Hello, syzbot found the following issue on: HEAD commit: 6342649c33d2 Merge tag 'block-6.11-20240726' of git://git... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=159feda1980000 kernel config: https://syzkaller.appspot.com/x/.config?x=5efb917b1462a973 dashboard link: https://syzkaller.appspot.com/bug?extid=16062f26c6480975e5ed compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40 userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/f7155d1516ca/disk-6342649c.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/f724a979b927/vmlinux-6342649c.xz kernel image: https://storage.googleapis.com/syzbot-assets/480121fc37f0/bzImage-6342649c.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+16062f26c6480975e5ed@xxxxxxxxxxxxxxxxxxxxxxxxx em28xx 5-1:0.0: Closing input extension ================================================================== BUG: KASAN: slab-use-after-free in media_device_unregister+0x154/0x470 Read of size 8 at addr ffff888058df4210 by task kworker/0:1/9 CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.10.0-syzkaller-12881-g6342649c33d2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 Workqueue: usb_hub_wq hub_event Call Trace: <TASK> __dump_stack lib/dump_stack.c:93 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:119 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 media_device_unregister+0x154/0x470 em28xx_unregister_media_device drivers/media/usb/em28xx/em28xx-cards.c:3511 [inline] em28xx_release_resources+0xa7/0x230 drivers/media/usb/em28xx/em28xx-cards.c:3532 em28xx_usb_disconnect+0x1cc/0x530 drivers/media/usb/em28xx/em28xx-cards.c:4201 usb_unbind_interface+0x25e/0x940 drivers/usb/core/driver.c:461 device_remove drivers/base/dd.c:568 [inline] __device_release_driver drivers/base/dd.c:1272 [inline] device_release_driver_internal+0x503/0x7c0 drivers/base/dd.c:1295 bus_remove_device+0x34f/0x420 drivers/base/bus.c:574 device_del+0x57a/0x9b0 drivers/base/core.c:3868 usb_disable_device+0x3bf/0x850 drivers/usb/core/message.c:1418 usb_disconnect+0x340/0x950 drivers/usb/core/hub.c:2304 hub_port_connect drivers/usb/core/hub.c:5361 [inline] hub_port_connect_change drivers/usb/core/hub.c:5661 [inline] port_event drivers/usb/core/hub.c:5821 [inline] hub_event+0x1eb9/0x5150 drivers/usb/core/hub.c:5903 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 </TASK> Allocated by task 31851: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:370 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387 kasan_kmalloc include/linux/kasan.h:211 [inline] __kmalloc_cache_noprof+0x19c/0x2c0 mm/slub.c:4189 kmalloc_noprof include/linux/slab.h:681 [inline] kzalloc_noprof include/linux/slab.h:807 [inline] em28xx_v4l2_init+0xfd/0x2f40 drivers/media/usb/em28xx/em28xx-video.c:2534 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Freed by task 31851: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:579 poison_slab_object+0xe0/0x150 mm/kasan/common.c:240 __kasan_slab_free+0x37/0x60 mm/kasan/common.c:256 kasan_slab_free include/linux/kasan.h:184 [inline] slab_free_hook mm/slub.c:2252 [inline] slab_free mm/slub.c:4473 [inline] kfree+0x149/0x360 mm/slub.c:4594 em28xx_free_v4l2 drivers/media/usb/em28xx/em28xx-video.c:2120 [inline] kref_put include/linux/kref.h:65 [inline] em28xx_v4l2_init+0x16d7/0x2f40 drivers/media/usb/em28xx/em28xx-video.c:2903 em28xx_init_extension+0x120/0x1c0 drivers/media/usb/em28xx/em28xx-core.c:1117 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff888058df4000 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 528 bytes inside of freed 8192-byte region [ffff888058df4000, ffff888058df6000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58df0 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xfdffffff(slab) raw: 00fff00000000040 ffff888015842280 dead000000000122 0000000000000000 raw: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000 head: 00fff00000000040 ffff888015842280 dead000000000122 0000000000000000 head: 0000000000000000 0000000080020002 00000001fdffffff 0000000000000000 head: 00fff00000000003 ffffea0001637c01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x152820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_HARDWALL), pid 3922, tgid 3922 (kworker/u8:8), ts 2368883364470, free_ts 2368880799693 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493 prep_new_page mm/page_alloc.c:1501 [inline] get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3442 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4700 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline] alloc_pages_node_noprof include/linux/gfp.h:296 [inline] alloc_slab_page+0x5f/0x120 mm/slub.c:2321 allocate_slab+0x5a/0x2f0 mm/slub.c:2484 new_slab mm/slub.c:2537 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3723 __slab_alloc+0x58/0xa0 mm/slub.c:3813 __slab_alloc_node mm/slub.c:3866 [inline] slab_alloc_node mm/slub.c:4025 [inline] __do_kmalloc_node mm/slub.c:4157 [inline] __kmalloc_noprof+0x25a/0x400 mm/slub.c:4170 kmalloc_noprof include/linux/slab.h:685 [inline] n_hdlc_tty_receive+0x1ce/0x4e0 drivers/tty/n_hdlc.c:393 tty_ldisc_receive_buf+0x11f/0x170 drivers/tty/tty_buffer.c:391 tty_port_default_receive_buf+0x6d/0xa0 drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:445 [inline] flush_to_ldisc+0x328/0x860 drivers/tty/tty_buffer.c:495 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 page last free pid 13102 tgid 13102 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1094 [inline] free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612 discard_slab mm/slub.c:2583 [inline] __put_partials+0xeb/0x130 mm/slub.c:3051 put_cpu_partial+0x17c/0x250 mm/slub.c:3126 __slab_free+0x2ea/0x3d0 mm/slub.c:4343 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322 kasan_slab_alloc include/linux/kasan.h:201 [inline] slab_post_alloc_hook mm/slub.c:3988 [inline] slab_alloc_node mm/slub.c:4037 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4044 anon_vma_chain_alloc mm/rmap.c:142 [inline] __anon_vma_prepare+0xc4/0x4a0 mm/rmap.c:195 vmf_anon_prepare mm/memory.c:3289 [inline] do_anonymous_page mm/memory.c:4551 [inline] do_pte_missing mm/memory.c:3945 [inline] handle_pte_fault+0x5788/0x6eb0 mm/memory.c:5522 __handle_mm_fault mm/memory.c:5665 [inline] handle_mm_fault+0x1029/0x1980 mm/memory.c:5833 do_user_addr_fault arch/x86/mm/fault.c:1338 [inline] handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x459/0x8c0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 Memory state around the buggy address: ffff888058df4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888058df4180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888058df4200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888058df4280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888058df4300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup
