================================================================== BUG: KASAN: slab-use-after-free in dev_name include/linux/device.h:934 [inline] BUG: KASAN: slab-use-after-free in __dynamic_dev_dbg+0x2fc/0x310 lib/dynamic_debug.c:904 Read of size 8 at addr ffff888073d6a120 by task syz.3.2432/17298 CPU: 2 UID: 0 PID: 17298 Comm: syz.3.2432 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 dev_name include/linux/device.h:934 [inline] __dynamic_dev_dbg+0x2fc/0x310 lib/dynamic_debug.c:904 vga_arb_release+0x3e7/0x540 drivers/pci/vgaarb.c:1434 __fput+0x3ff/0xb50 fs/file_table.c:512 task_work_run+0x150/0x240 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1d8/0x700 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline] __do_fast_syscall_32+0x59f/0x8b0 arch/x86/entry/syscall_32.c:294 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7f37fec Code: Unable to access opcode bytes at 0xf7f37fc2. RSP: 002b:00000000ff9fe05c EFLAGS: 00000202 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 000000000000001e RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 12725: 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 kasan_kmalloc include/linux/kasan.h:263 [inline] __kmalloc_cache_noprof+0x2f8/0x6d0 mm/slub.c:5563 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] pci_alloc_dev+0x47/0x270 drivers/pci/probe.c:2504 pci_scan_device drivers/pci/probe.c:2605 [inline] pci_scan_single_device drivers/pci/probe.c:2790 [inline] pci_scan_single_device+0x10c/0x240 drivers/pci/probe.c:2780 pci_scan_slot+0x1c9/0x7c0 drivers/pci/probe.c:2877 pci_scan_child_bus_extend+0x6b/0x7b0 drivers/pci/probe.c:3096 pci_scan_child_bus drivers/pci/probe.c:3209 [inline] pci_rescan_bus+0x18/0x40 drivers/pci/probe.c:3500 rescan_store+0xfb/0x130 drivers/pci/pci-sysfs.c:474 bus_attr_store+0x74/0xb0 drivers/base/bus.c:172 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6af/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 17302: 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:2748 [inline] slab_free mm/slub.c:6499 [inline] kfree+0x22b/0x6d0 mm/slub.c:6792 device_release+0xd2/0x270 drivers/base/core.c:2640 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x1f7/0x640 lib/kobject.c:737 put_device+0x1f/0x30 drivers/base/core.c:3884 pci_destroy_dev drivers/pci/remove.c:58 [inline] pci_remove_bus_device+0x305/0x3b0 drivers/pci/remove.c:111 pci_stop_and_remove_bus_device_locked+0x1a/0x20 drivers/pci/remove.c:137 remove_store+0x123/0x140 drivers/pci/pci-sysfs.c:524 dev_attr_store+0x58/0x80 drivers/base/core.c:2509 sysfs_kf_write+0xf2/0x150 fs/sysfs/file.c:145 kernfs_fop_write_iter+0x3e0/0x5f0 fs/kernfs/file.c:345 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x6af/0x1050 fs/read_write.c:687 ksys_write+0x12a/0x250 fs/read_write.c:739 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x13a/0x8b0 arch/x86/entry/syscall_32.c:291 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:316 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888073d6a000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 288 bytes inside of freed 4096-byte region [ffff888073d6a000, ffff888073d6b000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x73d68 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801c043040 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff88801c043040 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 04fff00000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5150, tgid 5150 (udevd), ts 160487930842 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+0x2eb/0x3300 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:7410 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+0x67c/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827 security_inode_getattr+0x116/0x280 security/security.c:1895 vfs_getattr fs/stat.c:259 [inline] vfs_fstat+0x4b/0xe0 fs/stat.c:281 __do_sys_newfstat+0x8b/0x110 fs/stat.c:551 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x121/0x770 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5150 tgid 5150 ts 160232072250 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1418 [inline] __free_frozen_pages+0x79f/0x10f0 mm/page_alloc.c:2962 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4683 [inline] slab_alloc_node mm/slub.c:4996 [inline] __do_kmalloc_node mm/slub.c:5413 [inline] __kmalloc_noprof+0x2cc/0x840 mm/slub.c:5439 _kmalloc_noprof include/linux/slab.h:995 [inline] tomoyo_realpath_from_path+0xb6/0x690 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827 security_inode_getattr+0x116/0x280 security/security.c:1895 vfs_getattr fs/stat.c:259 [inline] vfs_fstat+0x4b/0xe0 fs/stat.c:281 __do_sys_newfstat+0x8b/0x110 fs/stat.c:551 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x121/0x770 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888073d6a000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888073d6a080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888073d6a100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888073d6a180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888073d6a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================