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staging/rtl8192u: Prefer kcalloc over open coded arithmetic 

As noted in the "Deprecated Interfaces, Language Features, Attributes,
and Conventions" documentation [1], size calculations (especially
multiplication) should not be performed in memory allocator (or similar)
function arguments due to the risk of them overflowing. This could lead
to values wrapping around and a smaller allocation being made than the
caller was expecting. Using those allocations could lead to linear
overflows of heap memory and other misbehaviors.

In this case these aren't actually dynamic sizes: both sides of the
multiplication are constant values. However it is best to refactor these
anyway, just to keep the open-coded math idiom out of code.

So, use the purpose specific kcalloc() function instead of the argument
size * count in the kzalloc() function.

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#open-coded-arithmetic-in-allocator-arguments

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Len Baker <len.baker@gmx.com>
Link: https://lore.kernel.org/r/20210824090039.GA7999@titan
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Len Baker 2021-08-24 11:00:39 +02:00 committed by Greg Kroah-Hartman
parent c4b30776bf
commit 07e7f36da8
1 changed files with 3 additions and 3 deletions
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6
drivers/staging/rtl8192u/r819xU_phy.c
View File

@ -1195,17 +1195,17 @@ static u8 rtl8192_phy_SwChnlStepByStep(struct net_device *dev, u8 channel,
u8 e_rfpath;
bool ret;
pre_cmd = kzalloc(sizeof(*pre_cmd) * MAX_PRECMD_CNT, GFP_KERNEL);
pre_cmd = kcalloc(MAX_PRECMD_CNT, sizeof(*pre_cmd), GFP_KERNEL);
if (!pre_cmd)
return false;
post_cmd = kzalloc(sizeof(*post_cmd) * MAX_POSTCMD_CNT, GFP_KERNEL);
post_cmd = kcalloc(MAX_POSTCMD_CNT, sizeof(*post_cmd), GFP_KERNEL);
if (!post_cmd) {
kfree(pre_cmd);
return false;
}
rf_cmd = kzalloc(sizeof(*rf_cmd) * MAX_RFDEPENDCMD_CNT, GFP_KERNEL);
rf_cmd = kcalloc(MAX_RFDEPENDCMD_CNT, sizeof(*rf_cmd), GFP_KERNEL);
if (!rf_cmd) {
kfree(pre_cmd);
kfree(post_cmd);