[PATCH RFC v2 0/6] staging: r8188eu: avoid uninit value bugs

Pavel Skripkin
2021-08-22T14:35:23Z

Hi, Greg, Larry and Phillip!

I noticed, that new staging driver was added like 3 weeks ago and I decided
to look at the code, because drivers in staging directory are always buggy.

The first thing I noticed is *no one* was checking read operations result, but
it can fail and driver may start writing random stack values into registers. It
can cause driver misbehavior or device misbehavior.

To avoid this type of bugs, i've changed rtw_read* API. Now all rtw_read
funtions return an error, when something went wrong with usb transfer.

It helps callers to break/return earlier and don't write random values to
registers or to rely on random values.

Why is this pacth series RFC?
1. I don't have this device and I cannot test these changes.
2. I don't know how to handle errors in each particular case. For now, function
just returns or returns an error. That's all. I hope, driver maintainers will
help with these bits.
3. I guess, I handled not all uninit value bugs here. I hope, I fixed
at least half of them

v1 -> v2:
1. Make rtw_read*() return an error instead of initializing pointer to error
2. Split one huge patch to smaller ones for each rtw_read{8,16,32} function
changes
3. Add new macro for printing register values (It helps to not copy-paste error
handling)
4. Removed {read,write}_macreg (Suggested by Phillip)
5. Rebased on top of staging-next
6. Cleaned checkpatch errors and warnings

Only build-tested, since I don't have device with r8118eu chip

Pavel Skripkin (6):
staging: r8188eu: remove {read,write}_macreg
staging: r8188eu: add helper macro for printing registers
staging: r8188eu: add error handling of rtw_read8
staging: r8188eu: add error handling of rtw_read16
staging: r8188eu: add error handling of rtw_read32
staging: r8188eu: make ReadEFuse return an int

drivers/staging/r8188eu/core/rtw_debug.c | 79 +++-
drivers/staging/r8188eu/core/rtw_efuse.c | 125 +++--
drivers/staging/r8188eu/core/rtw_io.c | 27 +-
drivers/staging/r8188eu/core/rtw_mp.c | 70 ++-
drivers/staging/r8188eu/core/rtw_mp_ioctl.c | 13 +-
drivers/staging/r8188eu/core/rtw_pwrctrl.c | 5 +-
drivers/staging/r8188eu/core/rtw_sreset.c | 9 +-
.../r8188eu/hal/Hal8188ERateAdaptive.c | 8 +-
drivers/staging/r8188eu/hal/HalPhyRf_8188e.c | 21 +-
drivers/staging/r8188eu/hal/HalPwrSeqCmd.c | 9 +-
drivers/staging/r8188eu/hal/hal_com.c | 23 +-
drivers/staging/r8188eu/hal/hal_intf.c | 6 +-
drivers/staging/r8188eu/hal/odm_interface.c | 12 +-
drivers/staging/r8188eu/hal/rtl8188e_cmd.c | 33 +-
drivers/staging/r8188eu/hal/rtl8188e_dm.c | 6 +-
.../staging/r8188eu/hal/rtl8188e_hal_init.c | 285 +++++++++---
drivers/staging/r8188eu/hal/rtl8188e_phycfg.c | 27 +-
drivers/staging/r8188eu/hal/rtl8188e_sreset.c | 22 +-
drivers/staging/r8188eu/hal/rtl8188eu_led.c | 18 +-
drivers/staging/r8188eu/hal/usb_halinit.c | 439 +++++++++++++++---
drivers/staging/r8188eu/hal/usb_ops_linux.c | 57 ++-
drivers/staging/r8188eu/include/hal_intf.h | 6 +-
.../staging/r8188eu/include/odm_interface.h | 6 +-
.../staging/r8188eu/include/rtl8188e_hal.h | 2 +-
drivers/staging/r8188eu/include/rtw_debug.h | 13 +
drivers/staging/r8188eu/include/rtw_efuse.h | 4 +-
drivers/staging/r8188eu/include/rtw_io.h | 18 +-
drivers/staging/r8188eu/include/rtw_mp.h | 2 -
drivers/staging/r8188eu/os_dep/ioctl_linux.c | 179 +++++--
drivers/staging/r8188eu/os_dep/usb_intf.c | 3 +-
30 files changed, 1138 insertions(+), 389 deletions(-)

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2.32.0