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| author | Davide Caratti <dcaratti@redhat.com> | 2023-04-20 16:59:46 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2023-05-11 23:03:26 +0900 |
| commit | 4fbefeab88c6e79753a25099d455d3d59d2946b4 (patch) | |
| tree | 6201266f3f362e28ca3e0c8c6d78140c9c0c6a6c /tools | |
| parent | 8fa6c8dad4a60cd7f715237ed408198723421e8f (diff) | |
| download | linux-4fbefeab88c6e79753a25099d455d3d59d2946b4.tar.gz | |
net/sched: sch_fq: fix integer overflow of "credit"
[ Upstream commit 7041101ff6c3073fd8f2e99920f535b111c929cb ]
if sch_fq is configured with "initial quantum" having values greater than
INT_MAX, the first assignment of "credit" does signed integer overflow to
a very negative value.
In this situation, the syzkaller script provided by Cristoph triggers the
CPU soft-lockup warning even with few sockets. It's not an infinite loop,
but "credit" wasn't probably meant to be minus 2Gb for each new flow.
Capping "initial quantum" to INT_MAX proved to fix the issue.
v2: validation of "initial quantum" is done in fq_policy, instead of open
coding in fq_change() _ suggested by Jakub Kicinski
Reported-by: Christoph Paasch <cpaasch@apple.com>
Link: https://github.com/multipath-tcp/mptcp_net-next/issues/377
Fixes: afe4fd062416 ("pkt_sched: fq: Fair Queue packet scheduler")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Davide Caratti <dcaratti@redhat.com>
Link: https://lore.kernel.org/r/7b3a3c7e36d03068707a021760a194a8eb5ad41a.1682002300.git.dcaratti@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'tools')
| -rw-r--r-- | tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json index 8acb904d1419..3593fb8f79ad 100644 --- a/tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json +++ b/tools/testing/selftests/tc-testing/tc-tests/qdiscs/fq.json @@ -115,6 +115,28 @@ ] }, { + "id": "10f7", + "name": "Create FQ with invalid initial_quantum setting", + "category": [ + "qdisc", + "fq" + ], + "plugins": { + "requires": "nsPlugin" + }, + "setup": [ + "$IP link add dev $DUMMY type dummy || /bin/true" + ], + "cmdUnderTest": "$TC qdisc add dev $DUMMY handle 1: root fq initial_quantum 0x80000000", + "expExitCode": "2", + "verifyCmd": "$TC qdisc show dev $DUMMY", + "matchPattern": "qdisc fq 1: root.*initial_quantum 2048Mb", + "matchCount": "0", + "teardown": [ + "$IP link del dev $DUMMY type dummy" + ] + }, + { "id": "9398", "name": "Create FQ with maxrate setting", "category": [ |