From: Nicholas Piggin <npiggin@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Haren Myneni <haren@linux.ibm.com>,
Sachin Sant <sachinp@linux.ibm.com>,
Nicholas Piggin <npiggin@gmail.com>
Subject: [PATCH] powerpc/64s: Fix VAS mm use after free
Date: Wed, 7 Jun 2023 20:10:24 +1000 [thread overview]
Message-ID: <20230607101024.14559-1-npiggin@gmail.com> (raw)
The refcount on mm is dropped before the coprocessor is detached.
Reported-by: Sachin Sant <sachinp@linux.ibm.com>
Fixes: 7bc6f71bdff5f ("powerpc/vas: Define and use common vas_window struct")
Fixes: b22f2d88e435c ("powerpc/pseries/vas: Integrate API with open/close windows")
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
How's this for fixing your vas_deallocate_window warning at
radix_tlb.c:991 ?
I added a few new warnings in the TLB flush code recently which is
why these new warns are showing up.
Thanks,
Nick
arch/powerpc/platforms/powernv/vas-window.c | 2 +-
arch/powerpc/platforms/pseries/vas.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/platforms/powernv/vas-window.c b/arch/powerpc/platforms/powernv/vas-window.c
index 0072682531d8..b664838008c1 100644
--- a/arch/powerpc/platforms/powernv/vas-window.c
+++ b/arch/powerpc/platforms/powernv/vas-window.c
@@ -1310,8 +1310,8 @@ int vas_win_close(struct vas_window *vwin)
/* if send window, drop reference to matching receive window */
if (window->tx_win) {
if (window->user_win) {
- put_vas_user_win_ref(&vwin->task_ref);
mm_context_remove_vas_window(vwin->task_ref.mm);
+ put_vas_user_win_ref(&vwin->task_ref);
}
put_rx_win(window->rxwin);
}
diff --git a/arch/powerpc/platforms/pseries/vas.c b/arch/powerpc/platforms/pseries/vas.c
index 513180467562..9a44a98ba342 100644
--- a/arch/powerpc/platforms/pseries/vas.c
+++ b/arch/powerpc/platforms/pseries/vas.c
@@ -507,8 +507,8 @@ static int vas_deallocate_window(struct vas_window *vwin)
vascaps[win->win_type].nr_open_windows--;
mutex_unlock(&vas_pseries_mutex);
- put_vas_user_win_ref(&vwin->task_ref);
mm_context_remove_vas_window(vwin->task_ref.mm);
+ put_vas_user_win_ref(&vwin->task_ref);
kfree(win);
return 0;
--
2.40.1
next reply other threads:[~2023-06-07 10:11 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-07 10:10 Nicholas Piggin [this message]
2023-06-07 10:42 ` [PATCH] powerpc/64s: Fix VAS mm use after free Sachin Sant
2023-07-03 5:26 ` Michael Ellerman
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