forked from Minki/linux
305d568b72
The FSM can run in a circle allowing rdma_resolve_ip() to be called twice
on the same id_priv. While this cannot happen without going through the
work, it violates the invariant that the same address resolution
background request cannot be active twice.
CPU 1 CPU 2
rdma_resolve_addr():
RDMA_CM_IDLE -> RDMA_CM_ADDR_QUERY
rdma_resolve_ip(addr_handler) #1
process_one_req(): for #1
addr_handler():
RDMA_CM_ADDR_QUERY -> RDMA_CM_ADDR_BOUND
mutex_unlock(&id_priv->handler_mutex);
[.. handler still running ..]
rdma_resolve_addr():
RDMA_CM_ADDR_BOUND -> RDMA_CM_ADDR_QUERY
rdma_resolve_ip(addr_handler)
!! two requests are now on the req_list
rdma_destroy_id():
destroy_id_handler_unlock():
_destroy_id():
cma_cancel_operation():
rdma_addr_cancel()
// process_one_req() self removes it
spin_lock_bh(&lock);
cancel_delayed_work(&req->work);
if (!list_empty(&req->list)) == true
! rdma_addr_cancel() returns after process_on_req #1 is done
kfree(id_priv)
process_one_req(): for #2
addr_handler():
mutex_lock(&id_priv->handler_mutex);
!! Use after free on id_priv
rdma_addr_cancel() expects there to be one req on the list and only
cancels the first one. The self-removal behavior of the work only happens
after the handler has returned. This yields a situations where the
req_list can have two reqs for the same "handle" but rdma_addr_cancel()
only cancels the first one.
The second req remains active beyond rdma_destroy_id() and will
use-after-free id_priv once it inevitably triggers.
Fix this by remembering if the id_priv has called rdma_resolve_ip() and
always cancel before calling it again. This ensures the req_list never
gets more than one item in it and doesn't cost anything in the normal flow
that never uses this strange error path.
Link: https://lore.kernel.org/r/0-v1-3bc675b8006d+22-syz_cancel_uaf_jgg@nvidia.com
Cc: stable@vger.kernel.org
Fixes:
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.. | ||
accessibility | ||
acpi | ||
amba | ||
android | ||
ata | ||
atm | ||
auxdisplay | ||
base | ||
bcma | ||
block | ||
bluetooth | ||
bus | ||
cdrom | ||
char | ||
clk | ||
clocksource | ||
comedi | ||
connector | ||
counter | ||
cpufreq | ||
cpuidle | ||
crypto | ||
cxl | ||
dax | ||
dca | ||
devfreq | ||
dio | ||
dma | ||
dma-buf | ||
edac | ||
eisa | ||
extcon | ||
firewire | ||
firmware | ||
fpga | ||
fsi | ||
gnss | ||
gpio | ||
gpu | ||
greybus | ||
hid | ||
hsi | ||
hv | ||
hwmon | ||
hwspinlock | ||
hwtracing | ||
i2c | ||
i3c | ||
idle | ||
iio | ||
infiniband | ||
input | ||
interconnect | ||
iommu | ||
ipack | ||
irqchip | ||
isdn | ||
leds | ||
macintosh | ||
mailbox | ||
mcb | ||
md | ||
media | ||
memory | ||
memstick | ||
message | ||
mfd | ||
misc | ||
mmc | ||
most | ||
mtd | ||
mux | ||
net | ||
nfc | ||
ntb | ||
nubus | ||
nvdimm | ||
nvme | ||
nvmem | ||
of | ||
opp | ||
parisc | ||
parport | ||
pci | ||
pcmcia | ||
perf | ||
phy | ||
pinctrl | ||
platform | ||
pnp | ||
power | ||
powercap | ||
pps | ||
ps3 | ||
ptp | ||
pwm | ||
rapidio | ||
ras | ||
regulator | ||
remoteproc | ||
reset | ||
rpmsg | ||
rtc | ||
s390 | ||
sbus | ||
scsi | ||
sh | ||
siox | ||
slimbus | ||
soc | ||
soundwire | ||
spi | ||
spmi | ||
ssb | ||
staging | ||
target | ||
tc | ||
tee | ||
thermal | ||
thunderbolt | ||
tty | ||
uio | ||
usb | ||
vdpa | ||
vfio | ||
vhost | ||
video | ||
virt | ||
virtio | ||
visorbus | ||
vlynq | ||
vme | ||
w1 | ||
watchdog | ||
xen | ||
zorro | ||
Kconfig | ||
Makefile |