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| author | Vasily Gorbik <gor@linux.ibm.com> | 2019-09-17 23:59:03 +0300 |
|---|---|---|
| committer | Vasily Gorbik <gor@linux.ibm.com> | 2019-09-24 00:27:52 +0300 |
| commit | f3122a79a1b0a113d3aea748e0ec26f2cb2889de (patch) | |
| tree | 4cc01226de283abbb3cd2e357f998c2f5f83e1ea | |
| parent | 93426cadc339939d723a71fa1e2fdbfb97773ef0 (diff) | |
| download | linux-f3122a79a1b0a113d3aea748e0ec26f2cb2889de.tar.xz | |
s390/topology: avoid firing events before kobjs are created
arch_update_cpu_topology is first called from:
kernel_init_freeable->sched_init_smp->sched_init_domains
even before cpus has been registered in:
kernel_init_freeable->do_one_initcall->s390_smp_init
Do not trigger kobject_uevent change events until cpu devices are
actually created. Fixes the following kasan findings:
BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb40/0xee0
Read of size 8 at addr 0000000000000020 by task swapper/0/1
BUG: KASAN: global-out-of-bounds in kobject_uevent_env+0xb36/0xee0
Read of size 8 at addr 0000000000000018 by task swapper/0/1
CPU: 0 PID: 1 Comm: swapper/0 Tainted: G B
Hardware name: IBM 3906 M04 704 (LPAR)
Call Trace:
([<0000000143c6db7e>] show_stack+0x14e/0x1a8)
[<0000000145956498>] dump_stack+0x1d0/0x218
[<000000014429fb4c>] print_address_description+0x64/0x380
[<000000014429f630>] __kasan_report+0x138/0x168
[<0000000145960b96>] kobject_uevent_env+0xb36/0xee0
[<0000000143c7c47c>] arch_update_cpu_topology+0x104/0x108
[<0000000143df9e22>] sched_init_domains+0x62/0xe8
[<000000014644c94a>] sched_init_smp+0x3a/0xc0
[<0000000146433a20>] kernel_init_freeable+0x558/0x958
[<000000014599002a>] kernel_init+0x22/0x160
[<00000001459a71d4>] ret_from_fork+0x28/0x30
[<00000001459a71dc>] kernel_thread_starter+0x0/0x10
Cc: stable@vger.kernel.org
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
| -rw-r--r-- | arch/s390/kernel/topology.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/arch/s390/kernel/topology.c b/arch/s390/kernel/topology.c index 2db6fb405a9a..3627953007ed 100644 --- a/arch/s390/kernel/topology.c +++ b/arch/s390/kernel/topology.c @@ -311,7 +311,8 @@ int arch_update_cpu_topology(void) on_each_cpu(__arch_update_dedicated_flag, NULL, 0); for_each_online_cpu(cpu) { dev = get_cpu_device(cpu); - kobject_uevent(&dev->kobj, KOBJ_CHANGE); + if (dev) + kobject_uevent(&dev->kobj, KOBJ_CHANGE); } return rc; } |