Commit 2dd30718 authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by David S. Miller
Browse files

net: wwan: t7xx: Add __counted_by for struct t7xx_fsm_event and use struct_size() 



Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time via CONFIG_UBSAN_BOUNDS (for
array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

While there, use struct_size() helper, instead of the open-coded
version, to calculate the size for the allocation of the whole
flexible structure, including of course, the flexible-array member.

This code was found with the help of Coccinelle, and audited and
fixed manually.

Signed-off-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 13266ad9

drivers/net/wwan/t7xx/t7xx_state_monitor.c

+2 −1
Original line number Diff line number Diff line
@@ -445,7 +445,8 @@ int t7xx_fsm_append_event(struct t7xx_fsm_ctl *ctl, enum t7xx_fsm_event_state ev 
		return -EINVAL;

	}



	event = kmalloc(sizeof(*event) + length, in_interrupt() ? GFP_ATOMIC : GFP_KERNEL);

	event = kmalloc(struct_size(event, data, length),

			in_interrupt() ? GFP_ATOMIC : GFP_KERNEL);

	if (!event)

		return -ENOMEM;

drivers/net/wwan/t7xx/t7xx_state_monitor.h

+1 −1
Original line number Diff line number Diff line
@@ -102,7 +102,7 @@ struct t7xx_fsm_event { 
	struct list_head	entry;

	enum t7xx_fsm_event_state event_id;

	unsigned int		length;

	unsigned char		data[];

	unsigned char		data[] __counted_by(length);

};



struct t7xx_fsm_command {