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authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-01-25 11:19:46 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-01-25 11:19:46 +0100
commit0f8b29fabacbcf0e617896c7ea832b7ea2ef2406 (patch)
tree0187f2baef24b5d78d94aecc7057356a36c58b5d /drivers/net/ppp
parente71a8d5cf4b4f274740e31b601216071e2a11afa (diff)
parent6ee1d745b7c9fd573fba142a2efdad76a9f1cb04 (diff)
Merge 5.11-rc5 into tty-next
We need the fixes in here and this resolves a merge issue in drivers/tty/tty_io.c Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/net/ppp')
-rw-r--r--drivers/net/ppp/ppp_generic.c12
1 files changed, 9 insertions, 3 deletions
diff --git a/drivers/net/ppp/ppp_generic.c b/drivers/net/ppp/ppp_generic.c
index 09c27f7773f9..d445ecb1d0c7 100644
--- a/drivers/net/ppp/ppp_generic.c
+++ b/drivers/net/ppp/ppp_generic.c
@@ -623,6 +623,7 @@ static int ppp_bridge_channels(struct channel *pch, struct channel *pchb)
write_unlock_bh(&pch->upl);
return -EALREADY;
}
+ refcount_inc(&pchb->file.refcnt);
rcu_assign_pointer(pch->bridge, pchb);
write_unlock_bh(&pch->upl);
@@ -632,19 +633,24 @@ static int ppp_bridge_channels(struct channel *pch, struct channel *pchb)
write_unlock_bh(&pchb->upl);
goto err_unset;
}
+ refcount_inc(&pch->file.refcnt);
rcu_assign_pointer(pchb->bridge, pch);
write_unlock_bh(&pchb->upl);
- refcount_inc(&pch->file.refcnt);
- refcount_inc(&pchb->file.refcnt);
-
return 0;
err_unset:
write_lock_bh(&pch->upl);
+ /* Re-read pch->bridge with upl held in case it was modified concurrently */
+ pchb = rcu_dereference_protected(pch->bridge, lockdep_is_held(&pch->upl));
RCU_INIT_POINTER(pch->bridge, NULL);
write_unlock_bh(&pch->upl);
synchronize_rcu();
+
+ if (pchb)
+ if (refcount_dec_and_test(&pchb->file.refcnt))
+ ppp_destroy_channel(pchb);
+
return -EALREADY;
}