linux-stable.git/net/netfilter, branch v5.7.7

netfilter: ipset: fix unaligned atomic access

2020-06-30T19:36:10+00:00

[ Upstream commit 715028460082d07a7ec6fcd87b14b46784346a72 ]

When using ip_set with counters and comment, traffic causes the kernel
to panic on 32-bit ARM:

Alignment trap: not handling instruction e1b82f9f at []
Unhandled fault: alignment exception (0x221) at 0xea08133c
PC is at ip_set_match_extensions+0xe0/0x224 [ip_set]

The problem occurs when we try to update the 64-bit counters - the
faulting address above is not 64-bit aligned.  The problem occurs
due to the way elements are allocated, for example:

	set->dsize = ip_set_elem_len(set, tb, 0, 0);
	map = ip_set_alloc(sizeof(*map) + elements * set->dsize);

If the element has a requirement for a member to be 64-bit aligned,
and set->dsize is not a multiple of 8, but is a multiple of four,
then every odd numbered elements will be misaligned - and hitting
an atomic64_add() on that element will cause the kernel to panic.

ip_set_elem_len() must return a size that is rounded to the maximum
alignment of any extension field stored in the element.  This change
ensures that is the case.

Fixes: 95ad1f4a9358 ("netfilter: ipset: Fix extension alignment")
Signed-off-by: Russell King 
Acked-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nft_set_pipapo: Disable preemption before getting per-CPU pointer

2020-06-24T15:49:25+00:00

commit c3829285b2e6a0d5461078d7f6cbb2c2b4bf8c4e upstream.

The lkp kernel test robot reports, with CONFIG_DEBUG_PREEMPT enabled:

  [  165.316525] BUG: using smp_processor_id() in preemptible [00000000] code: nft/6247
  [  165.319547] caller is nft_pipapo_insert+0x464/0x610 [nf_tables]
  [  165.321846] CPU: 1 PID: 6247 Comm: nft Not tainted 5.6.0-rc5-01595-ge32a4dc6512ce3 #1
  [  165.332128] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
  [  165.334892] Call Trace:
  [  165.336435]  dump_stack+0x8f/0xcb
  [  165.338128]  debug_smp_processor_id+0xb2/0xc0
  [  165.340117]  nft_pipapo_insert+0x464/0x610 [nf_tables]
  [  165.342290]  ? nft_trans_alloc_gfp+0x1c/0x60 [nf_tables]
  [  165.344420]  ? rcu_read_lock_sched_held+0x52/0x80
  [  165.346460]  ? nft_trans_alloc_gfp+0x1c/0x60 [nf_tables]
  [  165.348543]  ? __mmu_interval_notifier_insert+0xa0/0xf0
  [  165.350629]  nft_add_set_elem+0x5ff/0xa90 [nf_tables]
  [  165.352699]  ? __lock_acquire+0x241/0x1400
  [  165.354573]  ? __lock_acquire+0x241/0x1400
  [  165.356399]  ? reacquire_held_locks+0x12f/0x200
  [  165.358384]  ? nf_tables_valid_genid+0x1f/0x40 [nf_tables]
  [  165.360502]  ? nla_strcmp+0x10/0x50
  [  165.362199]  ? nft_table_lookup+0x4f/0xa0 [nf_tables]
  [  165.364217]  ? nla_strcmp+0x10/0x50
  [  165.365891]  ? nf_tables_newsetelem+0xd5/0x150 [nf_tables]
  [  165.367997]  nf_tables_newsetelem+0xd5/0x150 [nf_tables]
  [  165.370083]  nfnetlink_rcv_batch+0x4fd/0x790 [nfnetlink]
  [  165.372205]  ? __lock_acquire+0x241/0x1400
  [  165.374058]  ? __nla_validate_parse+0x57/0x8a0
  [  165.375989]  ? cap_inode_getsecurity+0x230/0x230
  [  165.377954]  ? security_capable+0x38/0x50
  [  165.379795]  nfnetlink_rcv+0x11d/0x140 [nfnetlink]
  [  165.381779]  netlink_unicast+0x1b2/0x280
  [  165.383612]  netlink_sendmsg+0x351/0x470
  [  165.385439]  sock_sendmsg+0x5b/0x60
  [  165.387133]  ____sys_sendmsg+0x200/0x280
  [  165.388871]  ? copy_msghdr_from_user+0xd9/0x160
  [  165.390805]  ___sys_sendmsg+0x88/0xd0
  [  165.392524]  ? __might_fault+0x3e/0x90
  [  165.394273]  ? sock_getsockopt+0x3d5/0xbb0
  [  165.396021]  ? __handle_mm_fault+0x545/0x6a0
  [  165.397822]  ? find_held_lock+0x2d/0x90
  [  165.399593]  ? __sys_sendmsg+0x5e/0xa0
  [  165.401338]  __sys_sendmsg+0x5e/0xa0
  [  165.402979]  do_syscall_64+0x60/0x280
  [  165.404680]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [  165.406621] RIP: 0033:0x7ff1fa46e783
  [  165.408299] Code: c7 c0 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 64 8b 04 25 18 00 00 00 85 c0 75 14 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 55 c3 0f 1f 40 00 48 83 ec 28 89 54 24 1c 48
  [  165.414163] RSP: 002b:00007ffedf59ea78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
  [  165.416804] RAX: ffffffffffffffda RBX: 00007ffedf59fc60 RCX: 00007ff1fa46e783
  [  165.419419] RDX: 0000000000000000 RSI: 00007ffedf59fb10 RDI: 0000000000000005
  [  165.421886] RBP: 00007ffedf59fc10 R08: 00007ffedf59ea54 R09: 0000000000000001
  [  165.424445] R10: 00007ff1fa630c6c R11: 0000000000000246 R12: 0000000000020000
  [  165.426954] R13: 0000000000000280 R14: 0000000000000005 R15: 00007ffedf59ea90

Disable preemption before accessing the lookup scratch area in
nft_pipapo_insert().

Reported-by: kernel test robot 
Analysed-by: Florian Westphal 
Cc:  # 5.6.x
Fixes: 3c4287f62044 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Stefano Brivio 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nft_set_rbtree: Don't account for expired elements on insertion

2020-06-24T15:49:25+00:00

commit 33d077996a87175b155fe88030e8fec7ca76327e upstream.

While checking the validity of insertion in __nft_rbtree_insert(),
we currently ignore conflicting elements and intervals only if they
are not active within the next generation.

However, if we consider expired elements and intervals as
potentially conflicting and overlapping, we'll return error for
entries that should be added instead. This is particularly visible
with garbage collection intervals that are comparable with the
element timeout itself, as reported by Mike Dillinger.

Other than the simple issue of denying insertion of valid entries,
this might also result in insertion of a single element (opening or
closing) out of a given interval. With single entries (that are
inserted as intervals of size 1), this leads in turn to the creation
of new intervals. For example:

  # nft add element t s { 192.0.2.1 }
  # nft list ruleset
  [...]
     elements = { 192.0.2.1-255.255.255.255 }

Always ignore expired elements active in the next generation, while
checking for conflicts.

It might be more convenient to introduce a new macro that covers
both inactive and expired items, as this type of check also appears
quite frequently in other set back-ends. This is however beyond the
scope of this fix and can be deferred to a separate patch.

Other than the overlap detection cases introduced by commit
7c84d41416d8 ("netfilter: nft_set_rbtree: Detect partial overlaps
on insertion"), we also have to cover the original conflict check
dealing with conflicts between two intervals of size 1, which was
introduced before support for timeout was introduced. This won't
return an error to the user as -EEXIST is masked by nft if
NLM_F_EXCL is not given, but would result in a silent failure
adding the entry.

Reported-by: Mike Dillinger 
Cc:  # 5.6.x
Fixes: 8d8540c4f5e0 ("netfilter: nft_set_rbtree: add timeout support")
Fixes: 7c84d41416d8 ("netfilter: nft_set_rbtree: Detect partial overlaps on insertion")
Signed-off-by: Stefano Brivio 
Acked-by: Phil Sutter 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nft_nat: return EOPNOTSUPP if type or flags are not supported

2020-06-22T07:32:33+00:00

[ Upstream commit 0d7c83463fdf7841350f37960a7abadd3e650b41 ]

Instead of EINVAL which should be used for malformed netlink messages.

Fixes: eb31628e37a0 ("netfilter: nf_tables: Add support for IPv6 NAT")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_conntrack_pptp: fix compilation warning with W=1 build

2020-05-27T11:39:08+00:00

>> include/linux/netfilter/nf_conntrack_pptp.h:13:20: warning: 'const' type qualifier on return type has no effect [-Wignored-qualifiers]
extern const char *const pptp_msg_name(u_int16_t msg);
^~~~~~

Reported-by: kbuild test robot 
Fixes: 4c559f15efcc ("netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code")
Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: comparison of unsigned in cthelper confirmation

2020-05-27T11:39:06+00:00

net/netfilter/nf_conntrack_core.c: In function nf_confirm_cthelper:
net/netfilter/nf_conntrack_core.c:2117:15: warning: comparison of unsigned expression in < 0 is always false [-Wtype-limits]
 2117 |   if (protoff < 0 || (frag_off & htons(~0x7)) != 0)
      |               ^

ipv6_skip_exthdr() returns a signed integer.

Reported-by: Colin Ian King 
Fixes: 703acd70f249 ("netfilter: nfnetlink_cthelper: unbreak userspace helper support")
Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: Pass value of ctinfo to __nf_conntrack_update

2020-05-27T11:38:58+00:00

Clang warns:

net/netfilter/nf_conntrack_core.c:2068:21: warning: variable 'ctinfo' is
uninitialized when used here [-Wuninitialized]
        nf_ct_set(skb, ct, ctinfo);
                           ^~~~~~
net/netfilter/nf_conntrack_core.c:2024:2: note: variable 'ctinfo' is
declared here
        enum ip_conntrack_info ctinfo;
        ^
1 warning generated.

nf_conntrack_update was split up into nf_conntrack_update and
__nf_conntrack_update, where the assignment of ctinfo is in
nf_conntrack_update but it is used in __nf_conntrack_update.

Pass the value of ctinfo from nf_conntrack_update to
__nf_conntrack_update so that uninitialized memory is not used
and everything works properly.

Fixes: ee04805ff54a ("netfilter: conntrack: make conntrack userspace helpers work again")
Link: https://github.com/ClangBuiltLinux/linux/issues/1039
Signed-off-by: Nathan Chancellor 
Signed-off-by: Pablo Neira Ayuso

netfilter: nfnetlink_cthelper: unbreak userspace helper support

2020-05-25T18:39:14+00:00

Restore helper data size initialization and fix memcopy of the helper
data size.

Fixes: 157ffffeb5dc ("netfilter: nfnetlink_cthelper: reject too large userspace allocation requests")
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: make conntrack userspace helpers work again

2020-05-25T18:39:14+00:00

Florian Westphal says:

"Problem is that after the helper hook was merged back into the confirm
one, the queueing itself occurs from the confirm hook, i.e. we queue
from the last netfilter callback in the hook-list.

Therefore, on return, the packet bypasses the confirm action and the
connection is never committed to the main conntrack table.

To fix this there are several ways:
1. revert the 'Fixes' commit and have a extra helper hook again.
   Works, but has the drawback of adding another indirect call for
   everyone.

2. Special case this: split the hooks only when userspace helper
   gets added, so queueing occurs at a lower priority again,
   and normal enqueue reinject would eventually call the last hook.

3. Extend the existing nf_queue ct update hook to allow a forced
   confirmation (plus run the seqadj code).

This goes for 3)."

Fixes: 827318feb69cb ("netfilter: conntrack: remove helper hook again")
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_conntrack_pptp: prevent buffer overflows in debug code

2020-05-25T18:39:14+00:00

Dan Carpenter says: "Smatch complains that the value for "cmd" comes
from the network and can't be trusted."

Add pptp_msg_name() helper function that checks for the array boundary.

Fixes: f09943fefe6b ("[NETFILTER]: nf_conntrack/nf_nat: add PPTP helper port")
Reported-by: Dan Carpenter 
Signed-off-by: Pablo Neira Ayuso