linux/drivers
Lars-Peter Clausen 4058ebf33c usb: gadget: ffs: Execute copy_to_user() with USER_DS set
When using a AIO read() operation on the function FS gadget driver a URB is
submitted asynchronously and on URB completion the received data is copied
to the userspace buffer associated with the read operation.

This is done from a kernel worker thread invoking copy_to_user() (through
copy_to_iter()). And while the user space process memory is made available
to the kernel thread using use_mm(), some architecture require in addition
to this that the operation runs with USER_DS set. Otherwise the userspace
memory access will fail.

For example on ARM64 with Privileged Access Never (PAN) and User Access
Override (UAO) enabled the following crash occurs.

	Internal error: Accessing user space memory with fs=KERNEL_DS: 9600004f [#1] SMP
	Modules linked in:
	CPU: 2 PID: 1636 Comm: kworker/2:1 Not tainted 4.9.0-04081-g8ab2dfb-dirty #487
	Hardware name: ZynqMP ZCU102 Rev1.0 (DT)
	Workqueue: events ffs_user_copy_worker
	task: ffffffc87afc8080 task.stack: ffffffc87a00c000
	PC is at __arch_copy_to_user+0x190/0x220
	LR is at copy_to_iter+0x78/0x3c8
	[...]
	[<ffffff800847b790>] __arch_copy_to_user+0x190/0x220
	[<ffffff80086f25d8>] ffs_user_copy_worker+0x70/0x130
	[<ffffff80080b8c64>] process_one_work+0x1dc/0x460
	[<ffffff80080b8f38>] worker_thread+0x50/0x4b0
	[<ffffff80080bf5a0>] kthread+0xd8/0xf0
	[<ffffff8008083680>] ret_from_fork+0x10/0x50

Address this by placing a set_fs(USER_DS) before of the copy operation
and revert it again once the copy operation has finished.

This patch is analogous to commit d7ffde35e3 ("vhost: use USER_DS in
vhost_worker thread") which addresses the same underlying issue.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
2018-03-13 10:47:39 +02:00
..
accessibility
acpi Merge branches 'acpi-ec', 'acpi-tables' and 'acpi-doc' 2018-02-15 12:02:42 +01:00
amba
android ANDROID: binder: synchronize_rcu() when using POLLFREE. 2018-02-16 11:16:38 +01:00
ata pci-v4.16-changes 2018-02-06 09:59:40 -08:00
atm atm: he: use 64-bit arithmetic instead of 32-bit 2018-02-08 15:05:16 -05:00
auxdisplay
base ACPI updates for v4.16-rc2 2018-02-15 14:50:32 -08:00
bcma
block Things have been very quiet on the rbd side, as work continues on the 2018-02-08 11:38:59 -08:00
bluetooth vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
bus ARM: SoC driver updates for 4.16 2018-02-01 16:35:31 -08:00
cdrom
char Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-14 17:02:15 -08:00
clk MIPS changes for 4.16 2018-02-07 11:22:44 -08:00
clocksource treewide/trivial: Remove ';;$' typo noise 2018-02-22 10:59:33 +01:00
connector
cpufreq Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-14 17:02:15 -08:00
cpuidle powerpc updates for 4.16 2018-02-02 10:01:04 -08:00
crypto Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6 2018-02-22 16:38:10 -08:00
dax Merge branch 'for-4.16/dax' into libnvdimm-for-next 2018-02-03 00:26:10 -07:00
dca
devfreq
dio
dma Merge branch 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm 2018-02-02 09:50:51 -08:00
dma-buf vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
edac Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-14 17:02:15 -08:00
eisa EISA: Delete error message for a failed memory allocation in eisa_probe() 2018-01-23 09:04:10 +01:00
extcon extcon: int3496: process id-pin first so that we start with the right status 2018-02-14 06:37:33 +09:00
firewire vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
firmware 2nd set of arm64 updates for 4.16: 2018-02-08 10:44:25 -08:00
fmc
fpga
fsi
gpio vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
gpu Merge branch 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-25 16:27:51 -08:00
hid usb: ldusb: add PIDs for new CASSY devices supported by this driver 2018-02-15 18:44:03 +01:00
hsi vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
hv vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
hwmon Fix bad temperature display on Ryzen/Threadripper 2018-02-15 14:31:28 -08:00
hwspinlock
hwtracing Char/Misc driver patches for 4.16-rc1 2018-02-01 10:31:17 -08:00
i2c i2c: designware: Consider SCL GPIO optional 2018-02-22 12:15:35 +01:00
ide pci-v4.16-changes 2018-02-06 09:59:40 -08:00
idle
iio First round of IIO fixes for the 4.16 cycle. 2018-02-20 10:03:22 +01:00
infiniband RDMA/uverbs: Fix kernel panic while using XRC_TGT QP type 2018-02-21 13:52:19 -05:00
input vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
iommu treewide/trivial: Remove ';;$' typo noise 2018-02-22 10:59:33 +01:00
ipack
irqchip irqchip/bcm: Remove hashed address printing 2018-02-16 14:22:16 +00:00
isdn vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
leds vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
lightnvm
macintosh powerpc/macio: set a proper dma_coherent_mask 2018-02-13 08:58:53 -08:00
mailbox vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
mcb
md treewide/trivial: Remove ';;$' typo noise 2018-02-22 10:59:33 +01:00
media vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
memory ARM: SoC driver updates for 4.16 2018-02-01 16:35:31 -08:00
memstick
message scsi: mptfusion: Add bounds check in mptctl_hp_targetinfo() 2018-01-30 21:32:06 -05:00
mfd vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
misc powerpc fixes for 4.16 #4 2018-02-24 16:05:50 -08:00
mmc mmc: bcm2835: Don't overwrite max frequency unconditionally 2018-02-14 11:30:10 +01:00
mtd mtd: nand: MTD_NAND_MARVELL should depend on HAS_DMA 2018-02-12 10:57:20 +01:00
mux Char/Misc driver patches for 4.16-rc1 2018-02-01 10:31:17 -08:00
net gianfar: simplify FCS handling and fix memory leak 2018-02-23 12:26:36 -05:00
nfc
ntb NTB: ntb_perf: fix cast to restricted __le32 2018-01-28 22:17:24 -05:00
nubus
nvdimm Merge branch 'for-4.16/nfit' into libnvdimm-for-next 2018-02-03 00:26:26 -07:00
nvme nvme-rdma: fix sysfs invoked reset_ctrl error flow 2018-02-14 15:44:22 +02:00
nvmem
of device property: Constify device_get_match_data() 2018-02-12 10:41:11 +01:00
opp opp: cpu: Replace GFP_ATOMIC with GFP_KERNEL in dev_pm_opp_init_cpufreq_table 2018-02-12 15:07:46 +05:30
oprofile
parisc
parport
pci PCI/cxgb4: Extend T3 PCI quirk to T4+ devices 2018-02-16 15:41:53 -05:00
pcmcia Merge branch 'pcmcia' of git://git.kernel.org/pub/scm/linux/kernel/git/brodo/pcmcia 2018-02-08 11:48:49 -08:00
perf arm_pmu: acpi: request IRQs up-front 2018-02-20 11:34:54 +00:00
phy USB/PHY updates for 4.16-rc1 2018-02-01 09:40:49 -08:00
pinctrl This is the bulk of pin control changes for the v4.16 kernel cycle: 2018-02-02 14:22:53 -08:00
platform platform/x86: dell-laptop: Removed duplicates in DMI whitelist 2018-02-15 12:18:33 +02:00
pnp
power power supply and reset changes for the v4.16 series 2018-01-31 12:55:31 -08:00
powercap
pps vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
ps3
ptp vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
pwm
rapidio vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
ras mm/memory_failure: Remove unused trapno from memory_failure 2018-01-23 12:17:42 -06:00
regulator regulator: Fix suspend to idle 2018-01-30 12:25:59 +00:00
remoteproc remoteproc updates for v4.16 2018-02-05 10:07:40 -08:00
reset
rpmsg vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
rtc vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
s390 virtio: bugfixes 2018-02-15 14:29:27 -08:00
sbus pci-v4.16-changes 2018-02-06 09:59:40 -08:00
scsi SCSI fixes on 20180222 2018-02-23 14:09:43 -08:00
sfi
sh cpufreq: Add and use cpufreq_for_each_{valid_,}entry_idx() 2018-02-08 10:21:39 +01:00
siox
slimbus
sn
soc treewide/trivial: Remove ';;$' typo noise 2018-02-22 10:59:33 +01:00
soundwire soundwire: Fix a signedness bug 2018-01-22 16:45:26 +01:00
spi Merge remote-tracking branch 'spi/topic/xilinx' into spi-next 2018-01-26 17:57:34 +00:00
spmi
ssb Merge git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers.git 2018-02-01 10:37:39 +02:00
staging Staging/IIO fixes for 4.16-rc2 2018-02-22 12:05:43 -08:00
target Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending 2018-02-09 14:49:46 -08:00
tc
tee
thermal Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux 2018-02-06 15:04:58 -08:00
thunderbolt
tty vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
uio vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
usb usb: gadget: ffs: Execute copy_to_user() with USER_DS set 2018-03-13 10:47:39 +02:00
uwb
vfio vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
vhost vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
video Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2018-02-14 17:02:15 -08:00
virt vfs: do bulk POLL* -> EPOLL* replacement 2018-02-11 14:34:03 -08:00
virtio virtio_pci: don't kfree device on register failure 2018-02-01 16:26:45 +02:00
visorbus
vlynq
vme
w1 Documentation updates for 4.16. New stuff includes refcount_t 2018-01-31 19:25:25 -08:00
watchdog linux-watchdog 4.16-rc1 merge window tag 2018-02-07 11:54:34 -08:00
xen mm, swap, frontswap: fix THP swap if frontswap enabled 2018-02-21 15:35:43 -08:00
zorro
Kconfig Char/Misc driver patches for 4.16-rc1 2018-02-01 10:31:17 -08:00
Makefile pci-v4.16-changes 2018-02-06 09:59:40 -08:00