[<prev] [next>] [thread-next>] [day] [month] [year] [list]
Message-ID: <20250518174531.1287128-1-dominik.grzegorzek@oracle.com>
Date: Sun, 18 May 2025 19:45:31 +0200
From: Dominik Grzegorzek <dominik.grzegorzek@...cle.com>
To: Steffen Klassert <steffen.klassert@...unet.com>,
Daniel Jordan <daniel.m.jordan@...cle.com>
Cc: dominik.grzegorzek@...cle.com, Herbert Xu <herbert@...dor.apana.org.au>,
Chen Ridong <chenridong@...wei.com>,
linux-crypto@...r.kernel.org (open list:PADATA PARALLEL EXECUTION MECHANISM),
linux-kernel@...r.kernel.org (open list:PADATA PARALLEL EXECUTION MECHANISM)
Subject: [PATCH] padata: do not leak refcount in reorder_work
A recent patch that addressed a UAF introduced a reference count leak:
the parallel_data refcount is incremented unconditionally, regardless
of the return value of queue_work(). If the work item is already queued,
the incremented refcount is never decremented.
Fix this by checking the return value of queue_work() and decrementing
the refcount when necessary.
Resolves:
Unreferenced object 0xffff9d9f421e3d80 (size 192):
comm "cryptomgr_probe", pid 157, jiffies 4294694003
hex dump (first 32 bytes):
80 8b cf 41 9f 9d ff ff b8 97 e0 89 ff ff ff ff ...A............
d0 97 e0 89 ff ff ff ff 19 00 00 00 1f 88 23 00 ..............#.
backtrace (crc 838fb36):
__kmalloc_cache_noprof+0x284/0x320
padata_alloc_pd+0x20/0x1e0
padata_alloc_shell+0x3b/0xa0
0xffffffffc040a54d
cryptomgr_probe+0x43/0xc0
kthread+0xf6/0x1f0
ret_from_fork+0x2f/0x50
ret_from_fork_asm+0x1a/0x30
Fixes: dd7d37ccf6b1 ("padata: avoid UAF for reorder_work")
Signed-off-by: Dominik Grzegorzek <dominik.grzegorzek@...cle.com>
---
kernel/padata.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/padata.c b/kernel/padata.c
index b3d4eacc4f5d..7eee94166357 100644
--- a/kernel/padata.c
+++ b/kernel/padata.c
@@ -358,7 +358,8 @@ static void padata_reorder(struct parallel_data *pd)
* To avoid UAF issue, add pd ref here, and put pd ref after reorder_work finish.
*/
padata_get_pd(pd);
- queue_work(pinst->serial_wq, &pd->reorder_work);
+ if (!queue_work(pinst->serial_wq, &pd->reorder_work))
+ padata_put_pd(pd);
}
}
--
2.43.0
Powered by blists - more mailing lists