syzbot


KASAN: slab-out-of-bounds Read in hci_inquiry_result_with_rssi_evt

Status: fixed on 2020/09/16 22:51
Subsystems: bluetooth
[Documentation on labels]
Reported-by: syzbot+3a430af182785b4c7360@syzkaller.appspotmail.com
Fix commit: 629b49c848ee Bluetooth: Prevent out-of-bounds read in hci_inquiry_result_with_rssi_evt()
First crash: 1441d, last: 1417d
Cause bisection: failed (error log, bisect log)
  
Discussions (1)
Title Replies (including bot) Last reply
KASAN: slab-out-of-bounds Read in hci_inquiry_result_with_rssi_evt 0 (1) 2020/07/13 19:24
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 KASAN: slab-out-of-bounds Read in hci_inquiry_result_with_rssi_evt C done 6 1402d 1419d 1/1 fixed on 2020/09/16 13:17
linux-4.19 KASAN: slab-out-of-bounds Read in hci_inquiry_result_with_rssi_evt C done 4 1412d 1441d 1/1 fixed on 2020/09/09 05:22

Sample crash report:
==================================================================
BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:406 [inline]
BUG: KASAN: slab-out-of-bounds in bacpy include/net/bluetooth/bluetooth.h:274 [inline]
BUG: KASAN: slab-out-of-bounds in hci_inquiry_result_with_rssi_evt+0x230/0x6b0 net/bluetooth/hci_event.c:4172
Read of size 6 at addr ffff8880a75af9fb by task kworker/u5:1/6846

CPU: 1 PID: 6846 Comm: kworker/u5:1 Not tainted 5.8.0-rc7-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: hci0 hci_rx_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x436 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x13d/0x180 mm/kasan/generic.c:192
 memcpy+0x20/0x60 mm/kasan/common.c:105
 memcpy include/linux/string.h:406 [inline]
 bacpy include/net/bluetooth/bluetooth.h:274 [inline]
 hci_inquiry_result_with_rssi_evt+0x230/0x6b0 net/bluetooth/hci_event.c:4172
 hci_event_packet+0x1e8c/0x86f5 net/bluetooth/hci_event.c:6115
 hci_rx_work+0x22e/0xb10 net/bluetooth/hci_core.c:4705
 process_one_work+0x94c/0x1670 kernel/workqueue.c:2269
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293

Allocated by task 6822:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc2/0xd0 mm/kasan/common.c:494
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0xae/0x550 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1083 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:377 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:165 [inline]
 vhci_write+0xbd/0x450 drivers/bluetooth/hci_vhci.c:285
 call_write_iter include/linux/fs.h:1908 [inline]
 new_sync_write+0x422/0x650 fs/read_write.c:503
 vfs_write+0x59d/0x6b0 fs/read_write.c:578
 ksys_write+0x12d/0x250 fs/read_write.c:631
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 4774:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0xf5/0x140 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x103/0x2c0 mm/slab.c:3757
 kernfs_fop_release+0x120/0x190 fs/kernfs/file.c:782
 __fput+0x33c/0x880 fs/file_table.c:281
 task_work_run+0xdd/0x190 kernel/task_work.c:135
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop arch/x86/entry/common.c:239 [inline]
 __prepare_exit_to_usermode+0x1e9/0x1f0 arch/x86/entry/common.c:269
 do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:393
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880a75af800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 507 bytes inside of
 512-byte region [ffff8880a75af800, ffff8880a75afa00)
The buggy address belongs to the page:
page:ffffea00029d6bc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea000289e8c8 ffffea00024c0cc8 ffff8880aa000a80
raw: 0000000000000000 ffff8880a75af000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880a75af900: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880a75af980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880a75afa00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff8880a75afa80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880a75afb00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2020/08/02 22:57 upstream ac3a0c847296 63a73341 .config console log report syz C ci-upstream-kasan-gce-root
2020/08/01 07:10 upstream d8b9faec54ae d895b3be .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/07/11 00:29 upstream a581387e415b 18d18b59 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2020/07/09 23:33 upstream 0bddd227f3dc bc238812 .config console log report syz C ci-upstream-kasan-gce-root
2020/07/09 19:27 upstream 0bddd227f3dc bc238812 .config console log report syz C ci-upstream-kasan-gce
2020/07/09 19:56 upstream 0bddd227f3dc bc238812 .config console log report syz C ci-upstream-kasan-gce-386
2020/07/11 20:04 linux-next d31958b30ea3 18d18b59 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2020/08/02 10:39 upstream ac3a0c847296 63a73341 .config console log report ci-upstream-kasan-gce-selinux-root
2020/07/09 19:14 upstream 0bddd227f3dc bc238812 .config console log report ci-upstream-kasan-gce
* Struck through repros no longer work on HEAD.