fib6_metric_set() may be called concurrently from softirq context without
holding the FIB table lock. A typical path is:
ndisc_router_discovery()
spin_unlock_bh(&table->tb6_lock) <- lock released
fib6_metric_set(rt, RTAX_HOPLIMIT, ...) <- lockless call
When two CPUs process Router Advertisement packets for the same router
simultaneously, they can both arrive at fib6_metric_set() with the same
fib6_info pointer whose fib6_metrics still points to dst_default_metrics.
if (f6i->fib6_metrics == &dst_default_metrics) { /* both CPUs: true */
struct dst_metrics *p = kzalloc_obj(*p, GFP_ATOMIC);
refcount_set(&p->refcnt, 1);
f6i->fib6_metrics = p; /* CPU1 overwrites CPU0's p -> p0 leaked */
}
The dst_metrics allocated by the losing CPU has refcnt=1 but no pointer
to it anywhere in memory, producing a kmemleak report:
unreferenced object 0xff1100025aca1400 (size 96):
comm "softirq", pid 0, jiffies 4299271239
backtrace:
kmalloc_trace+0x28a/0x380
fib6_metric_set+0xcd/0x180
ndisc_router_discovery+0x12dc/0x24b0
icmpv6_rcv+0xc16/0x1360
Fix this by:
- Set val for p->metrics before published via cmpxchg() so the metrics
value is ready before the pointer becomes visible to other CPUs.
- Replace the plain pointer store with cmpxchg() and free the allocation
safely when competition failed.
- Add READ_ONCE()/WRITE_ONCE() for metrics[] setting in the non-default
metrics path to prevent compiler-based data races.
Fixes: d4ead6b34b ("net/ipv6: move metrics from dst to rt6_info")
Reported-by: Fei Liu <feliu@redhat.com>
Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20260331-b4-fib6_metric_set-kmemleak-v3-1-88d27f4d8825@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The cited commit mechanically put fib6_remove_gc_list()
just after every fib6_clean_expires() call.
When a temporary route is promoted to a permanent route,
there may already be exception routes tied to it.
If fib6_remove_gc_list() removes the route from tb6_gc_hlist,
such exception routes will no longer be aged.
Let's replace fib6_remove_gc_list() with a new helper
fib6_may_remove_gc_list() and use fib6_age_exceptions() there.
Note that net->ipv6 is only compiled when CONFIG_IPV6 is
enabled, so fib6_{add,remove,may_remove}_gc_list() are guarded.
Fixes: 5eb902b8e7 ("net/ipv6: Remove expired routes with a separated list of routes.")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260320072317.2561779-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Commit 5eb902b8e7 ("net/ipv6: Remove expired routes with a
separated list of routes.") introduced a per-table GC list and
changed GC to iterate over that list instead of traversing
the entire route table.
However, it forgot to add permanent routes to tb6_gc_hlist
when exception routes are added.
Commit cfe82469a0 ("ipv6: add exception routes to GC list
in rt6_insert_exception") fixed that issue but introduced
another one.
Even after all exception routes expire, the permanent routes
remain in tb6_gc_hlist, potentially negating the performance
benefits intended by the initial change.
Let's count gc_args->more before and after rt6_age_exceptions()
and remove the permanent route when the delta is 0.
Note that the next patch will reuse fib6_age_exceptions().
Fixes: cfe82469a0 ("ipv6: add exception routes to GC list in rt6_insert_exception")
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20260320072317.2561779-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This converts some of the visually simpler cases that have been split
over multiple lines. I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.
Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script. I probably had made it a bit _too_ trivial.
So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.
The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
syzbot reported a kernel BUG in fib6_add_rt2node() when adding an IPv6
route. [0]
Commit f72514b3c5 ("ipv6: clear RA flags when adding a static
route") introduced logic to clear RTF_ADDRCONF from existing routes
when a static route with the same nexthop is added. However, this
causes a problem when the existing route has a gateway.
When RTF_ADDRCONF is cleared from a route that has a gateway, that
route becomes eligible for ECMP, i.e. rt6_qualify_for_ecmp() returns
true. The issue is that this route was never added to the
fib6_siblings list.
This leads to a mismatch between the following counts:
- The sibling count computed by iterating fib6_next chain, which
includes the newly ECMP-eligible route
- The actual siblings in fib6_siblings list, which does not include
that route
When a subsequent ECMP route is added, fib6_add_rt2node() hits
BUG_ON(sibling->fib6_nsiblings != rt->fib6_nsiblings) because the
counts don't match.
Fix this by only clearing RTF_ADDRCONF when the existing route does
not have a gateway. Routes without a gateway cannot qualify for ECMP
anyway (rt6_qualify_for_ecmp() requires fib_nh_gw_family), so clearing
RTF_ADDRCONF on them is safe and matches the original intent of the
commit.
[0]:
kernel BUG at net/ipv6/ip6_fib.c:1217!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 0 UID: 0 PID: 6010 Comm: syz.0.17 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:fib6_add_rt2node+0x3433/0x3470 net/ipv6/ip6_fib.c:1217
[...]
Call Trace:
<TASK>
fib6_add+0x8da/0x18a0 net/ipv6/ip6_fib.c:1532
__ip6_ins_rt net/ipv6/route.c:1351 [inline]
ip6_route_add+0xde/0x1b0 net/ipv6/route.c:3946
ipv6_route_ioctl+0x35c/0x480 net/ipv6/route.c:4571
inet6_ioctl+0x219/0x280 net/ipv6/af_inet6.c:577
sock_do_ioctl+0xdc/0x300 net/socket.c:1245
sock_ioctl+0x576/0x790 net/socket.c:1366
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Fixes: f72514b3c5 ("ipv6: clear RA flags when adding a static route")
Reported-by: syzbot+cb809def1baaac68ab92@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=cb809def1baaac68ab92
Tested-by: syzbot+cb809def1baaac68ab92@syzkaller.appspotmail.com
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260204095837.1285552-1-syoshida@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add READ_ONCE() on lockless reads of net->ipv6.sysctl.ip6_rt_gc_interval
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20260115094141.3124990-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When an IPv6 Router Advertisement (RA) is received for a prefix, the
kernel creates the corresponding on-link route with flags RTF_ADDRCONF
and RTF_PREFIX_RT configured and RTF_EXPIRES if lifetime is set.
If later a user configures a static IPv6 address on the same prefix the
kernel clears the RTF_EXPIRES flag but it doesn't clear the RTF_ADDRCONF
and RTF_PREFIX_RT. When the next RA for that prefix is received, the
kernel sees the route as RA-learned and wrongly configures back the
lifetime. This is problematic because if the route expires, the static
address won't have the corresponding on-link route.
This fix clears the RTF_ADDRCONF and RTF_PREFIX_RT flags preventing that
the lifetime is configured when the next RA arrives. If the static
address is deleted, the route becomes RA-learned again.
Fixes: 14ef37b6d0 ("ipv6: fix route lookup in addrconf_prefix_rcv()")
Reported-by: Garri Djavadyan <g.djavadyan@gmail.com>
Closes: https://lore.kernel.org/netdev/ba807d39aca5b4dcf395cc11dca61a130a52cfd3.camel@gmail.com/
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20251115095939.6967-1-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Merge in late fixes to prepare for the 6.17 net-next PR.
Conflicts:
net/core/neighbour.c
1bbb76a899 ("neighbour: Fix null-ptr-deref in neigh_flush_dev().")
13a936bb99 ("neighbour: Protect tbl->phash_buckets[] with a dedicated mutex.")
03dc03fa04 ("neighbor: Add NTF_EXT_VALIDATED flag for externally validated entries")
Adjacent changes:
drivers/net/usb/usbnet.c
0d9cfc9b8c ("net: usbnet: Avoid potential RCU stall on LINK_CHANGE event")
2c04d279e8 ("net: usb: Convert tasklet API to new bottom half workqueue mechanism")
net/ipv6/route.c
31d7d67ba1 ("ipv6: annotate data-races around rt->fib6_nsiblings")
1caf272972 ("ipv6: adopt dst_dev() helper")
3b3ccf9ed0 ("net: Remove unnecessary NULL check for lwtunnel_fill_encap()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
rt->fib6_nsiblings can be read locklessly, add corresponding
READ_ONCE() and WRITE_ONCE() annotations.
Fixes: 66f5d6ce53 ("ipv6: replace rwlock with rcu and spinlock in fib6_table")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250725140725.3626540-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
While testing prior patch, I was able to trigger
an infinite loop in rt6_nlmsg_size() in the following place:
list_for_each_entry_rcu(sibling, &f6i->fib6_siblings,
fib6_siblings) {
rt6_nh_nlmsg_size(sibling->fib6_nh, &nexthop_len);
}
This is because fib6_del_route() and fib6_add_rt2node()
uses list_del_rcu(), which can confuse rcu readers,
because they might no longer see the head of the list.
Restart the loop if f6i->fib6_nsiblings is zero.
Fixes: d9ccb18f83 ("ipv6: Fix soft lockups in fib6_select_path under high next hop churn")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250725140725.3626540-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since commit 0e23387491 ("ipv6: fix races in ip6_dst_destroy()"),
'table' is unused in __fib6_drop_pcpu_from(), no need pass it from
fib6_drop_pcpu_from().
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250701041235.1333687-1-yuehaibing@huawei.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Move this API to the canonical timer_*() namespace.
[ tglx: Redone against pre rc1 ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
Commit 169fd62799 ("ipv6: Get rid of RTNL for SIOCADDRT and
RTM_NEWROUTE.") added rcu_read_lock() covering
ip6_route_info_create_nh() and __ip6_ins_rt() to guarantee that
nexthop and netdev will not go away.
However, as reported by syzkaller [0], ip_tun_build_state() calls
dst_cache_init() with GFP_KERNEL during the RCU critical section.
ip6_route_info_create_nh() fetches nexthop or netdev depending on
whether RTA_NH_ID is set, and struct fib6_info holds a refcount
of either of them by nexthop_get() or netdev_get_by_index().
netdev_get_by_index() looks up a dev and calls dev_hold() under RCU.
So, we need RCU only around nexthop_find_by_id() and nexthop_get()
( and a few more nexthop code).
Let's add rcu_read_lock() there and remove rcu_read_lock() in
ip6_route_add() and ip6_route_multipath_add().
Now these functions called from fib6_add() need RCU:
- inet6_rt_notify()
- fib6_drop_pcpu_from() (via fib6_purge_rt())
- rt6_flush_exceptions() (via fib6_purge_rt())
- ip6_ignore_linkdown() (via rt6_multipath_rebalance())
All callers of inet6_rt_notify() need RCU, so rcu_read_lock() is
added there.
[0]:
[ BUG: Invalid wait context ]
6.15.0-rc4-syzkaller-00746-g836b313a14a3 #0 Tainted: G W
----------------------------
syz-executor234/5832 is trying to lock:
ffffffff8e021688 (pcpu_alloc_mutex){+.+.}-{4:4}, at:
pcpu_alloc_noprof+0x284/0x16b0 mm/percpu.c:1782
other info that might help us debug this:
context-{5:5}
1 lock held by syz-executor234/5832:
0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire
include/linux/rcupdate.h:331 [inline]
0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at: rcu_read_lock
include/linux/rcupdate.h:841 [inline]
0: ffffffff8df3b860 (rcu_read_lock){....}-{1:3}, at:
ip6_route_add+0x4d/0x2f0 net/ipv6/route.c:3913
stack backtrace:
CPU: 0 UID: 0 PID: 5832 Comm: syz-executor234 Tainted: G W
6.15.0-rc4-syzkaller-00746-g836b313a14a3 #0 PREEMPT(full)
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 04/29/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_lock_invalid_wait_context kernel/locking/lockdep.c:4831 [inline]
check_wait_context kernel/locking/lockdep.c:4903 [inline]
__lock_acquire+0xbcf/0xd20 kernel/locking/lockdep.c:5185
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5866
__mutex_lock_common kernel/locking/mutex.c:601 [inline]
__mutex_lock+0x182/0xe80 kernel/locking/mutex.c:746
pcpu_alloc_noprof+0x284/0x16b0 mm/percpu.c:1782
dst_cache_init+0x37/0xc0 net/core/dst_cache.c:145
ip_tun_build_state+0x193/0x6b0 net/ipv4/ip_tunnel_core.c:687
lwtunnel_build_state+0x381/0x4c0 net/core/lwtunnel.c:137
fib_nh_common_init+0x129/0x460 net/ipv4/fib_semantics.c:635
fib6_nh_init+0x15e4/0x2030 net/ipv6/route.c:3669
ip6_route_info_create_nh+0x139/0x870 net/ipv6/route.c:3866
ip6_route_add+0xf6/0x2f0 net/ipv6/route.c:3915
inet6_rtm_newroute+0x284/0x1c50 net/ipv6/route.c:5732
rtnetlink_rcv_msg+0x7cc/0xb70 net/core/rtnetlink.c:6955
netlink_rcv_skb+0x219/0x490 net/netlink/af_netlink.c:2534
netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:727
____sys_sendmsg+0x505/0x830 net/socket.c:2566
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620
__sys_sendmsg net/socket.c:2652 [inline]
__do_sys_sendmsg net/socket.c:2657 [inline]
__se_sys_sendmsg net/socket.c:2655 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
Fixes: 169fd62799 ("ipv6: Get rid of RTNL for SIOCADDRT and RTM_NEWROUTE.")
Reported-by: syzbot+bcc12d6799364500fbec@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=bcc12d6799364500fbec
Reported-by: Eric Dumazet <edumazet@google.com>
Closes: https://lore.kernel.org/netdev/CANn89i+r1cGacVC_6n3-A-WSkAa_Nr+pmxJ7Gt+oP-P9by2aGw@mail.gmail.com/
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250516022759.44392-4-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Once allocated, the IPv6 routing table is not freed until
netns is dismantled.
fib6_get_table() uses rcu_read_lock() while iterating
net->ipv6.fib_table_hash[], but it's not needed and
rather confusing.
Because some callers have this pattern,
table = fib6_get_table();
rcu_read_lock();
/* ... use table here ... */
rcu_read_unlock();
[ See: addrconf_get_prefix_route(), ip6_route_del(),
rt6_get_route_info(), rt6_get_dflt_router() ]
and this looks illegal but is actually safe.
Let's remove rcu_read_lock() in fib6_get_table() and pass true
to the last argument of hlist_for_each_entry_rcu() to bypass
the RCU check.
Note that protection is not needed but RCU helper is used to
avoid data-race.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250516022759.44392-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We will get rid of RTNL from RTM_NEWROUTE and SIOCADDRT.
Then, we may be going to add a route tied to a dying nexthop.
The nexthop itself is not freed during the RCU grace period, but
if we link a route after __remove_nexthop_fib() is called for the
nexthop, the route will be leaked.
To avoid the race between IPv6 route addition under RCU vs nexthop
deletion under RTNL, let's add a dead flag and protect it and
nh->f6i_list with a spinlock.
__remove_nexthop_fib() acquires the nexthop's spinlock and sets false
to nh->dead, then calls ip6_del_rt() for the linked route one by one
without the spinlock because fib6_purge_rt() acquires it later.
While adding an IPv6 route, fib6_add() acquires the nexthop lock and
checks the dead flag just before inserting the route.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250418000443.43734-15-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The next patch adds per-nexthop spinlock which protects nh->f6i_list.
When rt->nh is not NULL, fib6_add_rt2node() will be called under the lock.
fib6_add_rt2node() could call fib6_purge_rt() for another route, which
could holds another nexthop lock.
Then, deadlock could happen between two nexthops.
Let's defer fib6_purge_rt() after fib6_add_rt2node().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/20250418000443.43734-14-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
We will get rid of RTNL from RTM_NEWROUTE and SIOCADDRT.
If the request specifies a new table ID, fib6_new_table() is
called to create a new routing table.
Two concurrent requests could specify the same table ID, so we
need a lock to protect net->ipv6.fib_table_hash[h].
Let's add a spinlock to protect the hash bucket linkage.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://patch.msgid.link/20250418000443.43734-13-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree
over and remove the historical wrapper inlines.
Conversion was done with coccinelle plus manual fixups where necessary.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Soft lockups have been observed on a cluster of Linux-based edge routers
located in a highly dynamic environment. Using the `bird` service, these
routers continuously update BGP-advertised routes due to frequently
changing nexthop destinations, while also managing significant IPv6
traffic. The lockups occur during the traversal of the multipath
circular linked-list in the `fib6_select_path` function, particularly
while iterating through the siblings in the list. The issue typically
arises when the nodes of the linked list are unexpectedly deleted
concurrently on a different core—indicated by their 'next' and
'previous' elements pointing back to the node itself and their reference
count dropping to zero. This results in an infinite loop, leading to a
soft lockup that triggers a system panic via the watchdog timer.
Apply RCU primitives in the problematic code sections to resolve the
issue. Where necessary, update the references to fib6_siblings to
annotate or use the RCU APIs.
Include a test script that reproduces the issue. The script
periodically updates the routing table while generating a heavy load
of outgoing IPv6 traffic through multiple iperf3 clients. It
consistently induces infinite soft lockups within a couple of minutes.
Kernel log:
0 [ffffbd13003e8d30] machine_kexec at ffffffff8ceaf3eb
1 [ffffbd13003e8d90] __crash_kexec at ffffffff8d0120e3
2 [ffffbd13003e8e58] panic at ffffffff8cef65d4
3 [ffffbd13003e8ed8] watchdog_timer_fn at ffffffff8d05cb03
4 [ffffbd13003e8f08] __hrtimer_run_queues at ffffffff8cfec62f
5 [ffffbd13003e8f70] hrtimer_interrupt at ffffffff8cfed756
6 [ffffbd13003e8fd0] __sysvec_apic_timer_interrupt at ffffffff8cea01af
7 [ffffbd13003e8ff0] sysvec_apic_timer_interrupt at ffffffff8df1b83d
-- <IRQ stack> --
8 [ffffbd13003d3708] asm_sysvec_apic_timer_interrupt at ffffffff8e000ecb
[exception RIP: fib6_select_path+299]
RIP: ffffffff8ddafe7b RSP: ffffbd13003d37b8 RFLAGS: 00000287
RAX: ffff975850b43600 RBX: ffff975850b40200 RCX: 0000000000000000
RDX: 000000003fffffff RSI: 0000000051d383e4 RDI: ffff975850b43618
RBP: ffffbd13003d3800 R8: 0000000000000000 R9: ffff975850b40200
R10: 0000000000000000 R11: 0000000000000000 R12: ffffbd13003d3830
R13: ffff975850b436a8 R14: ffff975850b43600 R15: 0000000000000007
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
9 [ffffbd13003d3808] ip6_pol_route at ffffffff8ddb030c
10 [ffffbd13003d3888] ip6_pol_route_input at ffffffff8ddb068c
11 [ffffbd13003d3898] fib6_rule_lookup at ffffffff8ddf02b5
12 [ffffbd13003d3928] ip6_route_input at ffffffff8ddb0f47
13 [ffffbd13003d3a18] ip6_rcv_finish_core.constprop.0 at ffffffff8dd950d0
14 [ffffbd13003d3a30] ip6_list_rcv_finish.constprop.0 at ffffffff8dd96274
15 [ffffbd13003d3a98] ip6_sublist_rcv at ffffffff8dd96474
16 [ffffbd13003d3af8] ipv6_list_rcv at ffffffff8dd96615
17 [ffffbd13003d3b60] __netif_receive_skb_list_core at ffffffff8dc16fec
18 [ffffbd13003d3be0] netif_receive_skb_list_internal at ffffffff8dc176b3
19 [ffffbd13003d3c50] napi_gro_receive at ffffffff8dc565b9
20 [ffffbd13003d3c80] ice_receive_skb at ffffffffc087e4f5 [ice]
21 [ffffbd13003d3c90] ice_clean_rx_irq at ffffffffc0881b80 [ice]
22 [ffffbd13003d3d20] ice_napi_poll at ffffffffc088232f [ice]
23 [ffffbd13003d3d80] __napi_poll at ffffffff8dc18000
24 [ffffbd13003d3db8] net_rx_action at ffffffff8dc18581
25 [ffffbd13003d3e40] __do_softirq at ffffffff8df352e9
26 [ffffbd13003d3eb0] run_ksoftirqd at ffffffff8ceffe47
27 [ffffbd13003d3ec0] smpboot_thread_fn at ffffffff8cf36a30
28 [ffffbd13003d3ee8] kthread at ffffffff8cf2b39f
29 [ffffbd13003d3f28] ret_from_fork at ffffffff8ce5fa64
30 [ffffbd13003d3f50] ret_from_fork_asm at ffffffff8ce03cbb
Fixes: 66f5d6ce53 ("ipv6: replace rwlock with rcu and spinlock in fib6_table")
Reported-by: Adrian Oliver <kernel@aoliver.ca>
Signed-off-by: Omid Ehtemam-Haghighi <omid.ehtemamhaghighi@menlosecurity.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Ido Schimmel <idosch@idosch.org>
Cc: Kuniyuki Iwashima <kuniyu@amazon.com>
Cc: Simon Horman <horms@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20241106010236.1239299-1-omid.ehtemamhaghighi@menlosecurity.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We will remove rtnl_register_module() in favour of rtnl_register_many().
rtnl_register_many() will unwind the previous successful registrations
on failure and simplify module error handling.
Let's use rtnl_register_many() instead.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014201828.91221-8-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since SLOB was removed and since
commit 6c6c47b063 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"),
it is not necessary to use call_rcu when the callback only performs
kmem_cache_free. Use kfree_rcu() directly.
The changes were made using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Link: https://patch.msgid.link/20241013201704.49576-5-Julia.Lawall@inria.fr
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Using RTNL to protect ops->fib_rules_seq reads seems a big hammer.
Writes are protected by RTNL.
We can use READ_ONCE() when reading it.
Constify 'struct net' argument of fib6_tables_seq_read() and
fib6_rules_seq_read().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20241009184405.3752829-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cross-merge networking fixes after downstream PR.
Conflicts:
drivers/net/ethernet/broadcom/bnxt/bnxt.c
1e7962114c ("bnxt_en: Restore PTP tx_avail count in case of skb_pad() error")
165f87691a ("bnxt_en: add timestamping statistics support")
No adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Cross-merge networking fixes after downstream PR.
No conflicts.
Adjacent changes:
drivers/net/ethernet/pensando/ionic/ionic_txrx.c
d9c0420999 ("ionic: Mark error paths in the data path as unlikely")
491aee894a ("ionic: fix kernel panic in XDP_TX action")
net/ipv6/ip6_fib.c
b4cb4a1391 ("net: use unrcu_pointer() helper")
b01e1c0307 ("ipv6: fix possible race in __fib6_drop_pcpu_from()")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Toke mentioned unrcu_pointer() existence, allowing
to remove some of the ugly casts we have when using
xchg() for rcu protected pointers.
Also make inet_rcv_compat const.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Toke Høiland-Jørgensen <toke@redhat.com>
Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20240604111603.45871-1-edumazet@google.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
When CONFIG_IPV6_SUBTREES is disabled, the only user is hidden, causing
a 'make W=1' warning:
net/ipv6/ip6_fib.c: In function 'fib6_add':
net/ipv6/ip6_fib.c:1388:32: error: variable 'pn' set but not used [-Werror=unused-but-set-variable]
Add another #ifdef around the variable declaration, matching the other
uses in this file.
Fixes: 66729e18df ("[IPV6] ROUTE: Make sure we have fn->leaf when adding a node on subtree.")
Link: https://lore.kernel.org/netdev/20240322131746.904943-1-arnd@kernel.org/
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240408074219.3030256-1-arnd@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
No longer hold RTNL while calling inet6_dump_fib().
Also change return value for a completed dump,
so that NLMSG_DONE can be appended to current skb,
saving one recvmsg() system call.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240329183053.644630-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a new field into struct fib_dump_filter, to let callers
tell if they use RTNL locking or RCU.
This is used in the following patch, when inet_dump_fib()
no longer holds RTNL.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Donald Hunter <donald.hunter@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Reviewed-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
FIB6 GC walks trees of fib6_tables to remove expired routes. Walking a tree
can be expensive if the number of routes in a table is big, even if most of
them are permanent. Checking routes in a separated list of routes having
expiration will avoid this potential issue.
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In some configurations, the 'iter' variable in function
fib6_repair_tree() is unused, resulting the following warning when
compiled with W=1.
net/ipv6/ip6_fib.c:1781:6: warning: variable 'iter' set but not used [-Wunused-but-set-variable]
1781 | int iter = 0;
| ^
It is unclear what is the advantage of this RT6_TRACE() macro[1], since
users can control pr_debug() in runtime, which is better than at
compilation time. pr_debug() has no overhead when disabled.
Remove the RT6_TRACE() in favor of simple pr_debug() helpers.
[1] Link: https://lore.kernel.org/all/ZZwSEJv2HgI0cD4J@gmail.com/
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240122181955.2391676-2-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
In the ipv6 system, we have some logs basically dumping the name of the
function that is being called. This is not ideal, since ftrace give us
"for free". Moreover, checkpatch is not happy when touching that code:
WARNING: Unnecessary ftrace-like logging - prefer using ftrace
Remove debug functions that only print the current function name.
Signed-off-by: Breno Leitao <leitao@debian.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20240122181955.2391676-1-leitao@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This reverts commit 3dec89b14d.
The commit has some race conditions given how expires is managed on a
fib6_info in relation to gc start, adding the entry to the gc list and
setting the timer value leading to UAF. Revert the commit and try again
in a later release.
Fixes: 3dec89b14d ("net/ipv6: Remove expired routes with a separated list of routes")
Cc: Kui-Feng Lee <thinker.li@gmail.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20231219030243.25687-1-dsahern@kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
FIB6 GC walks trees of fib6_tables to remove expired routes. Walking a tree
can be expensive if the number of routes in a table is big, even if most of
them are permanent. Checking routes in a separated list of routes having
expiration will avoid this potential issue.
Signed-off-by: Kui-Feng Lee <thinker.li@gmail.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Adopt atomic_try_cmpxchg() which is slightly more efficient.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
sock.h is pretty heavily used (5k objects rebuilt on x86 after
it's touched). We can drop the include of filter.h from it and
add a forward declaration of struct sk_filter instead.
This decreases the number of rebuilt objects when bpf.h
is touched from ~5k to ~1k.
There's a lot of missing includes this was masking. Primarily
in networking tho, this time.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com>
Acked-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
only increase fib6_sernum in net namespace after add fib6_info
successfully.
Signed-off-by: zhang kai <zhangkaiheb@126.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hangbin Liu
Kuniyuki Iwashima
Linus Torvalds
Kees Cook
Jakub Kicinski
Shigeru Yoshida
Eric Dumazet
Fernando Fernandez Mancera
Yue Haibing
Ingo Molnar
Kuniyuki Iwashima
Thomas Gleixner
Omid Ehtemam-Haghighi
Julia Lawall
Arnd Bergmann
Kunwu Chan
Kui-Feng Lee
Breno Leitao
David Ahern
zhang kai