linux/drivers/hsi
Nathan Chancellor 913a144164 HSI: ssi_protocol: Fix return type of ssip_pn_xmit()
With clang's kernel control flow integrity (kCFI, CONFIG_CFI_CLANG),
indirect call targets are validated against the expected function
pointer prototype to make sure the call target is valid to help mitigate
ROP attacks. If they are not identical, there is a failure at run time,
which manifests as either a kernel panic or thread getting killed. A
proposed warning in clang aims to catch these at compile time, which
reveals:

  drivers/hsi/clients/ssi_protocol.c:1053:20: error: incompatible function pointer types initializing 'netdev_tx_t (*)(struct sk_buff *, struct net_device *)' (aka 'enum netdev_tx (*)(struct sk_buff *, struct net_device *)') with an expression of type 'int (struct sk_buff *, struct net_device *)' [-Werror,-Wincompatible-function-pointer-types-strict]
          .ndo_start_xmit = ssip_pn_xmit,
                            ^~~~~~~~~~~~
  1 error generated.

->ndo_start_xmit() in 'struct net_device_ops' expects a return type of
'netdev_tx_t', not 'int'. Adjust the return type of ssip_pn_xmit() to
match the prototype's to resolve the warning and CFI failure.
Additionally, use the enum 'NETDEV_TX_OK' instead of a raw '0' for the
return value of ssip_pn_xmit().

Link: https://github.com/ClangBuiltLinux/linux/issues/1750
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
2022-11-14 21:43:37 +01:00
..
clients HSI: ssi_protocol: Fix return type of ssip_pn_xmit() 2022-11-14 21:43:37 +01:00
controllers HSI: omap_ssi_port: Fix dma_map_sg error check 2022-08-29 18:08:48 +02:00
hsi_boardinfo.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336 2019-06-05 17:37:07 +02:00
hsi_core.c HSI: core: Fix return freed object in hsi_new_client 2021-11-26 00:27:06 +01:00
hsi_core.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 336 2019-06-05 17:37:07 +02:00
Kconfig treewide: replace '---help---' in Kconfig files with 'help' 2020-06-14 01:57:21 +09:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00