Hello, syzbot found the following issue on: HEAD commit: ce8056d1 wip: changed copy_from_user where instrumented git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=124d453c900000 kernel config: https://syzkaller.appspot.com/x/.config?x=3afe005fb99591f dashboard link: https://syzkaller.appspot.com/bug?extid=f83a1df1ed4f67e8d8ad compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) userspace arch: i386 Unfortunately, I don't have any reproducer for this issue yet. IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+f83a1df1ed4f67e8d8ad@xxxxxxxxxxxxxxxxxxxxxxxxx usb 4-1: ath9k_htc: Transferred FW: ath9k_htc/htc_9271-1.4.0.fw, size: 51008 ===================================================== BUG: KMSAN: kernel-usb-infoleak in kmsan_handle_urb+0x28/0x40 mm/kmsan/kmsan_hooks.c:307 CPU: 1 PID: 13012 Comm: kworker/1:6 Not tainted 5.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events request_firmware_work_func Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 kmsan_internal_check_memory+0x238/0x3d0 mm/kmsan/kmsan.c:423 kmsan_handle_urb+0x28/0x40 mm/kmsan/kmsan_hooks.c:307 usb_submit_urb+0x861/0x2470 drivers/usb/core/urb.c:406 hif_usb_send_regout drivers/net/wireless/ath/ath9k/hif_usb.c:127 [inline] hif_usb_send+0x633/0x1790 drivers/net/wireless/ath/ath9k/hif_usb.c:470 htc_issue_send drivers/net/wireless/ath/ath9k/htc_hst.c:34 [inline] htc_connect_service+0x14b4/0x19f0 drivers/net/wireless/ath/ath9k/htc_hst.c:275 ath9k_wmi_connect+0x178/0x2c0 drivers/net/wireless/ath/ath9k/wmi.c:268 ath9k_init_htc_services+0xf3/0x11f0 drivers/net/wireless/ath/ath9k/htc_drv_init.c:146 ath9k_htc_probe_device+0x4dc/0x3ed0 drivers/net/wireless/ath/ath9k/htc_drv_init.c:962 ath9k_htc_hw_init+0xdf/0x190 drivers/net/wireless/ath/ath9k/htc_hst.c:501 ath9k_hif_usb_firmware_cb+0x42e/0xab0 drivers/net/wireless/ath/ath9k/hif_usb.c:1218 request_firmware_work_func+0x1aa/0x2d0 drivers/base/firmware_loader/main.c:1001 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 kthread+0x551/0x590 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80 slab_alloc_node mm/slub.c:2839 [inline] __kmalloc_node_track_caller+0xeab/0x12e0 mm/slub.c:4478 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0x35f/0xb30 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] htc_connect_service+0x1057/0x19f0 drivers/net/wireless/ath/ath9k/htc_hst.c:258 ath9k_wmi_connect+0x178/0x2c0 drivers/net/wireless/ath/ath9k/wmi.c:268 ath9k_init_htc_services+0xf3/0x11f0 drivers/net/wireless/ath/ath9k/htc_drv_init.c:146 ath9k_htc_probe_device+0x4dc/0x3ed0 drivers/net/wireless/ath/ath9k/htc_drv_init.c:962 ath9k_htc_hw_init+0xdf/0x190 drivers/net/wireless/ath/ath9k/htc_hst.c:501 ath9k_hif_usb_firmware_cb+0x42e/0xab0 drivers/net/wireless/ath/ath9k/hif_usb.c:1218 request_firmware_work_func+0x1aa/0x2d0 drivers/base/firmware_loader/main.c:1001 process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 kthread+0x551/0x590 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 Bytes 4-7 of 18 are uninitialized Memory access of size 18 starts at ffff8881d24f1000 ===================================================== --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.