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firmware_loader: fix memory leak for paged buffer 

commit 4965b8cd1b upstream.

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.

Fixes: ddaf29fd9b ("firmware: Free temporary page table after vmapping")
Signed-off-by: Prateek Sood <prsood@codeaurora.org>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1597957070-27185-1-git-send-email-prsood@codeaurora.org
Cc: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
5.4-rM2-2.2.x-imx-squashed
Prateek Sood 2020-08-21 02:27:50 +05:30 committed by Greg Kroah-Hartman
parent 51fe5c82c7
commit 9b6caf4ccb
2 changed files with 13 additions and 6 deletions
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2
drivers/base/firmware_loader/firmware.h
View File

@ -139,10 +139,12 @@ int assign_fw(struct firmware *fw, struct device *device,
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 */

17
drivers/base/firmware_loader/main.c
View File

@ -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