syzbot


KASAN: slab-use-after-free Read in pvr2_context_disconnect

Status: auto-obsoleted due to no activity on 2023/10/08 02:11
Subsystems: pvrusb2
[Documentation on labels]
Reported-by: syzbot+55d1fa0c2146c6aa29e2@syzkaller.appspotmail.com
First crash: 568d, last: 568d

Sample crash report:
pvrusb2: Device being rendered inoperable
pvrusb2: Device being rendered inoperable
==================================================================
BUG: KASAN: slab-use-after-free in pvr2_context_notify drivers/media/usb/pvrusb2/pvrusb2-context.c:95 [inline]
BUG: KASAN: slab-use-after-free in pvr2_context_disconnect+0x1c5/0x1f0 drivers/media/usb/pvrusb2/pvrusb2-context.c:271
Read of size 4 at addr ffff8880152c76d8 by task kworker/0:4/5079

CPU: 0 PID: 5079 Comm: kworker/0:4 Not tainted 6.4.0-syzkaller-12491-gc192ac735768 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Workqueue: usb_hub_wq hub_event
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e7/0x2d0 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:364 [inline]
 print_report+0x163/0x540 mm/kasan/report.c:475
 kasan_report+0x175/0x1b0 mm/kasan/report.c:588
 pvr2_context_notify drivers/media/usb/pvrusb2/pvrusb2-context.c:95 [inline]
 pvr2_context_disconnect+0x1c5/0x1f0 drivers/media/usb/pvrusb2/pvrusb2-context.c:271
 pvr_disconnect+0x78/0xe0 drivers/media/usb/pvrusb2/pvrusb2-main.c:79
 usb_unbind_interface+0x1d1/0x840 drivers/usb/core/driver.c:458
 device_remove drivers/base/dd.c:569 [inline]
 __device_release_driver drivers/base/dd.c:1270 [inline]
 device_release_driver_internal+0x4f9/0x7a0 drivers/base/dd.c:1293
 bus_remove_device+0x341/0x410 drivers/base/bus.c:574
 device_del+0x538/0x9c0 drivers/base/core.c:3814
 usb_disable_device+0x3bf/0x850 drivers/usb/core/message.c:1420
 usb_disconnect+0x340/0x8d0 drivers/usb/core/hub.c:2253
 hub_port_connect drivers/usb/core/hub.c:5261 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5566 [inline]
 port_event drivers/usb/core/hub.c:5726 [inline]
 hub_event+0x1f25/0x52c0 drivers/usb/core/hub.c:5808
 process_one_work+0x92c/0x12c0 kernel/workqueue.c:2597
 process_scheduled_works kernel/workqueue.c:2664 [inline]
 worker_thread+0xd20/0x1210 kernel/workqueue.c:2750
 kthread+0x2b8/0x350 kernel/kthread.c:389
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Allocated by task 5079:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4f/0x70 mm/kasan/common.c:52
 ____kasan_kmalloc mm/kasan/common.c:374 [inline]
 __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:383
 kmalloc include/linux/slab.h:582 [inline]
 kzalloc include/linux/slab.h:703 [inline]
 pvr2_context_create+0x5b/0x370 drivers/media/usb/pvrusb2/pvrusb2-context.c:207
 pvr_probe+0x26/0xd0 drivers/media/usb/pvrusb2/pvrusb2-main.c:54
 usb_probe_interface+0x5c4/0xb00 drivers/usb/core/driver.c:396
 really_probe+0x294/0xc30 drivers/base/dd.c:658
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:798
 driver_probe_device+0x50/0x420 drivers/base/dd.c:828
 __device_attach_driver+0x2d3/0x520 drivers/base/dd.c:956
 bus_for_each_drv+0x24a/0x2d0 drivers/base/bus.c:457
 __device_attach+0x32f/0x510 drivers/base/dd.c:1028
 bus_probe_device+0x185/0x260 drivers/base/bus.c:532
 device_add+0xb75/0xf60 drivers/base/core.c:3625
 usb_set_configuration+0x1976/0x1fb0 drivers/usb/core/message.c:2211
 usb_generic_driver_probe+0x88/0x140 drivers/usb/core/generic.c:238
 usb_probe_device+0x134/0x270 drivers/usb/core/driver.c:293
 really_probe+0x294/0xc30 drivers/base/dd.c:658
 __driver_probe_device+0x1a2/0x3d0 drivers/base/dd.c:798
 driver_probe_device+0x50/0x420 drivers/base/dd.c:828
 __device_attach_driver+0x2d3/0x520 drivers/base/dd.c:956
 bus_for_each_drv+0x24a/0x2d0 drivers/base/bus.c:457
 __device_attach+0x32f/0x510 drivers/base/dd.c:1028
 bus_probe_device+0x185/0x260 drivers/base/bus.c:532
 device_add+0xb75/0xf60 drivers/base/core.c:3625
 usb_new_device+0xb7e/0x18d0 drivers/usb/core/hub.c:2590
 hub_port_connect drivers/usb/core/hub.c:5422 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5566 [inline]
 port_event drivers/usb/core/hub.c:5726 [inline]
 hub_event+0x2e9e/0x52c0 drivers/usb/core/hub.c:5808
 process_one_work+0x92c/0x12c0 kernel/workqueue.c:2597
 process_scheduled_works kernel/workqueue.c:2664 [inline]
 worker_thread+0xd20/0x1210 kernel/workqueue.c:2750
 kthread+0x2b8/0x350 kernel/kthread.c:389
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

Freed by task 1955:
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4f/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:162 [inline]
 slab_free_hook mm/slub.c:1792 [inline]
 slab_free_freelist_hook mm/slub.c:1818 [inline]
 slab_free mm/slub.c:3801 [inline]
 __kmem_cache_free+0x25f/0x3b0 mm/slub.c:3814
 pvr2_context_check drivers/media/usb/pvrusb2/pvrusb2-context.c:137 [inline]
 pvr2_context_thread_func+0x401/0xb40 drivers/media/usb/pvrusb2/pvrusb2-context.c:158
 kthread+0x2b8/0x350 kernel/kthread.c:389
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

The buggy address belongs to the object at ffff8880152c7600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 216 bytes inside of
 freed 256-byte region [ffff8880152c7600, ffff8880152c7700)

The buggy address belongs to the physical page:
page:ffffea000054b180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x152c6
head:ffffea000054b180 order:1 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xffffffff()
raw: 00fff00000010200 ffff888012841b40 ffffea0000a41c00 dead000000000002
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0x1d2040(__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5233, tgid 5233 (udevd), ts 2502895348083, free_ts 2474659527550
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x1e6/0x210 mm/page_alloc.c:1570
 prep_new_page mm/page_alloc.c:1577 [inline]
 get_page_from_freelist+0x31e8/0x3370 mm/page_alloc.c:3221
 __alloc_pages+0x255/0x670 mm/page_alloc.c:4477
 alloc_slab_page+0x6a/0x160 mm/slub.c:1862
 allocate_slab mm/slub.c:2009 [inline]
 new_slab+0x84/0x2f0 mm/slub.c:2062
 ___slab_alloc+0xade/0x1100 mm/slub.c:3215
 __slab_alloc mm/slub.c:3314 [inline]
 __slab_alloc_node mm/slub.c:3367 [inline]
 slab_alloc_node mm/slub.c:3460 [inline]
 __kmem_cache_alloc_node+0x1af/0x270 mm/slub.c:3509
 kmalloc_trace+0x2a/0xe0 mm/slab_common.c:1076
 kmalloc include/linux/slab.h:582 [inline]
 kzalloc include/linux/slab.h:703 [inline]
 smk_fetch+0x92/0x140 security/smack/smack_lsm.c:291
 smack_d_instantiate+0x6d9/0xb40 security/smack/smack_lsm.c:3504
 security_d_instantiate+0x9b/0xf0 security/security.c:3760
 d_instantiate+0x55/0x90 fs/dcache.c:2034
 shmem_mknod+0x17d/0x1c0 mm/shmem.c:3089
 lookup_open fs/namei.c:3492 [inline]
 open_last_lookups fs/namei.c:3560 [inline]
 path_openat+0x13e7/0x3180 fs/namei.c:3790
 do_filp_open+0x234/0x490 fs/namei.c:3820
 do_sys_openat2+0x13e/0x1d0 fs/open.c:1407
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1161 [inline]
 free_unref_page_prepare+0x903/0xa30 mm/page_alloc.c:2348
 free_unref_page+0x37/0x3f0 mm/page_alloc.c:2443
 __slab_free+0x2f6/0x390 mm/slub.c:3707
 qlist_free_all+0x22/0x60 mm/kasan/quarantine.c:185
 kasan_quarantine_reduce+0x14b/0x160 mm/kasan/quarantine.c:292
 __kasan_slab_alloc+0x23/0x70 mm/kasan/common.c:305
 kasan_slab_alloc include/linux/kasan.h:186 [inline]
 slab_post_alloc_hook+0x6c/0x3b0 mm/slab.h:762
 slab_alloc_node mm/slub.c:3470 [inline]
 slab_alloc mm/slub.c:3478 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3485 [inline]
 kmem_cache_alloc+0x123/0x300 mm/slub.c:3494
 getname_flags+0xbc/0x4e0 fs/namei.c:140
 vfs_fstatat fs/stat.c:275 [inline]
 __do_sys_newfstatat fs/stat.c:446 [inline]
 __se_sys_newfstatat fs/stat.c:440 [inline]
 __x64_sys_newfstatat+0x12e/0x1d0 fs/stat.c:440
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff8880152c7580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880152c7600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880152c7680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
 ffff8880152c7700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880152c7780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/07/10 02:11 upstream c192ac735768 668cb1fa .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root KASAN: slab-use-after-free Read in pvr2_context_disconnect
* Struck through repros no longer work on HEAD.