Dave Jones reported that KASan detected out of bounds access in hash:net*
types:
[ 23.139532] ==================================================================
[ 23.146130] BUG: KASan: out of bounds access in hash_net4_add_cidr+0x1db/0x220 at addr ffff8800d4844b58
[ 23.152937] Write of size 4 by task ipset/457
[ 23.159742] =============================================================================
[ 23.166672] BUG kmalloc-512 (Not tainted): kasan: bad access detected
[ 23.173641] -----------------------------------------------------------------------------
[ 23.194668] INFO: Allocated in hash_net_create+0x16a/0x470 age=7 cpu=1 pid=456
[ 23.201836] __slab_alloc.constprop.66+0x554/0x620
[ 23.208994] __kmalloc+0x2f2/0x360
[ 23.216105] hash_net_create+0x16a/0x470
[ 23.223238] ip_set_create+0x3e6/0x740
[ 23.230343] nfnetlink_rcv_msg+0x599/0x640
[ 23.237454] netlink_rcv_skb+0x14f/0x190
[ 23.244533] nfnetlink_rcv+0x3f6/0x790
[ 23.251579] netlink_unicast+0x272/0x390
[ 23.258573] netlink_sendmsg+0x5a1/0xa50
[ 23.265485] SYSC_sendto+0x1da/0x2c0
[ 23.272364] SyS_sendto+0xe/0x10
[ 23.279168] entry_SYSCALL_64_fastpath+0x12/0x6f
The bug is fixed in the patch and the testsuite is extended in ipset
to check cidr handling more thoroughly.
Signed-off-by: Jozsef Kadlecsik <kadlec@xxxxxxxxxxxxxxxxx>
---
net/netfilter/ipset/ip_set_hash_gen.h | 12 ++++++++----
1 file changed, 8 insertions(+), 4 deletions(-)
diff --git a/net/netfilter/ipset/ip_set_hash_gen.h b/net/netfilter/ipset/ip_set_hash_gen.h
index afe905c..691b54f 100644
--- a/net/netfilter/ipset/ip_set_hash_gen.h
+++ b/net/netfilter/ipset/ip_set_hash_gen.h
@@ -152,9 +152,13 @@ htable_bits(u32 hashsize)
#define SET_HOST_MASK(family) (family == AF_INET ? 32 : 128)
#ifdef IP_SET_HASH_WITH_NET0
+/* cidr from 0 to SET_HOST_MASK() value and c = cidr + 1 */
#define NLEN(family) (SET_HOST_MASK(family) + 1)
+#define CIDR_POS(c) ((c) - 1)
#else
+/* cidr from 1 to SET_HOST_MASK() value and c = cidr + 1 */
#define NLEN(family) SET_HOST_MASK(family)
+#define CIDR_POS(c) ((c) - 2)
#endif
#else
@@ -305,7 +309,7 @@ mtype_add_cidr(struct htype *h, u8 cidr, u8 nets_length, u8 n)
} else if (h->nets[i].cidr[n] < cidr) {
j = i;
} else if (h->nets[i].cidr[n] == cidr) {
- h->nets[cidr - 1].nets[n]++;
+ h->nets[CIDR_POS(cidr)].nets[n]++;
return;
}
}
@@ -314,7 +318,7 @@ mtype_add_cidr(struct htype *h, u8 cidr, u8 nets_length, u8 n)
h->nets[i].cidr[n] = h->nets[i - 1].cidr[n];
}
h->nets[i].cidr[n] = cidr;
- h->nets[cidr - 1].nets[n] = 1;
+ h->nets[CIDR_POS(cidr)].nets[n] = 1;
}
static void
@@ -325,8 +329,8 @@ mtype_del_cidr(struct htype *h, u8 cidr, u8 nets_length, u8 n)
for (i = 0; i < nets_length; i++) {
if (h->nets[i].cidr[n] != cidr)
continue;
- h->nets[cidr - 1].nets[n]--;
- if (h->nets[cidr - 1].nets[n] > 0)
+ h->nets[CIDR_POS(cidr)].nets[n]--;
+ if (h->nets[CIDR_POS(cidr)].nets[n] > 0)
return;
for (j = i; j < net_end && h->nets[j].cidr[n]; j++)
h->nets[j].cidr[n] = h->nets[j + 1].cidr[n];
--
1.8.5.1
--
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