Re: [PATCH wireless-next 0/6] Consolidate Michael MIC code into mac80211

[Jeff Johnson]

On 4/4/2026 10:27 PM, Eric Biggers wrote:
> Michael MIC is an inherently weak algorithm that is specific to WPA
> TKIP, which itself was an interim security solution to replace the
> broken WEP standard.
> 
> Currently, the primary implementation of Michael MIC in the kernel is
> the one in the mac80211 module.  But there's also a duplicate
> implementation in crypto/michael_mic.c which is exposed via the
> crypto_shash API.  It's used only by a few wireless drivers.
> 
> Seeing as Michael MIC is specific to WPA TKIP and should never be used
> elsewhere, this series migrates those few drivers to the mac80211
> implementation of Michael MIC, then removes the crypto implementation of
> Michael MIC.  This consolidates duplicate code and prevents other kernel
> subsystems from accidentally using this insecure algorithm.
> 
> This series is targeting wireless-next.
> 
> Eric Biggers (6):
>   wifi: mac80211: Export michael_mic()
>   wifi: ath11k: Use michael_mic() from mac80211
>   wifi: ath12k: Use michael_mic() from mac80211
>   wifi: ipw2x00: Depend on MAC80211
>   wifi: ipw2x00: Use michael_mic() from mac80211
>   crypto: Remove michael_mic from crypto_shash API
> 
>  arch/arm/configs/omap2plus_defconfig          |   1 -
>  arch/arm/configs/spitz_defconfig              |   1 -
>  arch/arm64/configs/defconfig                  |   1 -
>  arch/m68k/configs/amiga_defconfig             |   1 -
>  arch/m68k/configs/apollo_defconfig            |   1 -
>  arch/m68k/configs/atari_defconfig             |   1 -
>  arch/m68k/configs/bvme6000_defconfig          |   1 -
>  arch/m68k/configs/hp300_defconfig             |   1 -
>  arch/m68k/configs/mac_defconfig               |   1 -
>  arch/m68k/configs/multi_defconfig             |   1 -
>  arch/m68k/configs/mvme147_defconfig           |   1 -
>  arch/m68k/configs/mvme16x_defconfig           |   1 -
>  arch/m68k/configs/q40_defconfig               |   1 -
>  arch/m68k/configs/sun3_defconfig              |   1 -
>  arch/m68k/configs/sun3x_defconfig             |   1 -
>  arch/mips/configs/bigsur_defconfig            |   1 -
>  arch/mips/configs/decstation_64_defconfig     |   1 -
>  arch/mips/configs/decstation_defconfig        |   1 -
>  arch/mips/configs/decstation_r4k_defconfig    |   1 -
>  arch/mips/configs/gpr_defconfig               |   1 -
>  arch/mips/configs/ip32_defconfig              |   1 -
>  arch/mips/configs/lemote2f_defconfig          |   1 -
>  arch/mips/configs/malta_qemu_32r6_defconfig   |   1 -
>  arch/mips/configs/maltaaprp_defconfig         |   1 -
>  arch/mips/configs/maltasmvp_defconfig         |   1 -
>  arch/mips/configs/maltasmvp_eva_defconfig     |   1 -
>  arch/mips/configs/maltaup_defconfig           |   1 -
>  arch/mips/configs/mtx1_defconfig              |   1 -
>  arch/mips/configs/rm200_defconfig             |   1 -
>  arch/mips/configs/sb1250_swarm_defconfig      |   1 -
>  arch/parisc/configs/generic-32bit_defconfig   |   1 -
>  arch/parisc/configs/generic-64bit_defconfig   |   1 -
>  arch/powerpc/configs/g5_defconfig             |   1 -
>  arch/powerpc/configs/linkstation_defconfig    |   1 -
>  arch/powerpc/configs/mvme5100_defconfig       |   1 -
>  arch/powerpc/configs/powernv_defconfig        |   1 -
>  arch/powerpc/configs/ppc64_defconfig          |   1 -
>  arch/powerpc/configs/ppc64e_defconfig         |   1 -
>  arch/powerpc/configs/ppc6xx_defconfig         |   1 -
>  arch/powerpc/configs/ps3_defconfig            |   1 -
>  arch/s390/configs/debug_defconfig             |   1 -
>  arch/s390/configs/defconfig                   |   1 -
>  arch/sh/configs/sh2007_defconfig              |   1 -
>  arch/sh/configs/titan_defconfig               |   1 -
>  arch/sh/configs/ul2_defconfig                 |   1 -
>  arch/sparc/configs/sparc32_defconfig          |   1 -
>  arch/sparc/configs/sparc64_defconfig          |   1 -
>  crypto/Kconfig                                |  12 --
>  crypto/Makefile                               |   1 -
>  crypto/michael_mic.c                          | 176 ------------------
>  crypto/tcrypt.c                               |   4 -
>  crypto/testmgr.c                              |   6 -
>  crypto/testmgr.h                              |  50 -----
>  drivers/net/wireless/ath/ath11k/Kconfig       |   1 -
>  drivers/net/wireless/ath/ath11k/dp.c          |   2 -
>  drivers/net/wireless/ath/ath11k/dp_rx.c       |  60 +-----
>  drivers/net/wireless/ath/ath11k/peer.h        |   1 -
>  drivers/net/wireless/ath/ath12k/Kconfig       |   1 -
>  drivers/net/wireless/ath/ath12k/dp.c          |   2 -
>  drivers/net/wireless/ath/ath12k/dp_peer.h     |   1 -
>  drivers/net/wireless/ath/ath12k/dp_rx.c       |  55 +-----
>  drivers/net/wireless/ath/ath12k/dp_rx.h       |   4 -
>  drivers/net/wireless/ath/ath12k/wifi7/dp_rx.c |   7 +-
>  drivers/net/wireless/intel/ipw2x00/Kconfig    |   7 +-
>  .../intel/ipw2x00/libipw_crypto_tkip.c        | 120 +-----------
>  include/linux/ieee80211.h                     |   5 +
>  net/mac80211/michael.c                        |   5 +-
>  net/mac80211/michael.h                        |  22 ---
>  net/mac80211/wpa.c                            |   1 -
>  69 files changed, 32 insertions(+), 558 deletions(-)
>  delete mode 100644 crypto/michael_mic.c
>  delete mode 100644 net/mac80211/michael.h
> 
> 
> base-commit: dbd94b9831bc52a1efb7ff3de841ffc3457428ce

Note this series does not bisect cleanly since the introduction of the export
in 1/6 causes build failures:

../drivers/net/wireless/intel/ipw2x00/libipw_crypto_tkip.c:467:12: error: conflicting types for 'michael_mic'; have 'int(struct crypto_shash *, u8 *, u8 *, u8 *, size_t,  u8 *)' {aka 'int(struct crypto_shash *, unsigned char *, unsigned char *, unsigned char *, long unsigned int,  unsigned char *)'}
  467 | static int michael_mic(struct crypto_shash *tfm_michael, u8 *key, u8 *hdr,
      |            ^~~~~~~~~~~
In file included from ../drivers/net/wireless/intel/ipw2x00/libipw_crypto_tkip.c:25:
../include/linux/ieee80211.h:1926:6: note: previous declaration of 'michael_mic' with type 'void(const u8 *, struct ieee80211_hdr *, const u8 *, size_t,  u8 *)' {aka 'void(const unsigned char *, struct ieee80211_hdr *, const unsigned char *, long unsigned int,  unsigned char *)'}
 1926 | void michael_mic(const u8 *key, struct ieee80211_hdr *hdr,
      |      ^~~~~~~~~~~