diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2014-11-06 19:23:39 +0300 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2015-01-05 16:48:39 +0300 |
| commit | eb6719481dd5febd5b04061472ad21028e05e2e4 (patch) | |
| tree | 2c9e058db1fecd75ff2a533872db21c6fb6c2ac3 /drivers/misc/genwqe | |
| parent | 4fb1f2f7fd55ee5bc3c33abc46d6f359d7e1fc8c (diff) | |
| download | linux-eb6719481dd5febd5b04061472ad21028e05e2e4.tar.xz | |
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>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'drivers/misc/genwqe')
| -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 62cc6bb3f62e..ded1c2507d3d 100644 --- a/drivers/misc/genwqe/card_utils.c +++ b/drivers/misc/genwqe/card_utils.c @@ -580,6 +580,8 @@ 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) { |