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| author | Jakub Kicinski <kuba@kernel.org> | 2026-02-26 06:17:12 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-02-26 06:17:12 +0300 |
| commit | 77da71283cad9446d4160531accfb80ebf3d1cbb (patch) | |
| tree | f786604e7d1484b584ed1471f5e9755d711c0d11 /tools | |
| parent | f975a0955276579e2176a134366ed586071c7c6a (diff) | |
| parent | 58f8ef625e23a607f4a89758d6b328a2701f7354 (diff) | |
| download | linux-77da71283cad9446d4160531accfb80ebf3d1cbb.tar.xz | |
Merge branch 'team-fix-reference-count-leak-when-changing-port-netns'
Ido Schimmel says:
====================
team: Fix reference count leak when changing port netns
Patch #1 fixes a reference count leak that was reported by syzkaller.
The leak happens when a net device that is member in a team is changing
netns. The fix is to align the team driver with the bond driver and have
it suppress NETDEV_CHANGEMTU events for a net device that is being
unregistered.
Without this change, the NETDEV_CHANGEMTU event causes inetdev_event()
to recreate an inet device for this net device in its original netns,
after it was previously destroyed upon NETDEV_UNREGISTER. Later on, when
inetdev_event() receives a NETDEV_REGISTER event for this net device in
the new nents, it simply leaks the reference:
case NETDEV_REGISTER:
pr_debug("%s: bug\n", __func__);
RCU_INIT_POINTER(dev->ip_ptr, NULL);
break;
addrconf_notify() handles this differently and reuses the existing inet6
device if one exists when a NETDEV_REGISTER event is received. This
creates a different problem where it is possible for a net device to
reference an inet6 device that was created in a previous netns.
A more generic fix that we can try in net-next is to revert the changes
in the bond and team drivers and instead have IPv4 and IPv6 destroy and
recreate an inet device if one already exists upon NETDEV_REGISTER.
Patch #2 adds a selftest that passes with the fix and hangs without it.
====================
Link: https://patch.msgid.link/20260224125709.317574-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/drivers/net/team/Makefile | 1 | ||||
| -rwxr-xr-x | tools/testing/selftests/drivers/net/team/refleak.sh | 17 |
2 files changed, 18 insertions, 0 deletions
diff --git a/tools/testing/selftests/drivers/net/team/Makefile b/tools/testing/selftests/drivers/net/team/Makefile index 1340b3df9c31..45a3e7ad3dcb 100644 --- a/tools/testing/selftests/drivers/net/team/Makefile +++ b/tools/testing/selftests/drivers/net/team/Makefile @@ -5,6 +5,7 @@ TEST_PROGS := \ dev_addr_lists.sh \ options.sh \ propagation.sh \ + refleak.sh \ # end of TEST_PROGS TEST_INCLUDES := \ diff --git a/tools/testing/selftests/drivers/net/team/refleak.sh b/tools/testing/selftests/drivers/net/team/refleak.sh new file mode 100755 index 000000000000..ef08213ab964 --- /dev/null +++ b/tools/testing/selftests/drivers/net/team/refleak.sh @@ -0,0 +1,17 @@ +#!/bin/bash +# SPDX-License-Identifier: GPL-2.0 +# shellcheck disable=SC2154 + +lib_dir=$(dirname "$0") +source "$lib_dir"/../../../net/lib.sh + +trap cleanup_all_ns EXIT + +# Test that there is no reference count leak and that dummy1 can be deleted. +# https://lore.kernel.org/netdev/4d69abe1-ca8d-4f0b-bcf8-13899b211e57@I-love.SAKURA.ne.jp/ +setup_ns ns1 ns2 +ip -n "$ns1" link add name team1 type team +ip -n "$ns1" link add name dummy1 mtu 1499 type dummy +ip -n "$ns1" link set dev dummy1 master team1 +ip -n "$ns1" link set dev dummy1 netns "$ns2" +ip -n "$ns2" link del dev dummy1 |