On Thu, 13 Aug 2020 22:00:22 +0200, Prateek Sood wrote:

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: ddaf29fd9bb6 ("firmware: Free temporary page table after vmapping") Signed-off-by: Prateek Sood prsood@codeaurora.org Reviewed-by: Takashi Iwai tiwai@suse.de

Note that, for including to stable kernels properly, you'd need to put a Cc-to-stable line around the signed-off-by section in the patch itself. OTOH, you don't have to send the patch itself to stable when you submit it.

thanks,

Takashi

---

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

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