aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorSergey Senozhatsky <sergey.senozhatsky@gmail.com>2016-10-18 00:41:12 +0900
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2016-10-20 16:35:50 +0200
commitc6fe46a79ecd79606bb96fada4515f6b23f87b62 (patch)
tree5832f2396a5ae91cf96f61a8542fb2c78e4170d6
parentc197d758036d8c77923ae3f88571cf198283107e (diff)
downloadlinux-stericsson-c6fe46a79ecd79606bb96fada4515f6b23f87b62.tar.gz
cpufreq: fix overflow in cpufreq_table_find_index_dl()
'best' is always less or equals to 'pos', so `best - pos' returns a negative value which is then getting casted to `unsigned int' and passed to __cpufreq_driver_target()->acpi_cpufreq_target() for policy->freq_table selection. This results in BUG: unable to handle kernel paging request at ffff881019b469f8 IP: [<ffffffffa00356c1>] acpi_cpufreq_target+0x4f/0x190 [acpi_cpufreq] PGD 267f067 PUD 0 Oops: 0000 [#1] PREEMPT SMP CPU: 6 PID: 70 Comm: kworker/6:1 Not tainted 4.9.0-rc1-next-20161017-dbg-dirty Workqueue: events dbs_work_handler task: ffff88041b808000 task.stack: ffff88041b810000 RIP: 0010:[<ffffffffa00356c1>] [<ffffffffa00356c1>] acpi_cpufreq_target+0x4f/0x190 [acpi_cpufreq] RSP: 0018:ffff88041b813c60 EFLAGS: 00010282 RAX: ffff880419b46a00 RBX: ffff88041b848400 RCX: ffff880419b20f80 RDX: 00000000001dff38 RSI: 00000000ffffffff RDI: ffff88041b848400 RBP: ffff88041b813cb0 R08: 0000000000000006 R09: 0000000000000040 R10: ffffffff8207f9e0 R11: ffffffff8173595b R12: 0000000000000000 R13: ffff88041f1dff38 R14: 0000000000262900 R15: 0000000bfffffff4 FS: 0000000000000000(0000) GS:ffff88041f000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff881019b469f8 CR3: 000000041a2d3000 CR4: 00000000001406e0 Stack: ffff88041b813cb0 ffffffff813347f9 ffff88041b813ca0 ffffffff81334663 ffff88041f1d4bc0 ffff88041b848400 0000000000000000 0000000000000000 0000000000262900 0000000000000000 ffff88041b813d00 ffffffff813355dc Call Trace: [<ffffffff813347f9>] ? cpufreq_freq_transition_begin+0xf1/0xfc [<ffffffff81334663>] ? get_cpu_idle_time+0x97/0xa6 [<ffffffff813355dc>] __cpufreq_driver_target+0x3b6/0x44e [<ffffffff81336ca3>] cs_dbs_timer+0x11a/0x135 [<ffffffff81336fda>] dbs_work_handler+0x39/0x62 [<ffffffff81057823>] process_one_work+0x280/0x4a5 [<ffffffff81058719>] worker_thread+0x24f/0x397 [<ffffffff810584ca>] ? rescuer_thread+0x30b/0x30b [<ffffffff81418380>] ? nl80211_get_key+0x29/0x36a [<ffffffff8105d2b7>] kthread+0xfc/0x104 [<ffffffff8107ceea>] ? put_lock_stats.isra.9+0xe/0x20 [<ffffffff8105d1bb>] ? kthread_create_on_node+0x3f/0x3f [<ffffffff814b2092>] ret_from_fork+0x22/0x30 Code: 56 4d 6b ff 0c 41 55 41 54 53 48 83 ec 28 48 8b 15 ad 1e 00 00 44 8b 41 08 48 8b 87 c8 00 00 00 49 89 d5 4e 03 2c c5 80 b2 78 81 <46> 8b 74 38 04 45 3b 75 00 75 11 31 c0 83 39 00 0f 84 1c 01 00 RIP [<ffffffffa00356c1>] acpi_cpufreq_target+0x4f/0x190 [acpi_cpufreq] RSP <ffff88041b813c60> CR2: ffff881019b469f8 ---[ end trace 16d9fc7a17897d37 ]--- [ rjw: In some cases this bug may also cause incorrect frequencies to be selected by cpufreq governors. ] Fixes: 899bb6642f2a (cpufreq: skip invalid entries when searching the frequency) Link: http://marc.info/?l=linux-kernel&m=147672030714331&w=2 Reported-and-tested-by: Sedat Dilek <sedat.dilek@gmail.com> Reported-and-tested-by: Jörg Otte <jrg.otte@gmail.com> Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.8+ <stable@vger.kernel.org> # 4.8+ Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
-rw-r--r--include/linux/cpufreq.h4
1 files changed, 2 insertions, 2 deletions
diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h
index 5fa55fc56e18..32dc0cbd51ca 100644
--- a/include/linux/cpufreq.h
+++ b/include/linux/cpufreq.h
@@ -677,10 +677,10 @@ static inline int cpufreq_table_find_index_dl(struct cpufreq_policy *policy,
if (best == table - 1)
return pos - table;
- return best - pos;
+ return best - table;
}
- return best - pos;
+ return best - table;
}
/* Works only on sorted freq-tables */