[PATCH 2/3] nouveau: sanitise NOUVEAU_LIBDRM_*_LIMIT_PERCENT input

[Emil Velikov]

Current handling relies on atoi which does not detect errors
additionally, any integer value will be considered as a valid
percent.

Resolve that by using strtol and limiting the value within
the 5-100 (percent) range.

Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
---
 nouveau/nouveau.c | 24 +++++++++++++++---------
 1 file changed, 15 insertions(+), 9 deletions(-)

diff --git a/nouveau/nouveau.c b/nouveau/nouveau.c
index d6013db..06cd804 100644
--- a/nouveau/nouveau.c
+++ b/nouveau/nouveau.c
@@ -76,7 +76,7 @@ nouveau_device_wrap(int fd, int close, struct nouveau_device 
**pdev)
        struct nouveau_device *dev = &nvdev->base;
        uint64_t chipset, vram, gart, bousage;
        drmVersionPtr ver;
-       int ret;
+       int ret, limit;
        char *tmp;

 #ifdef DEBUG
@@ -121,16 +121,22 @@ nouveau_device_wrap(int fd, int close, struct 
nouveau_device **pdev)

        nvdev->close = close;

+       nvdev->vram_limit_percent = 80;
        tmp = getenv("NOUVEAU_LIBDRM_VRAM_LIMIT_PERCENT");
-       if (tmp)
-               nvdev->vram_limit_percent = atoi(tmp);
-       else
-               nvdev->vram_limit_percent = 80;
+       if (tmp) {
+               limit = strtol(tmp, NULL, 10);
+               if (limit >= 5 && limit <= 100)
+                       nvdev->vram_limit_percent = limit;
+       }
+
+       nvdev->gart_limit_percent = 80;
        tmp = getenv("NOUVEAU_LIBDRM_GART_LIMIT_PERCENT");
-       if (tmp)
-               nvdev->gart_limit_percent = atoi(tmp);
-       else
-               nvdev->gart_limit_percent = 80;
+       if (tmp) {
+               limit = strtol(tmp, NULL, 10);
+               if (limit >= 5 && limit <= 100)
+                       nvdev->gart_limit_percent = limit;
+       }
+
        DRMINITLISTHEAD(&nvdev->bo_list);
        nvdev->base.object.oclass = NOUVEAU_DEVICE_CLASS;
        nvdev->base.lib_version = 0x01000000;
-- 
1.9.0