Re: [alsa-devel] [PATCH 1/5] lightnvm: Fix uninitialized pointer in nvm_remove_tgt()

Hi Matias,

On Wed, May 29, 2019 at 10:08 AM Matias Bjørling mb@lightnvm.io wrote:

On 5/28/19 4:24 PM, Geert Uytterhoeven wrote:

...

With gcc 4.1:

 drivers/lightnvm/core.c: In function ‘nvm_remove_tgt’:
 drivers/lightnvm/core.c:510: warning: ‘t’ is used uninitialized in this function

Indeed, if no NVM devices have been registered, t will be an uninitialized pointer, and may be dereferenced later. A call to nvm_remove_tgt() can be triggered from userspace by issuing the NVM_DEV_REMOVE ioctl on the lightnvm control device.

Fix this by preinitializing t to NULL.

Fixes: 843f2edbdde085b4 ("lightnvm: do not remove instance under global lock") Signed-off-by: Geert Uytterhoeven geert@linux-m68k.org

---

drivers/lightnvm/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/lightnvm/core.c b/drivers/lightnvm/core.c index 0df7454832efe082..aa017f48eb8c588c 100644 --- a/drivers/lightnvm/core.c +++ b/drivers/lightnvm/core.c @@ -492,7 +492,7 @@ static void __nvm_remove_target(struct nvm_target *t, bool graceful) */ static int nvm_remove_tgt(struct nvm_ioctl_remove *remove) {

• struct nvm_target *t;
  

• struct nvm_target *t = NULL;
  struct nvm_dev *dev;
  
  down_read(&nvm_lock);
  
  

Thanks Geert. Would you like me to carry the patch?

Yes please. Thanks!

Gr{oetje,eeting}s,

Geert