scsi: elx: efct: adjust error handling inside efct_hw_setup_io
Commit Message
IO and WQE buffers are allocated once per HW and can be reused later. If
WQE buffers allocation fails then the whole allocation is marked as failed
but already created IO array internal objects are not freed. hw->io is
freed but not nullified in that specific case - it may become a problem
later as efct_hw_setup_io() is supposed to be reusable for the same HW.
While at it, use kcalloc instead of kmalloc_array/memset-zero combination
and get rid of some needless NULL assignments: nullifying hw->io[i]
elements just before freeing hw->io is not really useful.
Found by Linux Verification Center (linuxtesting.org).
Fixes: 4df84e846624 ("scsi: elx: efct: Driver initialization routines")
Cc: stable@vger.kernel.org
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
---
drivers/scsi/elx/efct/efct_hw.c | 14 ++++----------
1 file changed, 4 insertions(+), 10 deletions(-)
Comments
On Thu, Feb 08, 2024 at 12:36:57PM +0300, Fedor Pchelkin wrote:
> IO and WQE buffers are allocated once per HW and can be reused later. If
> WQE buffers allocation fails then the whole allocation is marked as failed
> but already created IO array internal objects are not freed. hw->io is
> freed but not nullified in that specific case - it may become a problem
> later as efct_hw_setup_io() is supposed to be reusable for the same HW.
>
> While at it, use kcalloc instead of kmalloc_array/memset-zero combination
> and get rid of some needless NULL assignments: nullifying hw->io[i]
> elements just before freeing hw->io is not really useful.
>
> Found by Linux Verification Center (linuxtesting.org).
>
> Fixes: 4df84e846624 ("scsi: elx: efct: Driver initialization routines")
> Cc: stable@vger.kernel.org
> Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
The patch looks okay. Though I think this funktion leaks all over the
place memory as soon we take the error path. Could you also prepare
a fix for these path while you are at it?
Thanks!
Daniel
@@ -487,12 +487,10 @@ efct_hw_setup_io(struct efct_hw *hw)
struct efct *efct = hw->os;
if (!hw->io) {
- hw->io = kmalloc_array(hw->config.n_io, sizeof(io), GFP_KERNEL);
+ hw->io = kcalloc(hw->config.n_io, sizeof(io), GFP_KERNEL);
if (!hw->io)
return -ENOMEM;
- memset(hw->io, 0, hw->config.n_io * sizeof(io));
-
for (i = 0; i < hw->config.n_io; i++) {
hw->io[i] = kzalloc(sizeof(*io), GFP_KERNEL);
if (!hw->io[i])
@@ -502,10 +500,8 @@ efct_hw_setup_io(struct efct_hw *hw)
/* Create WQE buffs for IO */
hw->wqe_buffs = kzalloc((hw->config.n_io * hw->sli.wqe_size),
GFP_KERNEL);
- if (!hw->wqe_buffs) {
- kfree(hw->io);
- return -ENOMEM;
- }
+ if (!hw->wqe_buffs)
+ goto error;
} else {
/* re-use existing IOs, including SGLs */
@@ -586,10 +582,8 @@ efct_hw_setup_io(struct efct_hw *hw)
return 0;
error:
- for (i = 0; i < hw->config.n_io && hw->io[i]; i++) {
+ for (i = 0; i < hw->config.n_io && hw->io[i]; i++)
kfree(hw->io[i]);
- hw->io[i] = NULL;
- }
kfree(hw->io);
hw->io = NULL;