syzbot

 sign-in | mailing list | source | docs
🐞 Open [987] ≡ Subsystems 🐞 Fixed [5236] 🐞 Invalid [12507] ⬇ Missing Backports [83] 📈 Kernel Health 📈 Bug Lifetimes 📈 Fuzzing 📈 Crashes 💬 Send us feedback

KASAN: use-after-free Read in prepare_to_wait_event

Status: closed as dup on 2019/08/12 12:05
Subsystems: usb
[Documentation on labels]
Reported-by: syzbot+332cbcbd8be3e03c62eb@syzkaller.appspotmail.com
First crash: 1721d, last: 1715d
▶ ▼ Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
KASAN: use-after-free Read in ld_usb_release usb C 14 1711d 1721d
▶ ▼ Discussions (1)
Title Replies (including bot) Last reply
KASAN: use-after-free Read in prepare_to_wait_event 1 (2) 2019/08/12 12:05
▶ ▼ Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in prepare_to_wait_event (2) rdma 1 1376d 1372d 0/26 auto-closed as invalid on 2020/10/17 06:03

Sample crash report:
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x302a/0x3b50 kernel/locking/lockdep.c:3753
Read of size 8 at addr ffff8881d2a83238 by task syz-executor771/2979

CPU: 0 PID: 2979 Comm: syz-executor771 Not tainted 5.3.0-rc2+ #25
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xca/0x13e lib/dump_stack.c:113
 print_address_description+0x6a/0x32c mm/kasan/report.c:351
 __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
 kasan_report+0xe/0x12 mm/kasan/common.c:612
 __lock_acquire+0x302a/0x3b50 kernel/locking/lockdep.c:3753
 lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4412
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x32/0x50 kernel/locking/spinlock.c:159
 prepare_to_wait_event+0x5b/0x650 kernel/sched/wait.c:263
 ld_usb_read+0x619/0x780 drivers/usb/misc/ldusb.c:480
 __vfs_read+0x76/0x100 fs/read_write.c:425
 vfs_read+0x1ea/0x430 fs/read_write.c:461
 ksys_read+0x1e8/0x250 fs/read_write.c:587
 do_syscall_64+0xb7/0x580 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x448859
Code: e8 ac e7 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 4b 06 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f9b31740ce8 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00000000006dec48 RCX: 0000000000448859
RDX: 0000000000000049 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 00000000006dec40 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dec4c
R13: 00007ffd58e161df R14: 00007f9b317419c0 R15: 00000000006dec4c

Allocated by task 2705:
 save_stack+0x1b/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:487 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:460
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:748 [inline]
 ld_usb_probe+0x6e/0xa65 drivers/usb/misc/ldusb.c:661
 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
 really_probe+0x281/0x650 drivers/base/dd.c:548
 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
 __device_attach+0x217/0x360 drivers/base/dd.c:882
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
 device_add+0xae6/0x16f0 drivers/base/core.c:2114
 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
 really_probe+0x281/0x650 drivers/base/dd.c:548
 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
 __device_attach+0x217/0x360 drivers/base/dd.c:882
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
 device_add+0xae6/0x16f0 drivers/base/core.c:2114
 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
 hub_port_connect drivers/usb/core/hub.c:5098 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
 port_event drivers/usb/core/hub.c:5359 [inline]
 hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
 worker_thread+0x96/0xe20 kernel/workqueue.c:2415
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

Freed by task 2705:
 save_stack+0x1b/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x130/0x180 mm/kasan/common.c:449
 slab_free_hook mm/slub.c:1423 [inline]
 slab_free_freelist_hook mm/slub.c:1470 [inline]
 slab_free mm/slub.c:3012 [inline]
 kfree+0xe4/0x2f0 mm/slub.c:3953
 ld_usb_probe+0x728/0xa65 drivers/usb/misc/ldusb.c:744
 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
 really_probe+0x281/0x650 drivers/base/dd.c:548
 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
 __device_attach+0x217/0x360 drivers/base/dd.c:882
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
 device_add+0xae6/0x16f0 drivers/base/core.c:2114
 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
 really_probe+0x281/0x650 drivers/base/dd.c:548
 driver_probe_device+0x101/0x1b0 drivers/base/dd.c:709
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:816
 bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
 __device_attach+0x217/0x360 drivers/base/dd.c:882
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
 device_add+0xae6/0x16f0 drivers/base/core.c:2114
 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2536
 hub_port_connect drivers/usb/core/hub.c:5098 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
 port_event drivers/usb/core/hub.c:5359 [inline]
 hub_event+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
 worker_thread+0x96/0xe20 kernel/workqueue.c:2415
 kthread+0x318/0x420 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8881d2a83180
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 184 bytes inside of
 512-byte region [ffff8881d2a83180, ffff8881d2a83380)
The buggy address belongs to the page:
page:ffffea00074aa080 refcount:1 mapcount:0 mapping:ffff8881da002500 index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da002500
raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881d2a83100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8881d2a83180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881d2a83200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff8881d2a83280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d2a83300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/08/09 05:30 https://github.com/google/kasan.git usb-fuzzer e96407b49762 ede31a9b .config console log report syz C ci2-upstream-usb
2019/08/15 02:46 https://github.com/google/kasan.git usb-fuzzer d0847550e22d 0d298d6b .config console log report ci2-upstream-usb
* Struck through repros no longer work on HEAD.