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| author | Vladimir Murzin <vladimir.murzin@arm.com> | 2015-03-06 16:37:45 +0000 |
|---|---|---|
| committer | Jason Cooper <jason@lakedaemon.net> | 2015-03-08 05:33:29 +0000 |
| commit | 614be385521b08b849da1098625da591984738c0 (patch) | |
| tree | 3cec5c193cac9f8d563c633c2571fe34185b60af /drivers/irqchip/irq-gic-v3.c | |
| parent | cf613871946230c5dd8178d07bcdc2984f4545cd (diff) | |
| download | lwn-614be385521b08b849da1098625da591984738c0.tar.gz lwn-614be385521b08b849da1098625da591984738c0.zip | |
irqchip: gic-v3: Fix out of bounds access to cpu_logical_map
While playing with KASan support for arm64/arm the following appeared on boot:
==================================================================
BUG: AddressSanitizer: out of bounds access in __asan_load8+0x14/0x1c at addr ffffffc000ad0dc0
Read of size 8 by task swapper/0/1
page:ffffffbdc202b400 count:1 mapcount:0 mapping: (null) index:0x0
flags: 0x400(reserved)
page dumped because: kasan: bad access detected
Address belongs to variable __cpu_logical_map+0x200/0x220
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc6-next-20150129+ #481
Hardware name: FVP Base (DT)
Call trace:
[<ffffffc00008a794>] dump_backtrace+0x0/0x184
[<ffffffc00008a928>] show_stack+0x10/0x1c
[<ffffffc00075e46c>] dump_stack+0xa0/0xf8
[<ffffffc0001df490>] kasan_report_error+0x23c/0x264
[<ffffffc0001e0188>] check_memory_region+0xc0/0xe4
[<ffffffc0001dedf0>] __asan_load8+0x10/0x1c
[<ffffffc000431294>] gic_raise_softirq+0xc4/0x1b4
[<ffffffc000091fc0>] smp_send_reschedule+0x30/0x3c
[<ffffffc0000f0d1c>] try_to_wake_up+0x394/0x434
[<ffffffc0000f0de8>] wake_up_process+0x2c/0x6c
[<ffffffc0000d9570>] wake_up_worker+0x38/0x48
[<ffffffc0000dbb50>] insert_work+0xac/0xec
[<ffffffc0000dbd38>] __queue_work+0x1a8/0x374
[<ffffffc0000dbf60>] queue_work_on+0x5c/0x7c
[<ffffffc0000d8a78>] call_usermodehelper_exec+0x170/0x188
[<ffffffc0004037b8>] kobject_uevent_env+0x650/0x6bc
[<ffffffc000403830>] kobject_uevent+0xc/0x18
[<ffffffc00040292c>] kset_register+0xa8/0xc8
[<ffffffc0004d6c88>] bus_register+0x134/0x2e8
[<ffffffc0004d73b4>] subsys_virtual_register+0x2c/0x5c
[<ffffffc000a76a4c>] wq_sysfs_init+0x14/0x20
[<ffffffc000082a28>] do_one_initcall+0xa8/0x1fc
[<ffffffc000a70db4>] kernel_init_freeable+0x1ec/0x294
[<ffffffc00075aa5c>] kernel_init+0xc/0xec
Memory state around the buggy address:
ffffff80003e0820: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffff80003e0830: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffff80003e0840: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
^
ffffff80003e0850: 00 00 fa fa fa fa fa fa 00 00 00 00 00 00 00 00
==================================================================
The reason for that cpumask_next() returns >= nr_cpu_ids if no further cpus
set, but "==" condition is checked only, so we end up with out-of-bounds
access to cpu_logical_map.
Fix is by using the condition check for cpumask_next.
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Link: https://lkml.kernel.org/r/1425659870-11832-7-git-send-email-marc.zyngier@arm.com
Signed-off-by: Jason Cooper <jason@lakedaemon.net>
Diffstat (limited to 'drivers/irqchip/irq-gic-v3.c')
| -rw-r--r-- | drivers/irqchip/irq-gic-v3.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 1c6dea2fbc34..fd8850def1b8 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -466,7 +466,7 @@ static u16 gic_compute_target_list(int *base_cpu, const struct cpumask *mask, tlist |= 1 << (mpidr & 0xf); cpu = cpumask_next(cpu, mask); - if (cpu == nr_cpu_ids) + if (cpu >= nr_cpu_ids) goto out; mpidr = cpu_logical_map(cpu); |