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| author | Vasily Gorbik <gor@linux.ibm.com> | 2019-09-19 16:55:17 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-10-11 19:20:43 +0300 |
| commit | 46cb14a570889a693c4ca24c0a6d4be4dc18f8f4 (patch) | |
| tree | b48a1a8d9d2280b233eaff099a50b74bc6f84ccc /drivers/s390 | |
| parent | 9aa823b3c0a6997092c5e0f7efc63d27479afb42 (diff) | |
| download | linux-46cb14a570889a693c4ca24c0a6d4be4dc18f8f4.tar.xz | |
s390/cio: exclude subchannels with no parent from pseudo check
commit ab5758848039de9a4b249d46e4ab591197eebaf2 upstream.
ccw console is created early in start_kernel and used before css is
initialized or ccw console subchannel is registered. Until then console
subchannel does not have a parent. For that reason assume subchannels
with no parent are not pseudo subchannels. This fixes the following
kasan finding:
BUG: KASAN: global-out-of-bounds in sch_is_pseudo_sch+0x8e/0x98
Read of size 8 at addr 00000000000005e8 by task swapper/0/0
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.3.0-rc8-07370-g6ac43dd12538 #2
Hardware name: IBM 2964 NC9 702 (z/VM 6.4.0)
Call Trace:
([<000000000012cd76>] show_stack+0x14e/0x1e0)
[<0000000001f7fb44>] dump_stack+0x1a4/0x1f8
[<00000000007d7afc>] print_address_description+0x64/0x3c8
[<00000000007d75f6>] __kasan_report+0x14e/0x180
[<00000000018a2986>] sch_is_pseudo_sch+0x8e/0x98
[<000000000189b950>] cio_enable_subchannel+0x1d0/0x510
[<00000000018cac7c>] ccw_device_recognition+0x12c/0x188
[<0000000002ceb1a8>] ccw_device_enable_console+0x138/0x340
[<0000000002cf1cbe>] con3215_init+0x25e/0x300
[<0000000002c8770a>] console_init+0x68a/0x9b8
[<0000000002c6a3d6>] start_kernel+0x4fe/0x728
[<0000000000100070>] startup_continue+0x70/0xd0
Cc: stable@vger.kernel.org
Reviewed-by: Sebastian Ott <sebott@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/s390')
| -rw-r--r-- | drivers/s390/cio/css.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index aea502922646..df09ed53ab45 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -1213,6 +1213,8 @@ device_initcall(cio_settle_init); int sch_is_pseudo_sch(struct subchannel *sch) { + if (!sch->dev.parent) + return 0; return sch == to_css(sch->dev.parent)->pseudo_subchannel; } |