================================================================== 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 ffff888028845c18 by task syz.8.2730/17628 CPU: 1 UID: 0 PID: 17628 Comm: syz.8.2730 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+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1e0 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:411 do_dentry_open+0x6d8/0x1660 fs/open.c:949 vfs_open+0x82/0x3f0 fs/open.c:1081 do_open fs/namei.c:4671 [inline] path_openat+0x208c/0x31a0 fs/namei.c:4830 do_file_open+0x20e/0x430 fs/namei.c:4859 do_sys_openat2+0x10d/0x1e0 fs/open.c:1366 do_sys_open fs/open.c:1372 [inline] __do_sys_openat fs/open.c:1388 [inline] __se_sys_openat fs/open.c:1383 [inline] __x64_sys_openat+0x12d/0x210 fs/open.c:1383 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f069ff5cece 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:00007f06a0f3cb28 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f06a0f3d6c0 RCX: 00007f069ff5cece RDX: 0000000000141000 RSI: 00007f06a0f3cc00 RDI: ffffffffffffff9c RBP: 00007f06a0f3cc00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: cccccccccccccccd R13: 00007f06a0216038 R14: 00007f06a0215fa0 R15: 00007ffed6b8bc68 Allocated by task 8048: 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:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:962 [inline] inode_doinit_use_xattr+0x54/0x330 security/selinux/hooks.c:1377 inode_doinit_with_dentry+0x10e6/0x1320 security/selinux/hooks.c:1571 selinux_d_instantiate+0x26/0x40 security/selinux/hooks.c:6550 security_d_instantiate+0x14c/0x1b0 security/security.c:3601 d_splice_alias_ops+0xd7/0x1320 fs/dcache.c:3074 kernfs_iop_lookup+0x23f/0x2d0 fs/kernfs/dir.c:1256 __lookup_slow+0x251/0x460 fs/namei.c:1916 lookup_slow+0x50/0x70 fs/namei.c:1933 walk_component fs/namei.c:2279 [inline] lookup_last fs/namei.c:2780 [inline] path_lookupat+0x5e8/0xc40 fs/namei.c:2804 filename_lookup+0x202/0x590 fs/namei.c:2833 vfs_statx+0xff/0x3f0 fs/stat.c:353 vfs_fstatat+0x77/0xe0 fs/stat.c:373 __do_sys_newfstatat+0x9d/0x120 fs/stat.c:538 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8048: 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:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2687 [inline] slab_free mm/slub.c:6124 [inline] kfree+0x1f6/0x6b0 mm/slub.c:6442 inode_doinit_use_xattr+0x1e4/0x330 security/selinux/hooks.c:1401 inode_doinit_with_dentry+0x10e6/0x1320 security/selinux/hooks.c:1571 selinux_d_instantiate+0x26/0x40 security/selinux/hooks.c:6550 security_d_instantiate+0x14c/0x1b0 security/security.c:3601 d_splice_alias_ops+0xd7/0x1320 fs/dcache.c:3074 kernfs_iop_lookup+0x23f/0x2d0 fs/kernfs/dir.c:1256 __lookup_slow+0x251/0x460 fs/namei.c:1916 lookup_slow+0x50/0x70 fs/namei.c:1933 walk_component fs/namei.c:2279 [inline] lookup_last fs/namei.c:2780 [inline] path_lookupat+0x5e8/0xc40 fs/namei.c:2804 filename_lookup+0x202/0x590 fs/namei.c:2833 vfs_statx+0xff/0x3f0 fs/stat.c:353 vfs_fstatat+0x77/0xe0 fs/stat.c:373 __do_sys_newfstatat+0x9d/0x120 fs/stat.c:538 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888028845c00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 24 bytes inside of freed 256-byte region [ffff888028845c00, ffff888028845d00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888028845c00 pfn:0x28844 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 ffff88801b842b40 ffffea0000ed5c90 ffffea0000dd5410 raw: ffff888028845c00 000000000010000d 00000000f5000000 0000000000000000 head: 00fff00000000240 ffff88801b842b40 ffffea0000ed5c90 ffffea0000dd5410 head: ffff888028845c00 000000000010000d 00000000f5000000 0000000000000000 head: 00fff00000000001 ffffea0000a21101 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 1, tgid 1 (swapper/0), ts 21506574322, free_ts 12785231342 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1889 prep_new_page mm/page_alloc.c:1897 [inline] get_page_from_freelist+0x111d/0x3140 mm/page_alloc.c:3962 __alloc_frozen_pages_noprof+0x27c/0x2ba0 mm/page_alloc.c:5250 alloc_slab_page mm/slub.c:3255 [inline] allocate_slab mm/slub.c:3444 [inline] new_slab+0xa6/0x6d0 mm/slub.c:3502 refill_objects+0x26b/0x400 mm/slub.c:7134 refill_sheaf mm/slub.c:2804 [inline] alloc_full_sheaf mm/slub.c:2825 [inline] __pcs_replace_empty_main+0x19f/0x600 mm/slub.c:4588 alloc_from_pcs mm/slub.c:4681 [inline] slab_alloc_node mm/slub.c:4815 [inline] __kmalloc_cache_noprof+0x493/0x6f0 mm/slub.c:5334 kmalloc_noprof include/linux/slab.h:962 [inline] kzalloc_noprof include/linux/slab.h:1200 [inline] bus_add_driver+0x92/0x5b0 drivers/base/bus.c:699 driver_register+0x1e2/0x360 drivers/base/driver.c:249 usb_register_driver drivers/usb/core/driver.c:1078 [inline] usb_register_driver+0x21c/0x3e0 drivers/usb/core/driver.c:1060 do_one_initcall+0x11d/0x760 init/main.c:1382 do_initcall_level init/main.c:1444 [inline] do_initcalls init/main.c:1460 [inline] do_basic_setup init/main.c:1479 [inline] kernel_init_freeable+0x6e5/0x7a0 init/main.c:1692 kernel_init+0x1f/0x1e0 init/main.c:1582 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 page last free pid 24 tgid 24 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7e1/0x10d0 mm/page_alloc.c:2978 vfree.part.0+0x12b/0x9d0 mm/vmalloc.c:3479 vfree mm/vmalloc.c:3456 [inline] delayed_vfree_work+0x8e/0xd0 mm/vmalloc.c:3398 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3439 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff888028845b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888028845b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888028845c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888028845c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888028845d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================