Commit 16c2004d9e4d ("mfd: omap-usb-tll: Allocate driver data at once")
changed the memory allocation of 'tll' to consolidate it into a single
allocation, introducing an incorrect size calculation.
In particular, the allocation for the array of pointers was converted
into a single-pointer allocation.
The memory allocation used to occur in two steps:
tll = devm_kzalloc(dev, sizeof(struct usbtll_omap), GFP_KERNEL);
tll->ch_clk = devm_kzalloc(dev, sizeof(struct clk *) * tll->nch,
GFP_KERNEL);
And it turned that into the following allocation:
tll = devm_kzalloc(dev, sizeof(*tll) + sizeof(tll->ch_clk[nch]),
GFP_KERNEL);
sizeof(tll->ch_clk[nch]) returns the size of a single pointer instead of
the expected nch pointers.
This bug went unnoticed because the allocation size was small enough to
fit within the minimum size of a memory allocation for this particular
case [1].
The complete allocation can still be done at once with the struct_size
macro, which comes in handy for structures with a trailing flexible
array.
Fix the memory allocation to obtain the original size again.
Link: https://lore.kernel.org/all/202406261121.2FFD65647@keescook/ [1]
Fixes: 16c2004d9e4d ("mfd: omap-usb-tll: Allocate driver data at once")
Reviewed-by: Kees Cook <k...@kernel.org>
Signed-off-by: Javier Carrasco <javier.carrasco.c...@gmail.com>
---
Changes in v2:
- Patch 1/2: drop (applied).
- Patch 2/2: turn into fix.
- Link to v1:
https://lore.kernel.org/r/20240620-omap-usb-tll-counted_by-v1-0-77797834b...@gmail.com
---
drivers/mfd/omap-usb-tll.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/drivers/mfd/omap-usb-tll.c b/drivers/mfd/omap-usb-tll.c
index b6303ddb013b..f68dd0281463 100644
--- a/drivers/mfd/omap-usb-tll.c
+++ b/drivers/mfd/omap-usb-tll.c
@@ -230,8 +230,7 @@ static int usbtll_omap_probe(struct platform_device *pdev)
break;
}
- tll = devm_kzalloc(dev, sizeof(*tll) + sizeof(tll->ch_clk[nch]),
- GFP_KERNEL);
+ tll = devm_kzalloc(dev, struct_size(tll, ch_clk, nch), GFP_KERNEL);
if (!tll) {
pm_runtime_put_sync(dev);
pm_runtime_disable(dev);
---
base-commit: b992b79ca8bc336fa8e2c80990b5af80ed8f36fd
change-id: 20240620-omap-usb-tll-counted_by-aac57c173018
Best regards,
--
Javier Carrasco <javier.carrasco.c...@gmail.com>
