syzbot


KMSAN: kernel-infoleak in wdm_read

Status: upstream: reported on 2024/08/20 22:48
Subsystems: usb
[Documentation on labels]
Reported-by: syzbot+9760fbbd535cee131f81@syzkaller.appspotmail.com
First crash: 59d, last: 59d
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [usb?] KMSAN: kernel-infoleak in wdm_read 0 (1) 2024/08/20 22:48

Sample crash report:
=====================================================
BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in _inline_copy_to_user include/linux/uaccess.h:180 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x110 lib/usercopy.c:26
 instrument_copy_to_user include/linux/instrumented.h:114 [inline]
 _inline_copy_to_user include/linux/uaccess.h:180 [inline]
 _copy_to_user+0xbc/0x110 lib/usercopy.c:26
 copy_to_user include/linux/uaccess.h:209 [inline]
 wdm_read+0x227/0x1270 drivers/usb/class/cdc-wdm.c:603
 vfs_read+0x2a1/0xf60 fs/read_write.c:474
 ksys_read+0x20f/0x4c0 fs/read_write.c:619
 __do_sys_read fs/read_write.c:629 [inline]
 __se_sys_read fs/read_write.c:627 [inline]
 __x64_sys_read+0x93/0xe0 fs/read_write.c:627
 x64_sys_call+0x3055/0x3ba0 arch/x86/include/generated/asm/syscalls_64.h:1
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:3994 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 __do_kmalloc_node mm/slub.c:4157 [inline]
 __kmalloc_noprof+0x661/0xf30 mm/slub.c:4170
 kmalloc_noprof include/linux/slab.h:685 [inline]
 wdm_create+0xf5a/0x2240 drivers/usb/class/cdc-wdm.c:1066
 wdm_probe+0x265/0x330 drivers/usb/class/cdc-wdm.c:1165
 usb_probe_interface+0xd6f/0x1350 drivers/usb/core/driver.c:399
 really_probe+0x4db/0xd90 drivers/base/dd.c:657
 __driver_probe_device+0x2ab/0x5d0 drivers/base/dd.c:799
 driver_probe_device+0x72/0x890 drivers/base/dd.c:829
 __device_attach_driver+0x568/0x9e0 drivers/base/dd.c:957
 bus_for_each_drv+0x403/0x620 drivers/base/bus.c:457
 __device_attach+0x3c1/0x650 drivers/base/dd.c:1029
 device_initial_probe+0x32/0x40 drivers/base/dd.c:1078
 bus_probe_device+0x3dc/0x5c0 drivers/base/bus.c:532
 device_add+0x13aa/0x1ba0 drivers/base/core.c:3682
 usb_set_configuration+0x31c9/0x38d0 drivers/usb/core/message.c:2210
 usb_generic_driver_probe+0x109/0x2a0 drivers/usb/core/generic.c:254
 usb_probe_device+0x3a7/0x690 drivers/usb/core/driver.c:294
 really_probe+0x4db/0xd90 drivers/base/dd.c:657
 __driver_probe_device+0x2ab/0x5d0 drivers/base/dd.c:799
 driver_probe_device+0x72/0x890 drivers/base/dd.c:829
 __device_attach_driver+0x568/0x9e0 drivers/base/dd.c:957
 bus_for_each_drv+0x403/0x620 drivers/base/bus.c:457
 __device_attach+0x3c1/0x650 drivers/base/dd.c:1029
 device_initial_probe+0x32/0x40 drivers/base/dd.c:1078
 bus_probe_device+0x3dc/0x5c0 drivers/base/bus.c:532
 device_add+0x13aa/0x1ba0 drivers/base/core.c:3682
 usb_new_device+0x15f4/0x2470 drivers/usb/core/hub.c:2651
 hub_port_connect drivers/usb/core/hub.c:5521 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x4ffb/0x72d0 drivers/usb/core/hub.c:5903
 process_one_work kernel/workqueue.c:3231 [inline]
 process_scheduled_works+0xae0/0x1c40 kernel/workqueue.c:3312
 worker_thread+0xea5/0x1520 kernel/workqueue.c:3390
 kthread+0x3dd/0x540 kernel/kthread.c:389
 ret_from_fork+0x6d/0x90 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244

Byte 0 of 1 is uninitialized
Memory access of size 1 starts at ffff88803f011400
Data copied to user address 0000000020000280

CPU: 1 UID: 0 PID: 7440 Comm: syz.1.721 Not tainted 6.11.0-rc3-syzkaller-00156-gd7a5aa4b3c00 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024
=====================================================

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/08/16 22:41 upstream d7a5aa4b3c00 76120936 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kmsan-gce-root KMSAN: kernel-infoleak in wdm_read
* Struck through repros no longer work on HEAD.