4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexey Kodanev alexey.kodanev@oracle.com
[ Upstream commit 9c7f96fd77b0dbe1fe7ed1f9c462c45dc48a1076 ]
The patch moves the "trans->msg_type == NFT_MSG_NEWSET" check before using nft_trans_set(trans). Otherwise we can get out of bounds read.
For example, KASAN reported the one when running 0001_cache_handling_0 nft test. In this case "trans->msg_type" was NFT_MSG_NEWTABLE:
[75517.177808] BUG: KASAN: slab-out-of-bounds in nft_set_lookup_global+0x22f/0x270 [nf_tables] [75517.279094] Read of size 8 at addr ffff881bdb643fc8 by task nft/7356 ... [75517.375605] CPU: 26 PID: 7356 Comm: nft Tainted: G E 4.17.0-rc7.1.x86_64 #1 [75517.489587] Hardware name: Oracle Corporation SUN SERVER X4-2 [75517.618129] Call Trace: [75517.648821] dump_stack+0xd1/0x13b [75517.691040] ? show_regs_print_info+0x5/0x5 [75517.742519] ? kmsg_dump_rewind_nolock+0xf5/0xf5 [75517.799300] ? lock_acquire+0x143/0x310 [75517.846738] print_address_description+0x85/0x3a0 [75517.904547] kasan_report+0x18d/0x4b0 [75517.949892] ? nft_set_lookup_global+0x22f/0x270 [nf_tables] [75518.019153] ? nft_set_lookup_global+0x22f/0x270 [nf_tables] [75518.088420] ? nft_set_lookup_global+0x22f/0x270 [nf_tables] [75518.157689] nft_set_lookup_global+0x22f/0x270 [nf_tables] [75518.224869] nf_tables_newsetelem+0x1a5/0x5d0 [nf_tables] [75518.291024] ? nft_add_set_elem+0x2280/0x2280 [nf_tables] [75518.357154] ? nla_parse+0x1a5/0x300 [75518.401455] ? kasan_kmalloc+0xa6/0xd0 [75518.447842] nfnetlink_rcv+0xc43/0x1bdf [nfnetlink] [75518.507743] ? nfnetlink_rcv+0x7a5/0x1bdf [nfnetlink] [75518.569745] ? nfnl_err_reset+0x3c0/0x3c0 [nfnetlink] [75518.631711] ? lock_acquire+0x143/0x310 [75518.679133] ? netlink_deliver_tap+0x9b/0x1070 [75518.733840] ? kasan_unpoison_shadow+0x31/0x40 [75518.788542] netlink_unicast+0x45d/0x680 [75518.837111] ? __isolate_free_page+0x890/0x890 [75518.891913] ? netlink_attachskb+0x6b0/0x6b0 [75518.944542] netlink_sendmsg+0x6fa/0xd30 [75518.993107] ? netlink_unicast+0x680/0x680 [75519.043758] ? netlink_unicast+0x680/0x680 [75519.094402] sock_sendmsg+0xd9/0x160 [75519.138810] ___sys_sendmsg+0x64d/0x980 [75519.186234] ? copy_msghdr_from_user+0x350/0x350 [75519.243118] ? lock_downgrade+0x650/0x650 [75519.292738] ? do_raw_spin_unlock+0x5d/0x250 [75519.345456] ? _raw_spin_unlock+0x24/0x30 [75519.395065] ? __handle_mm_fault+0xbde/0x3410 [75519.448830] ? sock_setsockopt+0x3d2/0x1940 [75519.500516] ? __lock_acquire.isra.25+0xdc/0x19d0 [75519.558448] ? lock_downgrade+0x650/0x650 [75519.608057] ? __audit_syscall_entry+0x317/0x720 [75519.664960] ? __fget_light+0x58/0x250 [75519.711325] ? __sys_sendmsg+0xde/0x170 [75519.758850] __sys_sendmsg+0xde/0x170 [75519.804193] ? __ia32_sys_shutdown+0x90/0x90 [75519.856725] ? syscall_trace_enter+0x897/0x10e0 [75519.912354] ? trace_event_raw_event_sys_enter+0x920/0x920 [75519.979432] ? __audit_syscall_entry+0x720/0x720 [75520.036118] do_syscall_64+0xa3/0x3d0 [75520.081248] ? prepare_exit_to_usermode+0x47/0x1d0 [75520.139904] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [75520.201680] RIP: 0033:0x7fc153320ba0 [75520.245772] RSP: 002b:00007ffe294c3638 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [75520.337708] RAX: ffffffffffffffda RBX: 00007ffe294c4820 RCX: 00007fc153320ba0 [75520.424547] RDX: 0000000000000000 RSI: 00007ffe294c46b0 RDI: 0000000000000003 [75520.511386] RBP: 00007ffe294c47b0 R08: 0000000000000004 R09: 0000000002114090 [75520.598225] R10: 00007ffe294c30a0 R11: 0000000000000246 R12: 00007ffe294c3660 [75520.684961] R13: 0000000000000001 R14: 00007ffe294c3650 R15: 0000000000000001
[75520.790946] Allocated by task 7356: [75520.833994] kasan_kmalloc+0xa6/0xd0 [75520.878088] __kmalloc+0x189/0x450 [75520.920107] nft_trans_alloc_gfp+0x20/0x190 [nf_tables] [75520.983961] nf_tables_newtable+0xcd0/0x1bd0 [nf_tables] [75521.048857] nfnetlink_rcv+0xc43/0x1bdf [nfnetlink] [75521.108655] netlink_unicast+0x45d/0x680 [75521.157013] netlink_sendmsg+0x6fa/0xd30 [75521.205271] sock_sendmsg+0xd9/0x160 [75521.249365] ___sys_sendmsg+0x64d/0x980 [75521.296686] __sys_sendmsg+0xde/0x170 [75521.341822] do_syscall_64+0xa3/0x3d0 [75521.386957] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[75521.467867] Freed by task 23454: [75521.507804] __kasan_slab_free+0x132/0x180 [75521.558137] kfree+0x14d/0x4d0 [75521.596005] free_rt_sched_group+0x153/0x280 [75521.648410] sched_autogroup_create_attach+0x19a/0x520 [75521.711330] ksys_setsid+0x2ba/0x400 [75521.755529] __ia32_sys_setsid+0xa/0x10 [75521.802850] do_syscall_64+0xa3/0x3d0 [75521.848090] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[75521.929000] The buggy address belongs to the object at ffff881bdb643f80 which belongs to the cache kmalloc-96 of size 96 [75522.079797] The buggy address is located 72 bytes inside of 96-byte region [ffff881bdb643f80, ffff881bdb643fe0) [75522.221234] The buggy address belongs to the page: [75522.280100] page:ffffea006f6d90c0 count:1 mapcount:0 mapping:0000000000000000 index:0x0 [75522.377443] flags: 0x2fffff80000100(slab) [75522.426956] raw: 002fffff80000100 0000000000000000 0000000000000000 0000000180200020 [75522.521275] raw: ffffea006e6fafc0 0000000c0000000c ffff881bf180f400 0000000000000000 [75522.615601] page dumped because: kasan: bad access detected
Fixes: 37a9cc525525 ("netfilter: nf_tables: add generation mask to sets") Signed-off-by: Alexey Kodanev alexey.kodanev@oracle.com Acked-by: Florian Westphal fw@strlen.de Signed-off-by: Pablo Neira Ayuso pablo@netfilter.org Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netfilter/nf_tables_api.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-)
--- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -2710,12 +2710,13 @@ static struct nft_set *nf_tables_set_loo u32 id = ntohl(nla_get_be32(nla));
list_for_each_entry(trans, &net->nft.commit_list, list) { - struct nft_set *set = nft_trans_set(trans); + if (trans->msg_type == NFT_MSG_NEWSET) { + struct nft_set *set = nft_trans_set(trans);
- if (trans->msg_type == NFT_MSG_NEWSET && - id == nft_trans_set_id(trans) && - nft_active_genmask(set, genmask)) - return set; + if (id == nft_trans_set_id(trans) && + nft_active_genmask(set, genmask)) + return set; + } } return ERR_PTR(-ENOENT); }