diff options
| author | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-08-09 11:01:27 +0200 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2019-08-09 14:41:13 +0200 |
| commit | 6a0a8d10a3661a036b55af695542a714c429ab7c (patch) | |
| tree | d0f8744b093a2e7723487f75caa8438fdae9a0b9 /net | |
| parent | 589b474a4b7ce409d6821ef17234a995841bd131 (diff) | |
netfilter: nf_tables: use-after-free in failing rule with bound set
If a rule that has already a bound anonymous set fails to be added, the
preparation phase releases the rule and the bound set. However, the
transaction object from the abort path still has a reference to the set
object that is stale, leading to a use-after-free when checking for the
set->bound field. Add a new field to the transaction that specifies if
the set is bound, so the abort path can skip releasing it since the rule
command owns it and it takes care of releasing it. After this update,
the set->bound field is removed.
[ 24.649883] Unable to handle kernel paging request at virtual address 0000000000040434
[ 24.657858] Mem abort info:
[ 24.660686] ESR = 0x96000004
[ 24.663769] Exception class = DABT (current EL), IL = 32 bits
[ 24.669725] SET = 0, FnV = 0
[ 24.672804] EA = 0, S1PTW = 0
[ 24.675975] Data abort info:
[ 24.678880] ISV = 0, ISS = 0x00000004
[ 24.682743] CM = 0, WnR = 0
[ 24.685723] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000428952000
[ 24.692207] [0000000000040434] pgd=0000000000000000
[ 24.697119] Internal error: Oops: 96000004 [#1] SMP
[...]
[ 24.889414] Call trace:
[ 24.891870] __nf_tables_abort+0x3f0/0x7a0
[ 24.895984] nf_tables_abort+0x20/0x40
[ 24.899750] nfnetlink_rcv_batch+0x17c/0x588
[ 24.904037] nfnetlink_rcv+0x13c/0x190
[ 24.907803] netlink_unicast+0x18c/0x208
[ 24.911742] netlink_sendmsg+0x1b0/0x350
[ 24.915682] sock_sendmsg+0x4c/0x68
[ 24.919185] ___sys_sendmsg+0x288/0x2c8
[ 24.923037] __sys_sendmsg+0x7c/0xd0
[ 24.926628] __arm64_sys_sendmsg+0x2c/0x38
[ 24.930744] el0_svc_common.constprop.0+0x94/0x158
[ 24.935556] el0_svc_handler+0x34/0x90
[ 24.939322] el0_svc+0x8/0xc
[ 24.942216] Code: 37280300 f9404023 91014262 aa1703e0 (f9401863)
[ 24.948336] ---[ end trace cebbb9dcbed3b56f ]---
Fixes: f6ac85858976 ("netfilter: nf_tables: unbind set in rule from commit path")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net')
| -rw-r--r-- | net/netfilter/nf_tables_api.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 605a7cfe7ca7..88abbddf8967 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -138,9 +138,14 @@ static void nft_set_trans_bind(const struct nft_ctx *ctx, struct nft_set *set) return; list_for_each_entry_reverse(trans, &net->nft.commit_list, list) { - if (trans->msg_type == NFT_MSG_NEWSET && - nft_trans_set(trans) == set) { - set->bound = true; + switch (trans->msg_type) { + case NFT_MSG_NEWSET: + if (nft_trans_set(trans) == set) + nft_trans_set_bound(trans) = true; + break; + case NFT_MSG_NEWSETELEM: + if (nft_trans_elem_set(trans) == set) + nft_trans_elem_set_bound(trans) = true; break; } } @@ -6906,7 +6911,7 @@ static int __nf_tables_abort(struct net *net) break; case NFT_MSG_NEWSET: trans->ctx.table->use--; - if (nft_trans_set(trans)->bound) { + if (nft_trans_set_bound(trans)) { nft_trans_destroy(trans); break; } @@ -6918,7 +6923,7 @@ static int __nf_tables_abort(struct net *net) nft_trans_destroy(trans); break; case NFT_MSG_NEWSETELEM: - if (nft_trans_elem_set(trans)->bound) { + if (nft_trans_elem_set_bound(trans)) { nft_trans_destroy(trans); break; } |