From: Sasha Levin <sasha.levin@oracle.com>
To: Peter Zijlstra <peterz@infradead.org>,
Ingo Molnar <mingo@kernel.org>,
Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: LKML <linux-kernel@vger.kernel.org>
Subject: perf/ring-buffer: Undefined behaviour in kernel/events/ring_buffer.c:685:22
Date: Sun, 10 Jan 2016 15:55:13 -0500 [thread overview]
Message-ID: <5692C531.1030302@oracle.com> (raw)
Hi all,
While fuzzing with trinity inside a KVM tools guest, running the latest -next
kernel, I've hit the following warning:
[ 3494.030114] UBSAN: Undefined behaviour in kernel/events/ring_buffer.c:685:22
[ 3494.030647] shift exponent -1 is negative
[ 3494.031025] CPU: 1 PID: 28506 Comm: kworker/1:2 Not tainted 4.4.0-rc8-next-20160108-sasha-00024-gaaecb9a #2780
[ 3494.032861] Workqueue: events rb_free_work
[ 3494.033195] 1ffff10018bb2f1b 0000000025cc19e7 ffff8800c5d97958 ffffffffa101a182
[ 3494.033871] 0000000041b58ab3 ffffffffac1b3838 ffffffffa101a0b7 ffff8800c5d97920
[ 3494.034469] ffffffffae01db80 ffff8800c5d97940 0000000025cc19e7 ffffffffae01db80
[ 3494.035097] Call Trace:
[ 3494.035336] [<ffffffffa101a182>] dump_stack+0xcb/0x149
[ 3494.036171] [<ffffffffa1114296>] ubsan_epilogue+0x12/0x8f
[ 3494.036568] [<ffffffffa1114e9a>] __ubsan_handle_shift_out_of_bounds+0x2a3/0x308
[ 3494.038670] [<ffffffff9f6274ee>] rb_free_work+0xae/0x1a0
[ 3494.039491] [<ffffffff9f3ac74c>] process_one_work+0xb6c/0x13d0
[ 3494.042924] [<ffffffff9f3adce3>] worker_thread+0xd33/0x1150
[ 3494.043923] [<ffffffff9f3c4239>] kthread+0x2f9/0x310
Thanks,
Sasha
next reply other threads:[~2016-01-10 20:55 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-10 20:55 Sasha Levin [this message]
2016-01-19 14:31 ` perf/ring-buffer: Undefined behaviour in kernel/events/ring_buffer.c:685:22 Peter Zijlstra
2016-01-21 23:34 ` Sasha Levin
2016-01-22 12:48 ` Andrey Ryabinin
2016-01-29 14:17 ` Peter Zijlstra
2016-03-21 9:51 ` [tip:perf/urgent] perf/core: Fix Undefined behaviour in rb_alloc() tip-bot for Peter Zijlstra
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