[PATCH] scsi: aacraid: Prevent premature freeing and improve memory allocation checks for fsa_dev
From: Riyan Dhiman
Date: Tue Sep 03 2024 - 13:20:05 EST
Refactor the allocation and freeing sequence of `fsa_dev` to ensure
that memory is not prematurely freed, which could lead to use-after-free errors
or undefined behavior.
Changes:
- Modified the order of memory operations by allocating new memory for fsa_dev
first and checking for success before freeing the old fsa_dev pointer.
- Updated the error handling to ensure -ENOMEM is returned if allocation fails,
preserving the existing valid memory.
Signed-off-by: Riyan Dhiman <riyandhiman14@xxxxxxxxx>
---
drivers/scsi/aacraid/aachba.c | 14 +++++---------
1 file changed, 5 insertions(+), 9 deletions(-)
diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index b22857c6f3f4..f3fc9b622aee 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -490,18 +490,14 @@ int aac_get_containers(struct aac_dev *dev)
if (dev->fsa_dev == NULL ||
dev->maximum_num_containers != maximum_num_containers) {
- fsa_dev_ptr = dev->fsa_dev;
-
- dev->fsa_dev = kcalloc(maximum_num_containers,
+ fsa_dev_ptr = kcalloc(maximum_num_containers,
sizeof(*fsa_dev_ptr), GFP_KERNEL);
-
- kfree(fsa_dev_ptr);
- fsa_dev_ptr = NULL;
-
-
- if (!dev->fsa_dev)
+ if(!fsa_dev_ptr)
return -ENOMEM;
+ kfree(dev->fsa_dev);
+ dev->fsa_dev = fsa_dev_ptr;
+
dev->maximum_num_containers = maximum_num_containers;
}
for (index = 0; index < dev->maximum_num_containers; index++) {
--
2.46.0