Commit e95534e1 authored by Xin Li (Intel)'s avatar Xin Li (Intel) Committed by Ingo Molnar
Browse files

x86/xen/msr: Fix uninitialized variable 'err' 

xen_read_msr_safe() currently passes an uninitialized argument 'err' to
xen_do_read_msr(). But as xen_do_read_msr() may not set the argument,
xen_read_msr_safe() could return err with an unpredictable value.

To ensure correctness, initialize err to 0 (representing success)
in xen_read_msr_safe().

Do the same in xen_read_msr(), even err is not used after being passed
to xen_do_read_msr().

Closes: https://lore.kernel.org/xen-devel/aBxNI_Q0-MhtBSZG@stanley.mountain/


Reported-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: default avatarXin Li (Intel) <xin@zytor.com>
Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
Reviewed-by: default avatarJuergen Gross <jgross@suse.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Link: https://lore.kernel.org/r/20250517165713.935384-1-xin@zytor.com
parent 9220aa8a

arch/x86/xen/enlighten_pv.c

+2 −2
Original line number Diff line number Diff line
@@ -1162,7 +1162,7 @@ static void xen_do_write_msr(u32 msr, u64 val, int *err) 


static int xen_read_msr_safe(u32 msr, u64 *val)

{

	int err;

	int err = 0;



	*val = xen_do_read_msr(msr, &err);

	return err;
@@ -1179,7 +1179,7 @@ static int xen_write_msr_safe(u32 msr, u64 val) 


static u64 xen_read_msr(u32 msr)

{

	int err;

	int err = 0;



	return xen_do_read_msr(msr, xen_msr_safe ? &err : NULL);

}