From: Colin Ian King <colin.king@xxxxxxxxxxxxx>
In the case that shm->pages fails to allocate, the current exit
error path will try to put_page on a null shm->pages and cause
a null pointer dereference when accessing shm->pages[n]. Fix this
by only performing the put_page and kfree on shm->pages if it
is not null.
Detected by CoverityScan, CID#1463283 ("Dereference after null check")
Fixes: 033ddf12bcf5 ("tee: add register user memory")
Signed-off-by: Colin Ian King <colin.king@xxxxxxxxxxxxx>
---
drivers/tee/tee_shm.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 13b4de1157c7..6890c8aaef8c 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -335,9 +335,11 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
idr_remove(&teedev->idr, shm->id);
mutex_unlock(&teedev->mutex);
}
- for (n = 0; n < shm->num_pages; n++)
- put_page(shm->pages[n]);
- kfree(shm->pages);
+ if (shm->pages) {
+ for (n = 0; n < shm->num_pages; n++)
+ put_page(shm->pages[n]);
+ kfree(shm->pages);
+ }
}
kfree(shm);
teedev_ctx_put(ctx);
--
2.14.1
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