b->args[] has MC_ARGS elements, so the comparison here should be
">=" instead of ">". Otherwise we read past the end of the array
one space.
Signed-off-by: Dan Carpenter <error27@xxxxxxxxx>
---
This is a static checker patch and I haven't tested it. Please
review carefully.
diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c
index 8bff7e7..1b2b73f 100644
--- a/arch/x86/xen/multicalls.c
+++ b/arch/x86/xen/multicalls.c
@@ -189,10 +189,10 @@ struct multicall_space __xen_mc_entry(size_t args)
unsigned argidx = roundup(b->argidx, sizeof(u64));
BUG_ON(preemptible());
- BUG_ON(b->argidx > MC_ARGS);
+ BUG_ON(b->argidx >= MC_ARGS);
if (b->mcidx == MC_BATCH ||
- (argidx + args) > MC_ARGS) {
+ (argidx + args) >= MC_ARGS) {
mc_stats_flush(b->mcidx == MC_BATCH ? FL_SLOTS : FL_ARGS);
xen_mc_flush();
argidx = roundup(b->argidx, sizeof(u64));
@@ -206,7 +206,7 @@ struct multicall_space __xen_mc_entry(size_t args)
ret.args = &b->args[argidx];
b->argidx = argidx + args;
- BUG_ON(b->argidx > MC_ARGS);
+ BUG_ON(b->argidx >= MC_ARGS);
return ret;
}
@@ -216,7 +216,7 @@ struct multicall_space xen_mc_extend_args(unsigned long op, size_t size)
struct multicall_space ret = { NULL, NULL };
BUG_ON(preemptible());
- BUG_ON(b->argidx > MC_ARGS);
+ BUG_ON(b->argidx >= MC_ARGS);
if (b->mcidx == 0)
return ret;
@@ -224,14 +224,14 @@ struct multicall_space xen_mc_extend_args(unsigned long op, size_t size)
if (b->entries[b->mcidx - 1].op != op)
return ret;
- if ((b->argidx + size) > MC_ARGS)
+ if ((b->argidx + size) >= MC_ARGS)
return ret;
ret.mc = &b->entries[b->mcidx - 1];
ret.args = &b->args[b->argidx];
b->argidx += size;
- BUG_ON(b->argidx > MC_ARGS);
+ BUG_ON(b->argidx >= MC_ARGS);
return ret;
}
--
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