We currently have two levels of strict validation:
1) liberal (default)
- undefined (type >= max) & NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
- garbage at end of message accepted
2) strict (opt-in)
- NLA_UNSPEC attributes accepted
- attribute length >= expected accepted
Split out parsing strictness into four different options:
* TRAILING - check that there's no trailing data after parsing
attributes (in message or nested)
* MAXTYPE - reject attrs > max known type
* UNSPEC - reject attributes with NLA_UNSPEC policy entries
* STRICT_ATTRS - strictly validate attribute size
The default for future things should be *everything*.
The current *_strict() is a combination of TRAILING and MAXTYPE,
and is renamed to _deprecated_strict().
The current regular parsing has none of this, and is renamed to
*_parse_deprecated().
Additionally it allows us to selectively set one of the new flags
even on old policies. Notably, the UNSPEC flag could be useful in
this case, since it can be arranged (by filling in the policy) to
not be an incompatible userspace ABI change, but would then going
forward prevent forgetting attribute entries. Similar can apply
to the POLICY flag.
We end up with the following renames:
* nla_parse -> nla_parse_deprecated
* nla_parse_strict -> nla_parse_deprecated_strict
* nlmsg_parse -> nlmsg_parse_deprecated
* nlmsg_parse_strict -> nlmsg_parse_deprecated_strict
* nla_parse_nested -> nla_parse_nested_deprecated
* nla_validate_nested -> nla_validate_nested_deprecated
Using spatch, of course:
@@
expression TB, MAX, HEAD, LEN, POL, EXT;
@@
-nla_parse(TB, MAX, HEAD, LEN, POL, EXT)
+nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression NLH, HDRLEN, TB, MAX, POL, EXT;
@@
-nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
+nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT)
@@
expression TB, MAX, NLA, POL, EXT;
@@
-nla_parse_nested(TB, MAX, NLA, POL, EXT)
+nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT)
@@
expression START, MAX, POL, EXT;
@@
-nla_validate_nested(START, MAX, POL, EXT)
+nla_validate_nested_deprecated(START, MAX, POL, EXT)
@@
expression NLH, HDRLEN, MAX, POL, EXT;
@@
-nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT)
+nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT)
For this patch, don't actually add the strict, non-renamed versions
yet so that it breaks compile if I get it wrong.
Also, while at it, make nla_validate and nla_parse go down to a
common __nla_validate_parse() function to avoid code duplication.
Ultimately, this allows us to have very strict validation for every
new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the
next patch, while existing things will continue to work as is.
In effect then, this adds fully strict validation for any new command.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek <mkubecek@suse.cz> Acked-by: Jiri Pirko <jiri@mellanox.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
When running a syz script, a panic occurred:
[ 156.088228] BUG: KASAN: use-after-free in tipc_disc_timeout+0x9c9/0xb20 [tipc]
[ 156.094315] Call Trace:
[ 156.094844] <IRQ>
[ 156.095306] dump_stack+0x7c/0xc0
[ 156.097346] print_address_description+0x65/0x22e
[ 156.100445] kasan_report.cold.3+0x37/0x7a
[ 156.102402] tipc_disc_timeout+0x9c9/0xb20 [tipc]
[ 156.106517] call_timer_fn+0x19a/0x610
[ 156.112749] run_timer_softirq+0xb51/0x1090
It was caused by the netns freed without deleting the discoverer timer,
while later on the netns would be accessed in the timer handler.
The timer should have been deleted by tipc_net_stop() when cleaning up a
netns. However, tipc has been able to enable a bearer and start d->timer
without the local node_addr set since Commit 52dfae5c85a4 ("tipc: obtain
node identity from interface by default"), which caused the timer not to
be deleted in tipc_net_stop() then.
So fix it in tipc_net_stop() by changing to check local node_id instead
of local node_addr, as Jon suggested.
While at it, remove the calling of tipc_nametbl_withdraw() there, since
tipc_nametbl_stop() will take of the nametbl's freeing after.
Fixes: 52dfae5c85a4 ("tipc: obtain node identity from interface by default")
Reported-by: syzbot+a25307ad099309f1c2b9@syzkaller.appspotmail.com
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We get the following warning:
[ 47.926140] 32-bit node address hash set to 2010a0a
[ 47.927202]
[ 47.927433] ================================
[ 47.928050] WARNING: inconsistent lock state
[ 47.928661] 4.19.0+ #37 Tainted: G E
[ 47.929346] --------------------------------
[ 47.929954] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
[ 47.930116] swapper/3/0 [HC0[0]:SC1[3]:HE1:SE0] takes:
[ 47.930116] 00000000af8bc31e (&(&ht->lock)->rlock){+.?.}, at: rhashtable_walk_enter+0x36/0xb0
[ 47.930116] {SOFTIRQ-ON-W} state was registered at:
[ 47.930116] _raw_spin_lock+0x29/0x60
[ 47.930116] rht_deferred_worker+0x556/0x810
[ 47.930116] process_one_work+0x1f5/0x540
[ 47.930116] worker_thread+0x64/0x3e0
[ 47.930116] kthread+0x112/0x150
[ 47.930116] ret_from_fork+0x3a/0x50
[ 47.930116] irq event stamp: 14044
[ 47.930116] hardirqs last enabled at (14044): [<ffffffff9a07fbba>] __local_bh_enable_ip+0x7a/0xf0
[ 47.938117] hardirqs last disabled at (14043): [<ffffffff9a07fb81>] __local_bh_enable_ip+0x41/0xf0
[ 47.938117] softirqs last enabled at (14028): [<ffffffff9a0803ee>] irq_enter+0x5e/0x60
[ 47.938117] softirqs last disabled at (14029): [<ffffffff9a0804a5>] irq_exit+0xb5/0xc0
[ 47.938117]
[ 47.938117] other info that might help us debug this:
[ 47.938117] Possible unsafe locking scenario:
[ 47.938117]
[ 47.938117] CPU0
[ 47.938117] ----
[ 47.938117] lock(&(&ht->lock)->rlock);
[ 47.938117] <Interrupt>
[ 47.938117] lock(&(&ht->lock)->rlock);
[ 47.938117]
[ 47.938117] *** DEADLOCK ***
[ 47.938117]
[ 47.938117] 2 locks held by swapper/3/0:
[ 47.938117] #0: 0000000062c64f90 ((&d->timer)){+.-.}, at: call_timer_fn+0x5/0x280
[ 47.938117] #1: 00000000ee39619c (&(&d->lock)->rlock){+.-.}, at: tipc_disc_timeout+0xc8/0x540 [tipc]
[ 47.938117]
[ 47.938117] stack backtrace:
[ 47.938117] CPU: 3 PID: 0 Comm: swapper/3 Tainted: G E 4.19.0+ #37
[ 47.938117] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 47.938117] Call Trace:
[ 47.938117] <IRQ>
[ 47.938117] dump_stack+0x5e/0x8b
[ 47.938117] print_usage_bug+0x1ed/0x1ff
[ 47.938117] mark_lock+0x5b5/0x630
[ 47.938117] __lock_acquire+0x4c0/0x18f0
[ 47.938117] ? lock_acquire+0xa6/0x180
[ 47.938117] lock_acquire+0xa6/0x180
[ 47.938117] ? rhashtable_walk_enter+0x36/0xb0
[ 47.938117] _raw_spin_lock+0x29/0x60
[ 47.938117] ? rhashtable_walk_enter+0x36/0xb0
[ 47.938117] rhashtable_walk_enter+0x36/0xb0
[ 47.938117] tipc_sk_reinit+0xb0/0x410 [tipc]
[ 47.938117] ? mark_held_locks+0x6f/0x90
[ 47.938117] ? __local_bh_enable_ip+0x7a/0xf0
[ 47.938117] ? lockdep_hardirqs_on+0x20/0x1a0
[ 47.938117] tipc_net_finalize+0xbf/0x180 [tipc]
[ 47.938117] tipc_disc_timeout+0x509/0x540 [tipc]
[ 47.938117] ? call_timer_fn+0x5/0x280
[ 47.938117] ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc]
[ 47.938117] ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc]
[ 47.938117] call_timer_fn+0xa1/0x280
[ 47.938117] ? tipc_disc_msg_xmit.isra.19+0xa0/0xa0 [tipc]
[ 47.938117] run_timer_softirq+0x1f2/0x4d0
[ 47.938117] __do_softirq+0xfc/0x413
[ 47.938117] irq_exit+0xb5/0xc0
[ 47.938117] smp_apic_timer_interrupt+0xac/0x210
[ 47.938117] apic_timer_interrupt+0xf/0x20
[ 47.938117] </IRQ>
[ 47.938117] RIP: 0010:default_idle+0x1c/0x140
[ 47.938117] Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 41 54 55 53 65 8b 2d d8 2b 74 65 0f 1f 44 00 00 e8 c6 2c 8b ff fb f4 <65> 8b 2d c5 2b 74 65 0f 1f 44 00 00 5b 5d 41 5c c3 65 8b 05 b4 2b
[ 47.938117] RSP: 0018:ffffaf6ac0207ec8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
[ 47.938117] RAX: ffff8f5b3735e200 RBX: 0000000000000003 RCX: 0000000000000001
[ 47.938117] RDX: 0000000000000001 RSI: 0000000000000001 RDI: ffff8f5b3735e200
[ 47.938117] RBP: 0000000000000003 R08: 0000000000000001 R09: 0000000000000000
[ 47.938117] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
[ 47.938117] R13: 0000000000000000 R14: ffff8f5b3735e200 R15: ffff8f5b3735e200
[ 47.938117] ? default_idle+0x1a/0x140
[ 47.938117] do_idle+0x1bc/0x280
[ 47.938117] cpu_startup_entry+0x19/0x20
[ 47.938117] start_secondary+0x187/0x1c0
[ 47.938117] secondary_startup_64+0xa4/0xb0
The reason seems to be that tipc_net_finalize()->tipc_sk_reinit() is
calling the function rhashtable_walk_enter() within a timer interrupt.
We fix this by executing tipc_net_finalize() in work queue context.
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 9faa89d4ed9d ("tipc: make function tipc_net_finalize() thread
safe") tries to make it thread safe to set node address, so it uses
node_list_lock lock to serialize the whole process of setting node
address in tipc_net_finalize(). But it causes the following interrupt
unsafe locking scenario:
CPU0 CPU1
---- ----
rht_deferred_worker()
rhashtable_rehash_table()
lock(&(&ht->lock)->rlock)
tipc_nl_compat_doit()
tipc_net_finalize()
local_irq_disable();
lock(&(&tn->node_list_lock)->rlock);
tipc_sk_reinit()
rhashtable_walk_enter()
lock(&(&ht->lock)->rlock);
<Interrupt>
tipc_disc_rcv()
tipc_node_check_dest()
tipc_node_create()
lock(&(&tn->node_list_lock)->rlock);
*** DEADLOCK ***
When rhashtable_rehash_table() holds ht->lock on CPU0, it doesn't
disable BH. So if an interrupt happens after the lock, it can create
an inverse lock ordering between ht->lock and tn->node_list_lock. As
a consequence, deadlock might happen.
The reason causing the inverse lock ordering scenario above is because
the initial purpose of node_list_lock is not designed to do the
serialization of node address setting.
As cmpxchg() can guarantee CAS (compare-and-swap) process is atomic,
we use it to replace node_list_lock to ensure setting node address can
be atomically finished. It turns out the potential deadlock can be
avoided as well.
Fixes: 9faa89d4ed9d ("tipc: make function tipc_net_finalize() thread safe")
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Acked-by: Jon Maloy <maloy@donjonn.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The setting of the node address is not thread safe, meaning that
two discoverers may decide to set it simultanously, with a duplicate
entry in the name table as result. We fix that with this commit.
Fixes: 25b0b9c4e835 ("tipc: handle collisions of 32-bit node address hash values")
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
syzbot reported a crash in __tipc_nl_net_set() caused by NULL dereference.
We need to check that both TIPC_NLA_NET_NODEID and TIPC_NLA_NET_NODEID_W1
are present.
We also need to make sure userland provided u64 attributes.
Fixes: d50ccc2d3909 ("tipc: add 128-bit node identifier")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jon Maloy <jon.maloy@ericsson.com>
Cc: Ying Xue <ying.xue@windriver.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
With the new RB tree structure for service ranges it becomes possible to solve an old problem; - we can now allow overlapping service ranges in the table. When inserting a new service range to the tree, we use 'lower' as primary key, and when necessary 'upper' as secondary key. Since there may now be multiple service ranges matching an indicated 'lower' value, we must also add the 'upper' value to the functions used for removing publications, so that the correct, corresponding range item can be found. These changes guarantee that a well-formed publication/withdrawal item from a peer node never will be rejected, and make it possible to eliminate the problematic backlog functionality we currently have for handling such cases. Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
When a 32-bit node address is generated from a 128-bit identifier, there is a risk of collisions which must be discovered and handled. We do this as follows: - We don't apply the generated address immediately to the node, but do instead initiate a 1 sec trial period to allow other cluster members to discover and handle such collisions. - During the trial period the node periodically sends out a new type of message, DSC_TRIAL_MSG, using broadcast or emulated broadcast, to all the other nodes in the cluster. - When a node is receiving such a message, it must check that the presented 32-bit identifier either is unused, or was used by the very same peer in a previous session. In both cases it accepts the request by not responding to it. - If it finds that the same node has been up before using a different address, it responds with a DSC_TRIAL_FAIL_MSG containing that address. - If it finds that the address has already been taken by some other node, it generates a new, unused address and returns it to the requester. - During the trial period the requesting node must always be prepared to accept a failure message, i.e., a message where a peer suggests a different (or equal) address to the one tried. In those cases it must apply the suggested value as trial address and restart the trial period. This algorithm ensures that in the vast majority of cases a node will have the same address before and after a reboot. If a legacy user configures the address explicitly, there will be no trial period and messages, so this protocol addition is completely backwards compatible. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>
We add a 128-bit node identity, as an alternative to the currently used 32-bit node address. For the sake of compatibility and to minimize message header changes we retain the existing 32-bit address field. When not set explicitly by the user, this field will be filled with a hash value generated from the much longer node identity, and be used as a shorthand value for the latter. We permit either the address or the identity to be set by configuration, but not both, so when the address value is set by a legacy user the corresponding 128-bit node identity is generated based on the that value. Acked-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Jon Maloy <jon.maloy@ericsson.com> Signed-off-by: David S. Miller <davem@davemloft.net>