libceph: replace BUG_ON with bounds check for map->max_osd

OSD indexes come from untrusted network packets. Boundary checks are
added to validate these against map->max_osd.

[ idryomov: drop BUG_ON in ceph_get_primary_affinity(), minor cosmetic
  edits ]

Cc: stable@vger.kernel.org
Signed-off-by: ziming zhang <ezrakiez@gmail.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

Author: ziming zhang

net/ceph/osdmap.c

@@ -1504,8 +1504,6 @@ static int decode_new_primary_temp(void **p, void *end,
 
 u32 ceph_get_primary_affinity(struct ceph_osdmap *map, int osd)
 {
-	BUG_ON(osd >= map->max_osd);
-
 	if (!map->osd_primary_affinity)
 		return CEPH_OSD_DEFAULT_PRIMARY_AFFINITY;
 
@@ -1514,8 +1512,6 @@ u32 ceph_get_primary_affinity(struct ceph_osdmap *map, int osd)
 
 static int set_primary_affinity(struct ceph_osdmap *map, int osd, u32 aff)
 {
-	BUG_ON(osd >= map->max_osd);
-
 	if (!map->osd_primary_affinity) {
 		int i;
 
@@ -1577,6 +1573,8 @@ static int decode_new_primary_affinity(void **p, void *end,
 
 		ceph_decode_32_safe(p, end, osd, e_inval);
 		ceph_decode_32_safe(p, end, aff, e_inval);
+		if (osd >= map->max_osd)
+			goto e_inval;
 
 		ret = set_primary_affinity(map, osd, aff);
 		if (ret)
@@ -1879,7 +1877,9 @@ static int decode_new_up_state_weight(void **p, void *end, u8 struct_v,
 		ceph_decode_need(p, end, 2*sizeof(u32), e_inval);
 		osd = ceph_decode_32(p);
 		w = ceph_decode_32(p);
-		BUG_ON(osd >= map->max_osd);
+		if (osd >= map->max_osd)
+			goto e_inval;
+
 		osdmap_info(map, "osd%d weight 0x%x %s\n", osd, w,
 			    w == CEPH_OSD_IN ? "(in)" :
 			    (w == CEPH_OSD_OUT ? "(out)" : ""));
@@ -1905,13 +1905,15 @@ static int decode_new_up_state_weight(void **p, void *end, u8 struct_v,
 		u32 xorstate;
 
 		osd = ceph_decode_32(p);
+		if (osd >= map->max_osd)
+			goto e_inval;
+
 		if (struct_v >= 5)
 			xorstate = ceph_decode_32(p);
 		else
 			xorstate = ceph_decode_8(p);
 		if (xorstate == 0)
 			xorstate = CEPH_OSD_UP;
-		BUG_ON(osd >= map->max_osd);
 		if ((map->osd_state[osd] & CEPH_OSD_UP) &&
 		    (xorstate & CEPH_OSD_UP))
 			osdmap_info(map, "osd%d down\n", osd);
@@ -1937,7 +1939,9 @@ static int decode_new_up_state_weight(void **p, void *end, u8 struct_v,
 		struct ceph_entity_addr addr;
 
 		osd = ceph_decode_32(p);
-		BUG_ON(osd >= map->max_osd);
+		if (osd >= map->max_osd)
+			goto e_inval;
+
 		if (struct_v >= 7)
 			ret = ceph_decode_entity_addrvec(p, end, msgr2, &addr);
 		else