 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 38, tgid 38 (kdevtmpfs), ts 8067079523 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1871 prep_new_page mm/page_alloc.c:1879 [inline] get_page_from_freelist+0x110d/0x35d0 mm/page_alloc.c:3943 __alloc_frozen_pages_noprof+0x2e9/0x32e0 mm/page_alloc.c:5436 alloc_slab_page mm/slub.c:3347 [inline] allocate_slab mm/slub.c:3462 [inline] new_slab+0xa9/0x6e0 mm/slub.c:3513 refill_objects+0xe3/0x410 mm/slub.c:7418 refill_sheaf mm/slub.c:2885 [inline] __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4774 alloc_from_pcs mm/slub.c:4850 [inline] slab_alloc_node mm/slub.c:4984 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_noprof+0x677/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] _kmalloc_array_noprof include/linux/slab.h:1211 [inline] security_inode_init_security+0x113/0x370 security/security.c:1361 shmem_mknod+0x2ce/0x480 mm/shmem.c:3841 vfs_mknod+0x3a8/0x7f0 fs/namei.c:5279 handle_create drivers/base/devtmpfs.c:283 [inline] handle drivers/base/devtmpfs.c:435 [inline] devtmpfs_work_loop+0x4a3/0xaed drivers/base/devtmpfs.c:450 devtmpfsd+0x3f/0x50 drivers/base/devtmpfs.c:492 kthread+0x373/0x450 kernel/kthread.c:436 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page_owner free stack trace missing Memory state around the buggy address: ffff88802f10a300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88802f10a380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88802f10a400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88802f10a480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88802f10a500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================