From: Pablo Neira Ayuso pablo@netfilter.org
[ Upstream commit ad9f151e560b016b6ad3280b48e42fa11e1a5440 ]
nft_set_elem_expr_alloc() needs an initialized set if expression sets on the NFT_EXPR_GC flag. Move set fields initialization before expression setup.
[4512935.019450] ================================================================== [4512935.019456] BUG: KASAN: null-ptr-deref in nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables] [4512935.019487] Read of size 8 at addr 0000000000000070 by task nft/23532 [4512935.019494] CPU: 1 PID: 23532 Comm: nft Not tainted 5.12.0-rc4+ #48 [...] [4512935.019502] Call Trace: [4512935.019505] dump_stack+0x89/0xb4 [4512935.019512] ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables] [4512935.019536] ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables] [4512935.019560] kasan_report.cold.12+0x5f/0xd8 [4512935.019566] ? nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables] [4512935.019590] nft_set_elem_expr_alloc+0x84/0xd0 [nf_tables] [4512935.019615] nf_tables_newset+0xc7f/0x1460 [nf_tables]
Reported-by: syzbot+ce96ca2b1d0b37c6422d@syzkaller.appspotmail.com Fixes: 65038428b2c6 ("netfilter: nf_tables: allow to specify stateful expression in set definition") Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin sashal@kernel.org --- net/netfilter/nf_tables_api.c | 83 ++++++++++++++++++----------------- 1 file changed, 42 insertions(+), 41 deletions(-)
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 31016c144c48..9d5ea2352965 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -4317,13 +4317,44 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk, err = nf_tables_set_alloc_name(&ctx, set, name); kfree(name); if (err < 0) - goto err_set_alloc_name; + goto err_set_name; + + udata = NULL; + if (udlen) { + udata = set->data + size; + nla_memcpy(udata, nla[NFTA_SET_USERDATA], udlen); + } + + INIT_LIST_HEAD(&set->bindings); + set->table = table; + write_pnet(&set->net, net); + set->ops = ops; + set->ktype = ktype; + set->klen = desc.klen; + set->dtype = dtype; + set->objtype = objtype; + set->dlen = desc.dlen; + set->flags = flags; + set->size = desc.size; + set->policy = policy; + set->udlen = udlen; + set->udata = udata; + set->timeout = timeout; + set->gc_int = gc_int; + + set->field_count = desc.field_count; + for (i = 0; i < desc.field_count; i++) + set->field_len[i] = desc.field_len[i]; + + err = ops->init(set, &desc, nla); + if (err < 0) + goto err_set_init;
if (nla[NFTA_SET_EXPR]) { expr = nft_set_elem_expr_alloc(&ctx, set, nla[NFTA_SET_EXPR]); if (IS_ERR(expr)) { err = PTR_ERR(expr); - goto err_set_alloc_name; + goto err_set_expr_alloc; } set->exprs[0] = expr; set->num_exprs++; @@ -4334,74 +4365,44 @@ static int nf_tables_newset(struct net *net, struct sock *nlsk,
if (!(flags & NFT_SET_EXPR)) { err = -EINVAL; - goto err_set_alloc_name; + goto err_set_expr_alloc; } i = 0; nla_for_each_nested(tmp, nla[NFTA_SET_EXPRESSIONS], left) { if (i == NFT_SET_EXPR_MAX) { err = -E2BIG; - goto err_set_init; + goto err_set_expr_alloc; } if (nla_type(tmp) != NFTA_LIST_ELEM) { err = -EINVAL; - goto err_set_init; + goto err_set_expr_alloc; } expr = nft_set_elem_expr_alloc(&ctx, set, tmp); if (IS_ERR(expr)) { err = PTR_ERR(expr); - goto err_set_init; + goto err_set_expr_alloc; } set->exprs[i++] = expr; set->num_exprs++; } }
- udata = NULL; - if (udlen) { - udata = set->data + size; - nla_memcpy(udata, nla[NFTA_SET_USERDATA], udlen); - } - - INIT_LIST_HEAD(&set->bindings); - set->table = table; - write_pnet(&set->net, net); - set->ops = ops; - set->ktype = ktype; - set->klen = desc.klen; - set->dtype = dtype; - set->objtype = objtype; - set->dlen = desc.dlen; - set->flags = flags; - set->size = desc.size; - set->policy = policy; - set->udlen = udlen; - set->udata = udata; - set->timeout = timeout; - set->gc_int = gc_int; set->handle = nf_tables_alloc_handle(table);
- set->field_count = desc.field_count; - for (i = 0; i < desc.field_count; i++) - set->field_len[i] = desc.field_len[i]; - - err = ops->init(set, &desc, nla); - if (err < 0) - goto err_set_init; - err = nft_trans_set_add(&ctx, NFT_MSG_NEWSET, set); if (err < 0) - goto err_set_trans; + goto err_set_expr_alloc;
list_add_tail_rcu(&set->list, &table->sets); table->use++; return 0;
-err_set_trans: - ops->destroy(set); -err_set_init: +err_set_expr_alloc: for (i = 0; i < set->num_exprs; i++) nft_expr_destroy(&ctx, set->exprs[i]); -err_set_alloc_name: + + ops->destroy(set); +err_set_init: kfree(set->name); err_set_name: kvfree(set);