linux-brain/include/linux/spi
William A. Kennington III 001c8e8364 spi: Fix use-after-free with devm_spi_alloc_*
[ Upstream commit 794aaf01444d4e765e2b067cba01cc69c1c68ed9 ]

We can't rely on the contents of the devres list during
spi_unregister_controller(), as the list is already torn down at the
time we perform devres_find() for devm_spi_release_controller. This
causes devices registered with devm_spi_alloc_{master,slave}() to be
mistakenly identified as legacy, non-devm managed devices and have their
reference counters decremented below 0.

------------[ cut here ]------------
WARNING: CPU: 1 PID: 660 at lib/refcount.c:28 refcount_warn_saturate+0x108/0x174
[<b0396f04>] (refcount_warn_saturate) from [<b03c56a4>] (kobject_put+0x90/0x98)
[<b03c5614>] (kobject_put) from [<b0447b4c>] (put_device+0x20/0x24)
 r4:b6700140
[<b0447b2c>] (put_device) from [<b07515e8>] (devm_spi_release_controller+0x3c/0x40)
[<b07515ac>] (devm_spi_release_controller) from [<b045343c>] (release_nodes+0x84/0xc4)
 r5:b6700180 r4:b6700100
[<b04533b8>] (release_nodes) from [<b0454160>] (devres_release_all+0x5c/0x60)
 r8:b1638c54 r7:b117ad94 r6:b1638c10 r5:b117ad94 r4:b163dc10
[<b0454104>] (devres_release_all) from [<b044e41c>] (__device_release_driver+0x144/0x1ec)
 r5:b117ad94 r4:b163dc10
[<b044e2d8>] (__device_release_driver) from [<b044f70c>] (device_driver_detach+0x84/0xa0)
 r9:00000000 r8:00000000 r7:b117ad94 r6:b163dc54 r5:b1638c10 r4:b163dc10
[<b044f688>] (device_driver_detach) from [<b044d274>] (unbind_store+0xe4/0xf8)

Instead, determine the devm allocation state as a flag on the
controller which is guaranteed to be stable during cleanup.

Fixes: 5e844cc37a5c ("spi: Introduce device-managed SPI controller allocation")
Signed-off-by: William A. Kennington III <wak@google.com>
Link: https://lore.kernel.org/r/20210407095527.2771582-1-wak@google.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2021-05-14 09:44:20 +02:00
..
ad7877.h
ads7846.h
at73c213.h
at86rf230.h
cc2520.h
corgi_lcd.h
ds1305.h
eeprom.h
flash.h
ifx_modem.h
l4f00242t03.h
libertas_spi.h
lms283gf05.h
max7301.h
mc33880.h
mcp23s08.h
mmc_spi.h
mxs-spi.h
pxa2xx_spi.h
rspi.h
s3c24xx.h
sh_hspi.h
sh_msiof.h
spi-fsl-dspi.h
spi-mem.h
spi.h spi: Fix use-after-free with devm_spi_alloc_* 2021-05-14 09:44:20 +02:00
spi_bitbang.h
spi_gpio.h
spi_oc_tiny.h
tdo24m.h
tle62x0.h
xilinx_spi.h