diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2014-11-06 16:23:39 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-16 06:59:31 -0800 |
| commit | 7de4a0e7fe4390dfc3b42c1fdcd53104758cc33c (patch) | |
| tree | 24b8f0754d5830f69b8ac36a00158b675f67936c | |
| parent | e9820ed9a247ea5b018d71bf0af750acf0c02451 (diff) | |
misc: genwqe: check for error from get_user_pages_fast()
commit cf35d6e0475982667b0d2d318fb27be4b8849827 upstream.
`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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/misc/genwqe/card_utils.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/drivers/misc/genwqe/card_utils.c b/drivers/misc/genwqe/card_utils.c index 6b1a6ef9f1a8..0c3a64708409 100644 --- a/drivers/misc/genwqe/card_utils.c +++ b/drivers/misc/genwqe/card_utils.c @@ -490,6 +490,8 @@ 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) { |