linux_dsm_epyc7002/include
Stephen Boyd 3e779a2e7f gpio: Assign gpio_irq_chip::parents to non-stack pointer
gpiochip_set_cascaded_irqchip() is passed 'parent_irq' as an argument
and then the address of that argument is assigned to the gpio chips
gpio_irq_chip 'parents' pointer shortly thereafter. This can't ever
work, because we've just assigned some stack address to a pointer that
we plan to dereference later in gpiochip_irq_map(). I ran into this
issue with the KASAN report below when gpiochip_irq_map() tried to setup
the parent irq with a total junk pointer for the 'parents' array.

BUG: KASAN: stack-out-of-bounds in gpiochip_irq_map+0x228/0x248
Read of size 4 at addr ffffffc0dde472e0 by task swapper/0/1

CPU: 7 PID: 1 Comm: swapper/0 Not tainted 4.14.72 #34
Call trace:
[<ffffff9008093638>] dump_backtrace+0x0/0x718
[<ffffff9008093da4>] show_stack+0x20/0x2c
[<ffffff90096b9224>] __dump_stack+0x20/0x28
[<ffffff90096b91c8>] dump_stack+0x80/0xbc
[<ffffff900845a350>] print_address_description+0x70/0x238
[<ffffff900845a8e4>] kasan_report+0x1cc/0x260
[<ffffff900845aa14>] __asan_report_load4_noabort+0x2c/0x38
[<ffffff900897e098>] gpiochip_irq_map+0x228/0x248
[<ffffff900820cc08>] irq_domain_associate+0x114/0x2ec
[<ffffff900820d13c>] irq_create_mapping+0x120/0x234
[<ffffff900820da78>] irq_create_fwspec_mapping+0x4c8/0x88c
[<ffffff900820e2d8>] irq_create_of_mapping+0x180/0x210
[<ffffff900917114c>] of_irq_get+0x138/0x198
[<ffffff9008dc70ac>] spi_drv_probe+0x94/0x178
[<ffffff9008ca5168>] driver_probe_device+0x51c/0x824
[<ffffff9008ca6538>] __device_attach_driver+0x148/0x20c
[<ffffff9008ca14cc>] bus_for_each_drv+0x120/0x188
[<ffffff9008ca570c>] __device_attach+0x19c/0x2dc
[<ffffff9008ca586c>] device_initial_probe+0x20/0x2c
[<ffffff9008ca18bc>] bus_probe_device+0x80/0x154
[<ffffff9008c9b9b4>] device_add+0x9b8/0xbdc
[<ffffff9008dc7640>] spi_add_device+0x1b8/0x380
[<ffffff9008dcbaf0>] spi_register_controller+0x111c/0x1378
[<ffffff9008dd6b10>] spi_geni_probe+0x4dc/0x6f8
[<ffffff9008cab058>] platform_drv_probe+0xdc/0x130
[<ffffff9008ca5168>] driver_probe_device+0x51c/0x824
[<ffffff9008ca59cc>] __driver_attach+0x100/0x194
[<ffffff9008ca0ea8>] bus_for_each_dev+0x104/0x16c
[<ffffff9008ca58c0>] driver_attach+0x48/0x54
[<ffffff9008ca1edc>] bus_add_driver+0x274/0x498
[<ffffff9008ca8448>] driver_register+0x1ac/0x230
[<ffffff9008caaf6c>] __platform_driver_register+0xcc/0xdc
[<ffffff9009c4b33c>] spi_geni_driver_init+0x1c/0x24
[<ffffff9008084cb8>] do_one_initcall+0x240/0x3dc
[<ffffff9009c017d0>] kernel_init_freeable+0x378/0x468
[<ffffff90096e8240>] kernel_init+0x14/0x110
[<ffffff9008086fcc>] ret_from_fork+0x10/0x18

The buggy address belongs to the page:
page:ffffffbf037791c0 count:0 mapcount:0 mapping:          (null) index:0x0
flags: 0x4000000000000000()
raw: 4000000000000000 0000000000000000 0000000000000000 00000000ffffffff
raw: ffffffbf037791e0 ffffffbf037791e0 0000000000000000 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffffffc0dde47180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffc0dde47200: f1 f1 f1 f1 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f2 f2
>ffffffc0dde47280: f2 f2 00 00 00 00 00 00 00 00 00 00 f3 f3 f3 f3
                                                       ^
 ffffffc0dde47300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffffc0dde47380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

Let's leave around one unsigned int in the gpio_irq_chip struct for the
single parent irq case and repoint the 'parents' array at it. This way
code is left mostly intact to setup parents and we waste an extra few
bytes per structure of which there should be only a handful in a system.

Cc: Evan Green <evgreen@chromium.org>
Cc: Thierry Reding <treding@nvidia.com>
Cc: Grygorii Strashko <grygorii.strashko@ti.com>
Fixes: e0d8972898 ("gpio: Implement tighter IRQ chip integration")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2018-10-10 14:03:27 +02:00
..
acpi ACPICA: Update version to 20180810 2018-08-14 23:49:13 +02:00
asm-generic asm-generic: io: Fix ioport_map() for !CONFIG_GENERIC_IOMAP && CONFIG_INDIRECT_PIO 2018-09-14 09:49:21 +01:00
clocksource
crypto crypto: scatterwalk - remove scatterwalk_samebuf() 2018-08-03 18:06:04 +08:00
drm drm/cma-helper: Fix crash in fbdev error path 2018-10-02 13:03:34 +02:00
dt-bindings ARM: SoC: late updates 2018-08-25 14:12:36 -07:00
keys
kvm KVM: arm/arm64: vgic-v3: Add core support for Group0 SGIs 2018-08-12 12:06:34 +01:00
linux gpio: Assign gpio_irq_chip::parents to non-stack pointer 2018-10-10 14:03:27 +02:00
math-emu
media media: v4l: event: Prevent freeing event subscriptions while accessed 2018-10-03 06:32:51 -04:00
memory
misc
net inet: make sure to grab rcu_read_lock before using ireq->ireq_opt 2018-10-02 15:52:12 -07:00
pcmcia pcmcia: remove long deprecated pcmcia_request_exclusive_irq() function 2018-08-18 12:30:42 -07:00
ras
rdma Second merge window update 2018-08-23 15:34:48 -07:00
scsi SCSI misc on 20180815 2018-08-15 22:06:26 -07:00
soc
sound ASoC: Fixes for v4.19 2018-09-17 18:59:21 +02:00
target scsi: target: add session removal function 2018-08-02 15:29:31 -04:00
trace Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-10-05 15:39:38 -07:00
uapi mm/hugetlb: add mmap() encodings for 32MB and 512MB page sizes 2018-10-05 16:32:04 -07:00
video fbdev changes for v4.19: 2018-08-23 15:44:58 -07:00
xen xen/balloon: add runtime control for scrubbing ballooned out pages 2018-09-14 08:51:10 -04:00