Bug 208237
| Summary: | INFO: rcu detected stall in tty_write bug | ||
|---|---|---|---|
| Product: | Drivers | Reporter: | tkeri (tkeri) |
| Component: | Console/Framebuffers | Assignee: | James Simmons (jsimmons) |
| Status: | NEW --- | ||
| Severity: | normal | ||
| Priority: | P1 | ||
| Hardware: | x86-64 | ||
| OS: | Linux | ||
| Kernel Version: | 5.7.0+ | Subsystem: | |
| Regression: | No | Bisected commit-id: | |
| Attachments: |
Linux config
Syzkaller reproducer C reproducer |
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Created attachment 289741 [details]
Syzkaller reproducer
Created attachment 289743 [details]
C reproducer
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Created attachment 289739 [details] Linux config audit: type=1400 audit(1591452021.709:8): avc: denied { execmem } for pid=388 comm="syz-executor772" scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=process permissive=1 rcu: INFO: rcu_sched self-detected stall on CPU rcu: 1-....: (10497 ticks this GP) idle=2f6/1/0x4000000000000002 softirq=2661/2661 fqs=5119 (t=21000 jiffies g=3217 q=17) NMI backtrace for cpu 1 CPU: 1 PID: 394 Comm: syz-executor772 Not tainted 5.7.0+ #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: <IRQ> dump_stack+0xb4/0xfe lib/dump_stack.c:77 nmi_cpu_backtrace.cold.7+0x19/0x7d lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x164/0x19b lib/nmi_backtrace.c:62 rcu_dump_cpu_stacks+0xfb/0x140 include/linux/nmi.h:164 rcu_sched_clock_irq.cold.88+0xa8/0x4c5 kernel/rcu/tree_stall.h:553 update_process_times+0x24/0x70 kernel/time/timer.c:1727 tick_sched_handle+0xb4/0xd0 kernel/time/tick-sched.c:176 tick_sched_timer+0x3c/0xc0 kernel/time/tick-sched.c:1320 __hrtimer_run_queues+0x260/0x5a0 kernel/time/hrtimer.c:1520 hrtimer_interrupt+0x1e0/0x3f0 kernel/time/hrtimer.c:1646 smp_apic_timer_interrupt+0x83/0x1d0 arch/x86/kernel/apic/apic.c:1080 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 </IRQ> RIP: 0010:memcpy_erms+0x6/0x10 arch/x86/lib/memcpy_64.S:56 Code: ce fe ff ff eb 1e 0f 1f 00 48 89 f8 48 89 d1 48 c1 e9 03 83 e2 07 f3 48 a5 89 d1 f3 a4 c3 66 0f 1f 44 00 00 48 89 f8 48 89 d1 <f3> a4 c3 0f 1f 80 00 00 00 00 48 89 f8 48 83 fa 20 72 7e 40 38 fe RSP: 0018:ffffc900002b7900 EFLAGS: 00010202 ORIG_RAX: ffffffffffffff13 RAX: ffff8880000b8000 RBX: ffff88806cc30800 RCX: 0000000000006000 RDX: 0000000000007ff8 RSI: ffff8880000ba000 RDI: ffff8880000b9ff8 RBP: 0000000000000001 R08: ffffed1000017fff R09: ffffed1000017fff R10: ffff8880000bfff7 R11: ffffed1000017ffe R12: 0000000000000008 R13: ffff88806cc309a8 R14: ffff8880000b8000 R15: ffff88806cc30980 vgacon_scroll+0x599/0x5b0 include/linux/vt_buffer.h:49 con_scroll+0x303/0x420 drivers/tty/vt/vt.c:637 lf+0x19d/0x1b0 drivers/tty/vt/vt.c:1483 do_con_write.part.25+0x10ad/0x1420 drivers/tty/vt/vt.c:2781 con_write+0x3f/0xc0 drivers/tty/vt/vt.c:2593 n_tty_write+0x836/0xa00 drivers/tty/n_tty.c:2356 tty_write+0x33a/0x640 drivers/tty/tty_io.c:962 __vfs_write+0x50/0xa0 fs/read_write.c:495 vfs_write+0x169/0x350 fs/read_write.c:559 ksys_write+0xe3/0x1d0 fs/read_write.c:612 do_syscall_64+0x8a/0x2b0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x44b789 Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffd07540b08 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000044b789 RDX: 0000000000001000 RSI: 0000000020001100 RDI: 0000000000000005 RBP: 00007ffd07540b14 R08: 000000000000000d R09: 0000000907540c68 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 000000000002ae5d R14: 00000000006bc018 R15: 0000000000000000