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authorIan Abbott <abbotti@mev.co.uk>2014-11-06 16:23:39 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-11-07 10:26:46 -0800
commitcf35d6e0475982667b0d2d318fb27be4b8849827 (patch)
tree45f0b776d4f9497e793cbfa1f0afe59e85606004
parent965ab29ba09d75056a6c9b0f707cd1c2cc91188f (diff)
downloadlinux-cf35d6e0475982667b0d2d318fb27be4b8849827.tar.bz2
misc: genwqe: check for error from get_user_pages_fast()
`genwqe_user_vmap()` calls `get_user_pages_fast()` and if the return value is less than the number of pages requested, it frees the pages and returns an error (`-EFAULT`). However, it fails to consider a negative error return value from `get_user_pages_fast()`. In that case, the test `if (rc < m->nr_pages)` will be false (due to promotion of `rc` to a large `unsigned int`) and the code will continue on to call `genwqe_map_pages()` with an invalid list of page pointers. Fix it by bailing out if `get_user_pages_fast()` returns a negative error value. Signed-off-by: Ian Abbott <abbotti@mev.co.uk> Cc: <stable@vger.kernel.org> # 3.14.x # 3.15.x # 3.16.x # 3.17.x Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/misc/genwqe/card_utils.c2
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c
index 7cb3b7e41739..1ca94e6fa8fb 100644
--- a/drivers/misc/genwqe/card_utils.c
+++ b/drivers/misc/genwqe/card_utils.c
@@ -590,6 +590,8 @@ int genwqe_user_vmap(struct genwqe_dev *cd, struct dma_mapping *m, void *uaddr,
m->nr_pages,
1, /* write by caller */
m->page_list); /* ptrs to pages */
+ if (rc < 0)
+ goto fail_get_user_pages;
/* assumption: get_user_pages can be killed by signals. */
if (rc < m->nr_pages) {