syzbot


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

Status: fixed on 2021/01/18 14:01
Reported-by: syzbot+fbbeeb520a74f5c346d1@syzkaller.appspotmail.com
Fix commit: 61490c481c61 Bluetooth: Fix slab-out-of-bounds read in hci_le_direct_adv_report_evt()
First crash: 852d, last: 711d

Fix bisection: fixed by (bisect log) :
commit 61490c481c61ff230da5f6042f353c6c0db0bc0c
Author: Peilin Ye <yepeilin.cs@gmail.com>
Date: Wed Sep 9 07:17:00 2020 +0000

  Bluetooth: Fix slab-out-of-bounds read in hci_le_direct_adv_report_evt()

similar bugs (4):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.14 KASAN: slab-out-of-bounds Read in hci_le_meta_evt C done 15 730d 850d 1/1 fixed on 2020/12/30 13:33
upstream KASAN: slab-out-of-bounds Read in hci_le_meta_evt (2) C inconclusive 2 395d 395d 22/24 fixed on 2022/03/08 16:11
linux-4.19 KASAN: slab-out-of-bounds Read in hci_le_meta_evt (2) C error 135 7d15h 565d 0/1 upstream: reported C repro on 2021/05/14 20:19
upstream KASAN: slab-out-of-bounds Read in hci_le_meta_evt C error error 45 728d 849d 21/24 fixed on 2021/03/10 01:49

Sample crash report:
Bluetooth: hci0: unknown advertising packet type: 0x4e
Bluetooth: hci0: unknown advertising packet type: 0x3d
Bluetooth: hci0: unknown advertising packet type: 0x41
Bluetooth: hci0: unknown advertising packet type: 0x3d
==================================================================
BUG: KASAN: slab-out-of-bounds in hci_le_direct_adv_report_evt net/bluetooth/hci_event.c:5619 [inline]
BUG: KASAN: slab-out-of-bounds in hci_le_meta_evt+0x33f5/0x3a50 net/bluetooth/hci_event.c:5660
Read of size 1 at addr ffff88808ba4228c by task kworker/u5:2/6453

CPU: 1 PID: 6453 Comm: kworker/u5:2 Not tainted 4.19.142-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+0x1fc/0x2fe lib/dump_stack.c:118
 print_address_description.cold+0x54/0x219 mm/kasan/report.c:256
 kasan_report_error.cold+0x8a/0x1c7 mm/kasan/report.c:354
 kasan_report mm/kasan/report.c:412 [inline]
 __asan_report_load1_noabort+0x88/0x90 mm/kasan/report.c:430
 hci_le_direct_adv_report_evt net/bluetooth/hci_event.c:5619 [inline]
 hci_le_meta_evt+0x33f5/0x3a50 net/bluetooth/hci_event.c:5660
 hci_event_packet+0x1e4a/0x862d net/bluetooth/hci_event.c:5904
 hci_rx_work+0x46b/0xa90 net/bluetooth/hci_core.c:4359
 process_one_work+0x864/0x1570 kernel/workqueue.c:2155
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2298
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415

Allocated by task 6446:
 __do_kmalloc_node mm/slab.c:3689 [inline]
 __kmalloc_node_track_caller+0x4c/0x70 mm/slab.c:3703
 __kmalloc_reserve net/core/skbuff.c:137 [inline]
 __alloc_skb+0xae/0x560 net/core/skbuff.c:205
 alloc_skb include/linux/skbuff.h:995 [inline]
 bt_skb_alloc include/net/bluetooth/bluetooth.h:339 [inline]
 vhci_get_user drivers/bluetooth/hci_vhci.c:180 [inline]
 vhci_write+0xbd/0x450 drivers/bluetooth/hci_vhci.c:299
 call_write_iter include/linux/fs.h:1821 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x51b/0x770 fs/read_write.c:487
 vfs_write+0x1f3/0x540 fs/read_write.c:549
 ksys_write+0x12b/0x2a0 fs/read_write.c:599
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 3715:
 __cache_free mm/slab.c:3503 [inline]
 kfree+0xcc/0x210 mm/slab.c:3822
 skb_free_head net/core/skbuff.c:554 [inline]
 skb_release_data+0x6de/0x920 net/core/skbuff.c:574
 skb_release_all net/core/skbuff.c:631 [inline]
 __kfree_skb net/core/skbuff.c:645 [inline]
 consume_skb+0x113/0x3d0 net/core/skbuff.c:705
 skb_free_datagram+0x16/0xf0 net/core/datagram.c:329
 netlink_recvmsg+0x627/0xea0 net/netlink/af_netlink.c:1988
 sock_recvmsg_nosec net/socket.c:795 [inline]
 sock_recvmsg net/socket.c:802 [inline]
 sock_recvmsg+0xca/0x110 net/socket.c:798
 ___sys_recvmsg+0x255/0x570 net/socket.c:2277
 __sys_recvmsg net/socket.c:2326 [inline]
 __do_sys_recvmsg net/socket.c:2336 [inline]
 __se_sys_recvmsg net/socket.c:2333 [inline]
 __x64_sys_recvmsg+0x12f/0x220 net/socket.c:2333
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88808ba42080
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 12 bytes to the right of
 512-byte region [ffff88808ba42080, ffff88808ba42280)
The buggy address belongs to the page:
page:ffffea00022e9080 count:1 mapcount:0 mapping:ffff88812c39c940 index:0xffff88808ba42d00
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffffea00022e6608 ffffea00022e9008 ffff88812c39c940
raw: ffff88808ba42d00 ffff88808ba42080 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808ba42180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88808ba42200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88808ba42280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff88808ba42300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808ba42380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (12):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci2-linux-4-19 2020/08/27 08:31 linux-4.19.y f6d5cb9e2c06 816e0689 .config log report syz C
ci2-linux-4-19 2020/08/03 10:37 linux-4.19.y 13af6c74b14a 96dd3623 .config log report syz C
ci2-linux-4-19 2020/08/03 10:17 linux-4.19.y 13af6c74b14a 96dd3623 .config log report syz C
ci2-linux-4-19 2020/08/03 01:04 linux-4.19.y 13af6c74b14a 96dd3623 .config log report syz C
ci2-linux-4-19 2020/07/31 09:56 linux-4.19.y 205a42ce2861 8df85ed9 .config log report syz C
ci2-linux-4-19 2020/12/19 08:15 linux-4.19.y 13d2ce42de8c 04201c06 .config log report info
ci2-linux-4-19 2020/08/14 05:22 linux-4.19.y c14d30dc9987 54ce1ed6 .config log report
ci2-linux-4-19 2020/08/07 16:05 linux-4.19.y 961f830af065 28ac5c9e .config log report
ci2-linux-4-19 2020/08/07 15:06 linux-4.19.y 961f830af065 28ac5c9e .config log report
ci2-linux-4-19 2020/08/02 12:30 linux-4.19.y 13af6c74b14a 96dd3623 .config log report
ci2-linux-4-19 2020/08/02 12:30 linux-4.19.y 13af6c74b14a 96dd3623 .config log report
ci2-linux-4-19 2020/08/02 11:19 linux-4.19.y 13af6c74b14a 96dd3623 .config log report
* Struck through repros no longer work on HEAD.