On 11/18/24 21:56, 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.
V5: Re-Initialized `out_obj` to NULL. To prevent
potential uninitialized variable usage if condition is true.
V6: Remove the goto out condition from the error handling and directly
returned -EINVAL in the check for buf and buf_len
drivers/acpi/nfit/core.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/acpi/nfit/core.c b/drivers/acpi/nfit/core.c
index 5429ec9ef..a5d47819b 100644
--- a/drivers/acpi/nfit/core.c
+++ b/drivers/acpi/nfit/core.c
@@ -454,8 +454,13 @@ 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))
+ return -EINVAL;
+
call_pkg = buf;
+ }
+
func = cmd_to_func(nfit_mem, cmd, call_pkg, &family);
if (func < 0)
return func;
Hello!
I wanted to follow up on the patch I submitted. I have incorporated all
the suggested changes up to v6. I was wondering if you had a chance to
review it and if there are any comments or feedback.
Here are the links to the discussion for all versions:
https://lore.kernel.org/lkml/?q=acpi%3A+nfit%3A+vmalloc-out-of-bounds+Read+in+acpi_nfit_ctl
Thank you for your time and consideration. I look forward to your response.
Best regards,
Suraj Sonawane
