On 16/11/24 01:00, Ira Weiny wrote:
Suraj Sonawane wrote:
Fix an issue detected by syzbot with KASAN:
BUG: KASAN: vmalloc-out-of-bounds in cmd_to_func drivers/acpi/nfit/
core.c:416 [inline]
BUG: KASAN: vmalloc-out-of-bounds in acpi_nfit_ctl+0x20e8/0x24a0
drivers/acpi/nfit/core.c:459
The issue occurs in cmd_to_func when the call_pkg->nd_reserved2
array is accessed without verifying that call_pkg points to a buffer
that is appropriately sized as a struct nd_cmd_pkg. This can lead
to out-of-bounds access and undefined behavior if the buffer does not
have sufficient space.
To address this, a check was added in acpi_nfit_ctl() to ensure that
buf is not NULL and that buf_len is less than sizeof(*call_pkg)
before accessing it. This ensures safe access to the members of
call_pkg, including the nd_reserved2 array.
Reported-by: syzbot+7534f060ebda6b8b51b3@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=7534f060ebda6b8b51b3
Tested-by: syzbot+7534f060ebda6b8b51b3@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: ebe9f6f19d80 ("acpi/nfit: Fix bus command validation")
Signed-off-by: Suraj Sonawane <surajsonawane0215@xxxxxxxxx>
---
V1: https://lore.kernel.org/lkml/20241111080429.9861-1-surajsonawane0215@xxxxxxxxx/
V2: Initialized `out_obj` to `NULL` in `acpi_nfit_ctl()` to prevent
potential uninitialized variable usage if condition is true.
V3: Changed the condition to if (!buf || buf_len < sizeof(*call_pkg))
and updated the Fixes tag to reference the correct commit.
V4: Removed the explicit cast to maintain the original code style.
drivers/acpi/nfit/core.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 5429ec9ef..84d8eef2a 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -454,8 +454,15 @@ int acpi_nfit_ctl(struct nvdimm_bus_descriptor *nd_desc, struct nvdimm *nvdimm,
if (cmd_rc)
*cmd_rc = -EINVAL;
- if (cmd == ND_CMD_CALL)
+ if (cmd == ND_CMD_CALL) {
+ if (!buf || buf_len < sizeof(*call_pkg)) {
+ rc = -EINVAL;
+ goto out;
This goto is wrong. This will result in ACPI_FREE() being called on an
undefined out_obj.
This should be:
return -EINVAL;
Thanks for catching that. You’re correct about the goto issue. I had
initialized out_obj to NULL in previous versions but missed it in this
patch. In v5, I’ve re-initialized out_obj to NULL, to avoid unintended
access. Here’s the updated patch link:
https://lore.kernel.org/lkml/20241116114027.19303-1-surajsonawane0215@xxxxxxxxx/
Ira
+ }
+
call_pkg = buf;
+ }
+
func = cmd_to_func(nfit_mem, cmd, call_pkg, &family);
if (func < 0)
return func;
--
2.34.1
Best Regards,
Suraj Sonawane
