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authorDan Carpenter <error27@gmail.com>2011-06-03 07:45:28 +0300
committerAndi Kleen <ak@linux.intel.com>2011-08-01 13:54:55 -0700
commitab0cc25a4b0367227df10f18c98db96af2db1dc0 (patch)
treed21c8aa160378b9757e6edcaba930667cef49842
parentff7cb9c3fe433028969fe28b5a542a0477b252b3 (diff)
xen: off by one errors in multicalls.c
commit f124c6ae59e193705c9ddac57684d50006d710e6 upstream. 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@gmail.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andi Kleen <ak@linux.intel.com>
-rw-r--r--arch/x86/xen/multicalls.c12
1 files changed, 6 insertions, 6 deletions
diff --git a/arch/x86/xen/multicalls.c b/arch/x86/xen/multicalls.c
index 8bff7e7c290b..1b2b73ff0a6e 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;
}