[PATCH] lib/dma-debug.c: fix memory leakage

From: miles.chen
Date: Thu Feb 22 2018 - 06:22:32 EST


From: Miles Chen <miles.chen@xxxxxxxxxxxx>

Marty reported a memory leakage introduced by commit 3aaabbf1c39e
("lib/dma-debug.c: fix incorrect pfn calculation"). Fix it
by checking the virtual address before allocating the entry.

This patch also use virt_addr_valid() instead of virt_to_page()
to check if a virtual address is linear.

Reported-by: Marty Faltesek <mfaltesek@xxxxxxxxxx>
Signed-off-by: Miles Chen <miles.chen@xxxxxxxxxxxx>
---
lib/dma-debug.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/lib/dma-debug.c b/lib/dma-debug.c
index 1b34d210452c..7f5cdc1e6b29 100644
--- a/lib/dma-debug.c
+++ b/lib/dma-debug.c
@@ -1491,12 +1491,12 @@ void debug_dma_alloc_coherent(struct device *dev, size_t size,
if (unlikely(virt == NULL))
return;

- entry = dma_entry_alloc();
- if (!entry)
+ /* handle vmalloc and linear addresses */
+ if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
return;

- /* handle vmalloc and linear addresses */
- if (!is_vmalloc_addr(virt) && !virt_to_page(virt))
+ entry = dma_entry_alloc();
+ if (!entry)
return;

entry->type = dma_debug_coherent;
@@ -1528,7 +1528,7 @@ void debug_dma_free_coherent(struct device *dev, size_t size,
};

/* handle vmalloc and linear addresses */
- if (!is_vmalloc_addr(virt) && !virt_to_page(virt))
+ if (!is_vmalloc_addr(virt) && !virt_addr_valid(virt))
return;

if (is_vmalloc_addr(virt))
--
2.12.5