| Message ID | 20250517165713.935384-1-xin@zytor.com |
|---|---|
| State | New |
| Headers | show |
| Series | None | expand |
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index 7f9ded1bc707..26bbaf4b7330 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -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); }
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(). Fixes: d815da84fdd0 ("x86/msr: Change the function type of native_read_msr_safe()" Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/xen-devel/aBxNI_Q0-MhtBSZG@stanley.mountain/ Signed-off-by: Xin Li (Intel) <xin@zytor.com> --- Change in v1A: *) Drop setting err to 0 in xen_do_read_msr() initially and set err to 0 in all callers (Jürgen Groß). --- arch/x86/xen/enlighten_pv.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)