[PATCH] misc: fastrpc: Fix dma_buf object leak in fastrpc_map_lookup

[PATCH] misc: fastrpc: Fix dma_buf object leak in fastrpc_map_lookup

[Junhao Xie]

In fastrpc_map_lookup, dma_buf_get is called to obtain a reference to
the dma_buf for comparison purposes. However, this reference is never
released when the function returns, leading to a dma_buf memory leak.

Fix this by adding dma_buf_put before returning from the function,
ensuring that the temporarily acquired reference is properly released
regardless of whether a matching map is found.

Fixes: 9031626ade38 ("misc: fastrpc: Fix fastrpc_map_lookup operation")
Cc: stable@kernel.org
Signed-off-by: Junhao Xie <bigfoot@radxa.com>
Tested-by: Xilin Wu <sophon@radxa.com>
---
 drivers/misc/fastrpc.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/misc/fastrpc.c b/drivers/misc/fastrpc.c
index 621bce7e101c1..ee652ef01534a 100644
--- a/drivers/misc/fastrpc.c
+++ b/drivers/misc/fastrpc.c
@@ -381,6 +381,8 @@ static int fastrpc_map_lookup(struct fastrpc_user *fl, int fd,
 	}
 	spin_unlock(&fl->lock);
 
+	dma_buf_put(buf);
+
 	return ret;
 }
 
-- 
2.50.1

Re: [PATCH] misc: fastrpc: Fix dma_buf object leak in fastrpc_map_lookup

[kernel test robot]

Hi,

Thanks for your patch.

FYI: kernel test robot notices the stable kernel rule is not satisfied.

The check is based on https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html#option-1

Rule: add the tag "Cc: stable@vger.kernel.org" in the sign-off area to have the patch automatically included in the stable tree.
Subject: [PATCH] misc: fastrpc: Fix dma_buf object leak in fastrpc_map_lookup
Link: https://lore.kernel.org/stable/48B368FB4C7007A7%2B20251017083906.3259343-1-bigfoot%40radxa.com

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