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author | Daniel Vacek <neelx@redhat.com> | 2024-04-02 20:41:30 +0800 |
---|---|---|
committer | openeuler-sync-bot <openeuler.syncbot@gmail.com> | 2024-04-16 10:43:25 +0800 |
commit | e0192117d86395e374bad7b6d9449c932246b985 (patch) | |
tree | 34efdb5cde68151b07eb19a67231de5a777c67ad | |
parent | da54f8bd03aa8390f275595b6666e793257c0b07 (diff) | |
download | openEuler-kernel-e0192117d86395e374bad7b6d9449c932246b985.tar.gz |
IB/ipoib: Fix mcast list locking
stable inclusion
from stable-v5.10.210
commit ac2630fd3c90ffec34a0bfc4d413668538b0e8f2
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I96G8W
CVE: CVE-2023-52587
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=ac2630fd3c90ffec34a0bfc4d413668538b0e8f2
--------------------------------
[ Upstream commit 4f973e211b3b1c6d36f7c6a19239d258856749f9 ]
Releasing the `priv->lock` while iterating the `priv->multicast_list` in
`ipoib_mcast_join_task()` opens a window for `ipoib_mcast_dev_flush()` to
remove the items while in the middle of iteration. If the mcast is removed
while the lock was dropped, the for loop spins forever resulting in a hard
lockup (as was reported on RHEL 4.18.0-372.75.1.el8_6 kernel):
Task A (kworker/u72:2 below) | Task B (kworker/u72:0 below)
-----------------------------------+-----------------------------------
ipoib_mcast_join_task(work) | ipoib_ib_dev_flush_light(work)
spin_lock_irq(&priv->lock) | __ipoib_ib_dev_flush(priv, ...)
list_for_each_entry(mcast, | ipoib_mcast_dev_flush(dev = priv->dev)
&priv->multicast_list, list) |
ipoib_mcast_join(dev, mcast) |
spin_unlock_irq(&priv->lock) |
| spin_lock_irqsave(&priv->lock, flags)
| list_for_each_entry_safe(mcast, tmcast,
| &priv->multicast_list, list)
| list_del(&mcast->list);
| list_add_tail(&mcast->list, &remove_list)
| spin_unlock_irqrestore(&priv->lock, flags)
spin_lock_irq(&priv->lock) |
| ipoib_mcast_remove_list(&remove_list)
(Here, `mcast` is no longer on the | list_for_each_entry_safe(mcast, tmcast,
`priv->multicast_list` and we keep | remove_list, list)
spinning on the `remove_list` of | >>> wait_for_completion(&mcast->done)
the other thread which is blocked |
and the list is still valid on |
it's stack.)
Fix this by keeping the lock held and changing to GFP_ATOMIC to prevent
eventual sleeps.
Unfortunately we could not reproduce the lockup and confirm this fix but
based on the code review I think this fix should address such lockups.
crash> bc 31
PID: 747 TASK: ff1c6a1a007e8000 CPU: 31 COMMAND: "kworker/u72:2"
[exception RIP: ipoib_mcast_join_task+0x1b1]
RIP: ffffffffc0944ac1 RSP: ff646f199a8c7e00 RFLAGS: 00000002
RAX: 0000000000000000 RBX: ff1c6a1a04dc82f8 RCX: 0000000000000000
work (&priv->mcast_task{,.work})
RDX: ff1c6a192d60ac68 RSI: 0000000000000286 RDI: ff1c6a1a04dc8000
&mcast->list
RBP: ff646f199a8c7e90 R8: ff1c699980019420 R9: ff1c6a1920c9a000
R10: ff646f199a8c7e00 R11: ff1c6a191a7d9800 R12: ff1c6a192d60ac00
mcast
R13: ff1c6a1d82200000 R14: ff1c6a1a04dc8000 R15: ff1c6a1a04dc82d8
dev priv (&priv->lock) &priv->multicast_list (aka head)
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Yu Liao <liaoyu15@huawei.com>
(cherry picked from commit 13f968e187b2e515e9c7e36ccac95e8f47037ab9)
-rw-r--r-- | drivers/infiniband/ulp/ipoib/ipoib_multicast.c | 6 |
1 files changed, 1 insertions, 5 deletions
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c index 5633809dc61e90..e009123c703b08 100644 --- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c +++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c @@ -542,21 +542,17 @@ static int ipoib_mcast_join(struct net_device *dev, struct ipoib_mcast *mcast) /* SM supports sendonly-fullmember, otherwise fallback to full-member */ rec.join_state = SENDONLY_FULLMEMBER_JOIN; } - spin_unlock_irq(&priv->lock); multicast = ib_sa_join_multicast(&ipoib_sa_client, priv->ca, priv->port, - &rec, comp_mask, GFP_KERNEL, + &rec, comp_mask, GFP_ATOMIC, ipoib_mcast_join_complete, mcast); - spin_lock_irq(&priv->lock); if (IS_ERR(multicast)) { ret = PTR_ERR(multicast); ipoib_warn(priv, "ib_sa_join_multicast failed, status %d\n", ret); /* Requeue this join task with a backoff delay */ __ipoib_mcast_schedule_join_thread(priv, mcast, 1); clear_bit(IPOIB_MCAST_FLAG_BUSY, &mcast->flags); - spin_unlock_irq(&priv->lock); complete(&mcast->done); - spin_lock_irq(&priv->lock); return ret; } return 0; |