[PATCH 3.16 144/328] netfilter: nft_set: fix allocation size overflow in privsize callback.

Ben Hutchings
2018-12-09T22:18:11Z

From: Taehee Yoo <ap420073@gmail.com>

commit 4ef360dd6a65f6ef337645e1b65e744034754b19 upstream.

In order to determine allocation size of set, ->privsize is invoked.
At this point, both desc->size and size of each data structure of set
are used. desc->size means number of element that is given by user.
desc->size is u32 type. so that upperlimit of set element is 4294967295.
but return type of ->privsize is also u32. hence overflow can occurred.

test commands:
%nft add table ip filter
%nft add set ip filter hash1 { type ipv4_addr \; size 4294967295 \; }
%nft list ruleset

splat looks like:
[ 1239.202910] kasan: CONFIG_KASAN_INLINE enabled
[ 1239.208788] kasan: GPF could be caused by NULL-ptr deref or user memory access
[ 1239.217625] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 1239.219329] CPU: 0 PID: 1603 Comm: nft Not tainted 4.18.0-rc5+ #7
[ 1239.229091] RIP: 0010:nft_hash_walk+0x1d2/0x310 [nf_tables_set]
[ 1239.229091] Code: 84 d2 7f 10 4c 89 e7 89 44 24 38 e8 d8 5a 17 e0 8b 44 24 38 48 8d 7b 10 41 0f b6 0c 24 48 89 fa 48 89 fe 48 c1 ea 03 83 e6 07 <42> 0f b6 14 3a 40 38 f2 7f 1a 84 d2 74 16
[ 1239.229091] RSP: 0018:ffff8801118cf358 EFLAGS: 00010246
[ 1239.229091] RAX: 0000000000000000 RBX: 0000000000020400 RCX: 0000000000000001
[ 1239.229091] RDX: 0000000000004082 RSI: 0000000000000000 RDI: 0000000000020410
[ 1239.229091] RBP: ffff880114d5a988 R08: 0000000000007e94 R09: ffff880114dd8030
[ 1239.229091] R10: ffff880114d5a988 R11: ffffed00229bb006 R12: ffff8801118cf4d0
[ 1239.229091] R13: ffff8801118cf4d8 R14: 0000000000000000 R15: dffffc0000000000
[ 1239.229091] FS: 00007f5a8fe0b700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000
[ 1239.229091] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1239.229091] CR2: 00007f5a8ecc27b0 CR3: 000000010608e000 CR4: 00000000001006f0
[ 1239.229091] Call Trace:
[ 1239.229091] ? nft_hash_remove+0xf0/0xf0 [nf_tables_set]
[ 1239.229091] ? memset+0x1f/0x40
[ 1239.229091] ? __nla_reserve+0x9f/0xb0
[ 1239.229091] ? memcpy+0x34/0x50
[ 1239.229091] nf_tables_dump_set+0x9a1/0xda0 [nf_tables]
[ 1239.229091] ? __kmalloc_reserve.isra.29+0x2e/0xa0
[ 1239.229091] ? nft_chain_hash_obj+0x630/0x630 [nf_tables]
[ 1239.229091] ? nf_tables_commit+0x2c60/0x2c60 [nf_tables]
[ 1239.229091] netlink_dump+0x470/0xa20
[ 1239.229091] __netlink_dump_start+0x5ae/0x690
[ 1239.229091] nft_netlink_dump_start_rcu+0xd1/0x160 [nf_tables]
[ 1239.229091] nf_tables_getsetelem+0x2e5/0x4b0 [nf_tables]
[ 1239.229091] ? nft_get_set_elem+0x440/0x440 [nf_tables]
[ 1239.229091] ? nft_chain_hash_obj+0x630/0x630 [nf_tables]
[ 1239.229091] ? nf_tables_dump_obj_done+0x70/0x70 [nf_tables]
[ 1239.229091] ? nla_parse+0xab/0x230
[ 1239.229091] ? nft_get_set_elem+0x440/0x440 [nf_tables]
[ 1239.229091] nfnetlink_rcv_msg+0x7f0/0xab0 [nfnetlink]
[ 1239.229091] ? nfnetlink_bind+0x1d0/0x1d0 [nfnetlink]
[ 1239.229091] ? debug_show_all_locks+0x290/0x290
[ 1239.229091] ? sched_clock_cpu+0x132/0x170
[ 1239.229091] ? find_held_lock+0x39/0x1b0
[ 1239.229091] ? sched_clock_local+0x10d/0x130
[ 1239.229091] netlink_rcv_skb+0x211/0x320
[ 1239.229091] ? nfnetlink_bind+0x1d0/0x1d0 [nfnetlink]
[ 1239.229091] ? netlink_ack+0x7b0/0x7b0
[ 1239.229091] ? ns_capable_common+0x6e/0x110
[ 1239.229091] nfnetlink_rcv+0x2d1/0x310 [nfnetlink]
[ 1239.229091] ? nfnetlink_rcv_batch+0x10f0/0x10f0 [nfnetlink]
[ 1239.229091] ? netlink_deliver_tap+0x829/0x930
[ 1239.229091] ? lock_acquire+0x265/0x2e0
[ 1239.229091] netlink_unicast+0x406/0x520
[ 1239.509725] ? netlink_attachskb+0x5b0/0x5b0
[ 1239.509725] ? find_held_lock+0x39/0x1b0
[ 1239.509725] netlink_sendmsg+0x987/0xa20
[ 1239.509725] ? netlink_unicast+0x520/0x520
[ 1239.509725] ? _copy_from_user+0xa9/0xc0
[ 1239.509725] __sys_sendto+0x21a/0x2c0
[ 1239.509725] ? __ia32_sys_getpeername+0xa0/0xa0
[ 1239.509725] ? retint_kernel+0x10/0x10
[ 1239.509725] ? sched_clock_cpu+0x132/0x170
[ 1239.509725] ? find_held_lock+0x39/0x1b0
[ 1239.509725] ? lock_downgrade+0x540/0x540
[ 1239.509725] ? up_read+0x1c/0x100
[ 1239.509725] ? __do_page_fault+0x763/0x970
[ 1239.509725] ? retint_user+0x18/0x18
[ 1239.509725] __x64_sys_sendto+0x177/0x180
[ 1239.509725] do_syscall_64+0xaa/0x360
[ 1239.509725] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 1239.509725] RIP: 0033:0x7f5a8f468e03
[ 1239.509725] Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb d0 0f 1f 84 00 00 00 00 00 83 3d 49 c9 2b 00 00 75 13 49 89 ca b8 2c 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8
[ 1239.509725] RSP: 002b:00007ffd78d0b778 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
[ 1239.509725] RAX: ffffffffffffffda RBX: 00007ffd78d0c890 RCX: 00007f5a8f468e03
[ 1239.509725] RDX: 0000000000000034 RSI: 00007ffd78d0b7e0 RDI: 0000000000000003
[ 1239.509725] RBP: 00007ffd78d0b7d0 R08: 00007f5a8f15c160 R09: 000000000000000c
[ 1239.509725] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd78d0b7e0
[ 1239.509725] R13: 0000000000000034 R14: 00007f5a8f9aff60 R15: 00005648040094b0
[ 1239.509725] Modules linked in: nf_tables_set nf_tables nfnetlink ip_tables x_tables
[ 1239.670713] ---[ end trace 39375adcda140f11 ]---
[ 1239.676016] RIP: 0010:nft_hash_walk+0x1d2/0x310 [nf_tables_set]
[ 1239.682834] Code: 84 d2 7f 10 4c 89 e7 89 44 24 38 e8 d8 5a 17 e0 8b 44 24 38 48 8d 7b 10 41 0f b6 0c 24 48 89 fa 48 89 fe 48 c1 ea 03 83 e6 07 <42> 0f b6 14 3a 40 38 f2 7f 1a 84 d2 74 16
[ 1239.705108] RSP: 0018:ffff8801118cf358 EFLAGS: 00010246
[ 1239.711115] RAX: 0000000000000000 RBX: 0000000000020400 RCX: 0000000000000001
[ 1239.719269] RDX: 0000000000004082 RSI: 0000000000000000 RDI: 0000000000020410
[ 1239.727401] RBP: ffff880114d5a988 R08: 0000000000007e94 R09: ffff880114dd8030
[ 1239.735530] R10: ffff880114d5a988 R11: ffffed00229bb006 R12: ffff8801118cf4d0
[ 1239.743658] R13: ffff8801118cf4d8 R14: 0000000000000000 R15: dffffc0000000000
[ 1239.751785] FS: 00007f5a8fe0b700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000
[ 1239.760993] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1239.767560] CR2: 00007f5a8ecc27b0 CR3: 000000010608e000 CR4: 00000000001006f0
[ 1239.775679] Kernel panic - not syncing: Fatal exception
[ 1239.776630] Kernel Offset: 0x1f000000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[ 1239.776630] Rebooting in 5 seconds..

Fixes: 20a69341f2d0 ("netfilter: nf_tables: add netlink set API")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
[bwh: Backported to 3.16:
- Drop changes to nft_rhash_privsize() and in nft_set_bitmap.c
- Adjust filenames]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
--- a/include/net/netfilter/nf_tables.h
+++ b/include/net/netfilter/nf_tables.h
@@ -183,7 +183,7 @@ enum nft_set_class {
* @class: lookup performance class
*/
struct nft_set_estimate {
- unsigned int size;
+ u64 size;
enum nft_set_class class;
};

@@ -215,7 +215,7 @@ struct nft_set_ops {
const struct nft_set *set,
struct nft_set_iter *iter);

- unsigned int (*privsize)(const struct nlattr * const nla[]);
+ u64 (*privsize)(const struct nlattr * const nla[]);
bool (*estimate)(const struct nft_set_desc *desc,
u32 features,
struct nft_set_estimate *est);
--- a/net/netfilter/nf_tables_api.c
+++ b/net/netfilter/nf_tables_api.c
@@ -2519,7 +2519,7 @@ static int nf_tables_newset(struct sock
struct nft_set *set;
struct nft_ctx ctx;
char name[IFNAMSIZ];
- unsigned int size;
+ u64 size;
bool create;
u32 ktype, dtype, flags, policy;
struct nft_set_desc desc;
--- a/net/netfilter/nft_hash.c
+++ b/net/netfilter/nft_hash.c
@@ -327,7 +327,7 @@ cont:
}
}

-static unsigned int nft_hash_privsize(const struct nlattr * const nla[])
+static u64 nft_hash_privsize(const struct nlattr * const nla[])
{
return sizeof(struct nft_hash);
}
--- a/net/netfilter/nft_rbtree.c
+++ b/net/netfilter/nft_rbtree.c
@@ -211,7 +211,7 @@ cont:
spin_unlock_bh(&nft_rbtree_lock);
}

-static unsigned int nft_rbtree_privsize(const struct nlattr * const nla[])
+static u64 nft_rbtree_privsize(const struct nlattr * const nla[])
{
return sizeof(struct nft_rbtree);
}