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Subject[PATCH] firmware_loader: fix memory leak for paged buffer
Date
vfree() is being called on paged buffer allocated
using alloc_page() and mapped using vmap().

Freeing of pages in vfree() relies on nr_pages of
struct vm_struct. vmap() does not update nr_pages.
It can lead to memory leaks.

Signed-off-by: Prateek Sood <prsood@codeaurora.org>
---
drivers/base/firmware_loader/firmware.h | 2 ++
drivers/base/firmware_loader/main.c | 17 +++++++++++------
2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/drivers/base/firmware_loader/firmware.h b/drivers/base/firmware_loader/firmware.h
index 933e2192..d08efc7 100644
--- a/drivers/base/firmware_loader/firmware.h
+++ b/drivers/base/firmware_loader/firmware.h
@@ -142,10 +142,12 @@ static inline void fw_state_done(struct fw_priv *fw_priv)
void fw_free_paged_buf(struct fw_priv *fw_priv);
int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed);
int fw_map_paged_buf(struct fw_priv *fw_priv);
+bool fw_is_paged_buf(struct fw_priv *fw_priv);
#else
static inline void fw_free_paged_buf(struct fw_priv *fw_priv) {}
static inline int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { return -ENXIO; }
static inline int fw_map_paged_buf(struct fw_priv *fw_priv) { return -ENXIO; }
+static inline bool fw_is_paged_buf(struct fw_priv *fw_priv) { return false; }
#endif

#endif /* __FIRMWARE_LOADER_H */
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c
index ca871b1..36bf455 100644
--- a/drivers/base/firmware_loader/main.c
+++ b/drivers/base/firmware_loader/main.c
@@ -252,9 +252,11 @@ static void __free_fw_priv(struct kref *ref)
list_del(&fw_priv->list);
spin_unlock(&fwc->lock);

- fw_free_paged_buf(fw_priv); /* free leftover pages */
- if (!fw_priv->allocated_size)
+ if (fw_is_paged_buf(fw_priv))
+ fw_free_paged_buf(fw_priv);
+ else if (!fw_priv->allocated_size)
vfree(fw_priv->data);
+
kfree_const(fw_priv->fw_name);
kfree(fw_priv);
}
@@ -268,6 +270,11 @@ static void free_fw_priv(struct fw_priv *fw_priv)
}

#ifdef CONFIG_FW_LOADER_PAGED_BUF
+bool fw_is_paged_buf(struct fw_priv *fw_priv)
+{
+ return fw_priv->is_paged_buf;
+}
+
void fw_free_paged_buf(struct fw_priv *fw_priv)
{
int i;
@@ -275,6 +282,8 @@ void fw_free_paged_buf(struct fw_priv *fw_priv)
if (!fw_priv->pages)
return;

+ vunmap(fw_priv->data);
+
for (i = 0; i < fw_priv->nr_pages; i++)
__free_page(fw_priv->pages[i]);
kvfree(fw_priv->pages);
@@ -328,10 +337,6 @@ int fw_map_paged_buf(struct fw_priv *fw_priv)
if (!fw_priv->data)
return -ENOMEM;

- /* page table is no longer needed after mapping, let's free */
- kvfree(fw_priv->pages);
- fw_priv->pages = NULL;
-
return 0;
}
#endif
--
Qualcomm India Private Limited, on behalf of Qualcomm Innovation Center, Inc.,
is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.
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