Messages in this thread | | | From | Andrey Konovalov <> | Date | Mon, 23 Mar 2020 17:45:17 +0100 | Subject | Re: BUG: KASAN: use-after-free in usb_hcd_unlink_urb+0x5f/0x170 drivers/usb/core/hcd.c |
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On Mon, Mar 23, 2020 at 7:16 AM Kyungtae Kim <kt0755@gmail.com> wrote: > > We report a bug (in linux-5.5.11) found by FuzzUSB (a modified version > of syzkaller)
Hi Kyungtae,
Sounds interesting! Could you share what approach to USB fuzzing you have taken? Based on the stack trace I see you're fuzzing the USB storage layer, for which we don't yet have any descriptions in syzkaller's USB fuzzer itself [1].
Thanks!
[1] https://github.com/google/syzkaller/blob/master/docs/linux/external_fuzzing_usb.md
> > In function usb_hcd_unlink_urb (driver/usb/core/hcd.c:1607), it tries to > read "urb->use_count". But it seems the instance "urb" was > already freed (right after urb->dev at line 1597) by the function "urb_destroy" > in a different thread, which caused memory access violation. > To solve, it may need to check if urb is valid before urb->use_count, > to avoid such freed memory access. > > kernel config: https://kt0755.github.io/etc/config_v5.5.11 > > ================================================================== > BUG: KASAN: use-after-free in atomic_read > include/asm-generic/atomic-instrumented.h:26 [inline] > BUG: KASAN: use-after-free in usb_hcd_unlink_urb+0x5f/0x170 > drivers/usb/core/hcd.c:1607 > Read of size 4 at addr ffff888065379610 by task kworker/u4:1/27 > > CPU: 1 PID: 27 Comm: kworker/u4:1 Not tainted 5.5.11 #2 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > 1.10.2-1ubuntu1 04/01/2014 > Workqueue: scsi_tmf_2 scmd_eh_abort_handler > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0xce/0x128 lib/dump_stack.c:118 > print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374 > __kasan_report+0x153/0x1cb mm/kasan/report.c:506 > kasan_report+0x12/0x20 mm/kasan/common.c:639 > check_memory_region_inline mm/kasan/generic.c:185 [inline] > check_memory_region+0x152/0x1b0 mm/kasan/generic.c:192 > __kasan_check_read+0x11/0x20 mm/kasan/common.c:95 > atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] > usb_hcd_unlink_urb+0x5f/0x170 drivers/usb/core/hcd.c:1607 > usb_unlink_urb+0x72/0xb0 drivers/usb/core/urb.c:657 > usb_sg_cancel+0x14e/0x290 drivers/usb/core/message.c:602 > usb_stor_stop_transport+0x5e/0xa0 drivers/usb/storage/transport.c:937 > command_abort+0x19d/0x200 drivers/usb/storage/scsiglue.c:439 > scsi_try_to_abort_cmd drivers/scsi/scsi_error.c:927 [inline] > scmd_eh_abort_handler+0x18e/0x410 drivers/scsi/scsi_error.c:145 > process_one_work+0x9dd/0x1710 kernel/workqueue.c:2266 > worker_thread+0x8b/0xc40 kernel/workqueue.c:2412 > kthread+0x35f/0x440 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > Allocated by task 2532: > save_stack+0x21/0x90 mm/kasan/common.c:72 > set_track mm/kasan/common.c:80 [inline] > __kasan_kmalloc.constprop.3+0xa7/0xd0 mm/kasan/common.c:513 > kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527 > __kmalloc+0x148/0x380 mm/slub.c:3812 > kmalloc include/linux/slab.h:561 [inline] > usb_alloc_urb+0x42/0x90 drivers/usb/core/urb.c:74 > usb_sg_init+0x323/0xa00 drivers/usb/core/message.c:406 > usb_stor_bulk_transfer_sglist+0xbe/0x280 drivers/usb/storage/transport.c:423 > usb_stor_bulk_srb+0x10d/0x230 drivers/usb/storage/transport.c:465 > usb_stor_Bulk_transport+0x55f/0x1060 drivers/usb/storage/transport.c:1161 > usb_stor_invoke_transport+0xef/0x15f0 drivers/usb/storage/transport.c:606 > usb_stor_transparent_scsi_command+0x1d/0x30 drivers/usb/storage/protocol.c:108 > usb_stor_control_thread+0x6d8/0xa80 drivers/usb/storage/usb.c:380 > kthread+0x35f/0x440 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > Freed by task 2532: > save_stack+0x21/0x90 mm/kasan/common.c:72 > set_track mm/kasan/common.c:80 [inline] > kasan_set_free_info mm/kasan/common.c:335 [inline] > __kasan_slab_free+0x135/0x190 mm/kasan/common.c:474 > kasan_slab_free+0xe/0x10 mm/kasan/common.c:483 > slab_free_hook mm/slub.c:1425 [inline] > slab_free_freelist_hook mm/slub.c:1458 [inline] > slab_free mm/slub.c:3005 [inline] > kfree+0xf7/0x410 mm/slub.c:3966 > urb_destroy drivers/usb/core/urb.c:26 [inline] > kref_put include/linux/kref.h:65 [inline] > usb_free_urb.part.0+0x95/0x100 drivers/usb/core/urb.c:96 > usb_free_urb+0x1f/0x30 drivers/usb/core/urb.c:95 > sg_clean+0x111/0x270 drivers/usb/core/message.c:263 > usb_sg_wait+0x26d/0x440 drivers/usb/core/message.c:573 > usb_stor_bulk_transfer_sglist+0x127/0x280 drivers/usb/storage/transport.c:447 > usb_stor_bulk_srb+0x10d/0x230 drivers/usb/storage/transport.c:465 > usb_stor_Bulk_transport+0x55f/0x1060 drivers/usb/storage/transport.c:1161 > usb_stor_invoke_transport+0xef/0x15f0 drivers/usb/storage/transport.c:606 > usb_stor_transparent_scsi_command+0x1d/0x30 drivers/usb/storage/protocol.c:108 > usb_stor_control_thread+0x6d8/0xa80 drivers/usb/storage/usb.c:380 > kthread+0x35f/0x440 kernel/kthread.c:255 > ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 > > The buggy address belongs to the object at ffff888065379600 > which belongs to the cache kmalloc-192 of size 192 > The buggy address is located 16 bytes inside of > 192-byte region [ffff888065379600, ffff8880653796c0) > The buggy address belongs to the page: > page:ffffea000194de40 refcount:1 mapcount:0 mapping:ffff88806c002a00 index:0x0 > flags: 0x100000000000200(slab) > raw: 0100000000000200 ffffea0000ee7a00 0000000500000005 ffff88806c002a00 > raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff888065379500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ffff888065379580: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > >ffff888065379600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb > ^ > ffff888065379680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ffff888065379700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 > ================================================================== > > -- > You received this message because you are subscribed to the Google Groups "syzkaller" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller/CAEAjamtb2Kbn0He5O%2B%2B%3Dd_HCG1eQvLnGGbcVUOQ76%2BNfDiNybQ%40mail.gmail.com.
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