syzbot has found a reproducer for 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=12985a16900000 kernel config: https://syzkaller.appspot.com/x/.config?x=3afe005fb99591f dashboard link: https://syzkaller.appspot.com/bug?extid=2ca247c2d60c7023de7f compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1468efe2900000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10bb9fba900000 IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+2ca247c2d60c7023de7f@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in ath9k_htc_rx_msg+0x28f/0x1f50 drivers/net/wireless/ath/ath9k/htc_hst.c:410 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.8.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __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 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 ath9k_htc_rx_msg+0x28f/0x1f50 drivers/net/wireless/ath/ath9k/htc_hst.c:410 ath9k_hif_usb_rx_stream drivers/net/wireless/ath/ath9k/hif_usb.c:638 [inline] ath9k_hif_usb_rx_cb+0x1841/0x1d10 drivers/net/wireless/ath/ath9k/hif_usb.c:671 __usb_hcd_giveback_urb+0x687/0x870 drivers/usb/core/hcd.c:1650 usb_hcd_giveback_urb+0x1cb/0x730 drivers/usb/core/hcd.c:1716 dummy_timer+0xd98/0x71c0 drivers/usb/gadget/udc/dummy_hcd.c:1967 call_timer_fn+0x226/0x550 kernel/time/timer.c:1404 expire_timers+0x4fc/0x780 kernel/time/timer.c:1449 __run_timers+0xaf4/0xd30 kernel/time/timer.c:1773 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786 __do_softirq+0x2ea/0x7f5 kernel/softirq.c:293 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:711 </IRQ> __run_on_irqstack arch/x86/include/asm/irq_stack.h:23 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] do_softirq_own_stack+0x7c/0xa0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:390 [inline] __irq_exit_rcu+0x226/0x270 kernel/softirq.c:420 irq_exit_rcu+0xe/0x10 kernel/softirq.c:432 sysvec_apic_timer_interrupt+0x107/0x130 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:593 RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:49 [inline] RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:89 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline] RIP: 0010:acpi_idle_do_entry drivers/acpi/processor_idle.c:525 [inline] RIP: 0010:acpi_idle_enter+0x817/0xeb0 drivers/acpi/processor_idle.c:651 Code: 85 db 74 0a f7 d3 44 21 fb 48 85 db 74 32 4d 85 ff 75 3a 48 8b 5d a0 e9 0c 00 00 00 e8 12 b2 78 fb 0f 00 2d 25 15 1c 0b fb f4 <fa> eb 5a 84 c0 8b 7d 90 0f 45 7d 94 e8 d8 9a f4 fb e9 74 fc ff ff RSP: 0018:ffff88812df93bc8 EFLAGS: 00000246 RAX: 0000000000000000 RBX: ffff8881dfefce70 RCX: 000000012db88000 RDX: ffff88812df88000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff88812df93ca0 R08: ffffffff86420acc R09: ffff88812fffa000 R10: 0000000000000002 R11: ffff88812df88000 R12: ffff88812df889d8 R13: ffff8881dfefcc64 R14: 0000000000000000 R15: 0000000000000000 cpuidle_enter_state+0x860/0x12b0 drivers/cpuidle/cpuidle.c:235 cpuidle_enter+0xe3/0x170 drivers/cpuidle/cpuidle.c:346 call_cpuidle kernel/sched/idle.c:126 [inline] cpuidle_idle_call kernel/sched/idle.c:214 [inline] do_idle+0x668/0x810 kernel/sched/idle.c:276 cpu_startup_entry+0x45/0x50 kernel/sched/idle.c:372 start_secondary+0x1bf/0x240 arch/x86/kernel/smpboot.c:268 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243 Uninit was created at: kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144 kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:269 [inline] kmsan_alloc_page+0xc5/0x1a0 mm/kmsan/kmsan_shadow.c:293 __alloc_pages_nodemask+0xdf0/0x1030 mm/page_alloc.c:4889 __alloc_pages include/linux/gfp.h:509 [inline] __alloc_pages_node include/linux/gfp.h:522 [inline] alloc_pages_node include/linux/gfp.h:536 [inline] __page_frag_cache_refill mm/page_alloc.c:4964 [inline] page_frag_alloc+0x35b/0x880 mm/page_alloc.c:4994 __netdev_alloc_skb+0x2a8/0xc90 net/core/skbuff.c:451 __dev_alloc_skb include/linux/skbuff.h:2813 [inline] ath9k_hif_usb_rx_stream drivers/net/wireless/ath/ath9k/hif_usb.c:620 [inline] ath9k_hif_usb_rx_cb+0xe5a/0x1d10 drivers/net/wireless/ath/ath9k/hif_usb.c:671 __usb_hcd_giveback_urb+0x687/0x870 drivers/usb/core/hcd.c:1650 usb_hcd_giveback_urb+0x1cb/0x730 drivers/usb/core/hcd.c:1716 dummy_timer+0xd98/0x71c0 drivers/usb/gadget/udc/dummy_hcd.c:1967 call_timer_fn+0x226/0x550 kernel/time/timer.c:1404 expire_timers+0x4fc/0x780 kernel/time/timer.c:1449 __run_timers+0xaf4/0xd30 kernel/time/timer.c:1773 run_timer_softirq+0x2d/0x50 kernel/time/timer.c:1786 __do_softirq+0x2ea/0x7f5 kernel/softirq.c:293 =====================================================