On 13/11/24 10:21, Alison Schofield wrote:
On Tue, Nov 12, 2024 at 10:50:35AM +0530, 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 sized appropriately as a `struct nd_cmd_pkg`. This
could lead to out-of-bounds access and undefined behavior if the
buffer does not have sufficient space.
To address this issue, a check was added in `acpi_nfit_ctl()` to
ensure that `buf` is not `NULL` and `buf_len` is greater than or
equal to `sizeof(struct nd_cmd_pkg)` before casting `buf` to
`struct nd_cmd_pkg *`. This ensures safe access to the members of
`call_pkg`, including the `nd_reserved2` array.
This change preventing out-of-bounds reads.
Reported-by: syzbot+7534f060ebda6b8b51b3@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=7534f060ebda6b8b51b3
Tested-by: syzbot+7534f060ebda6b8b51b3@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 2d5404caa8c7 ("Linux 6.12-rc7")
Signed-off-by: Suraj Sonawane <surajsonawane0215@xxxxxxxxx>
Suraj,
The fixes tag needs to be where the issue originated, not
where you discovered it (which I'm guessing was using 6.12-rc7).
Thank you for your feedback.
Here's how I find the tag:
$ git blame drivers/acpi/nfit/core.c | grep call_pkg | grep buf
ebe9f6f19d80d drivers/acpi/nfit/core.c (Dan Williams 2019-02-07 14:56:50 -0800 458) call_pkg = buf;
$ git log -1 --pretty=fixes ebe9f6f19d80d
Thank you for this detailed explaination.
Fixes: ebe9f6f19d80 ("acpi/nfit: Fix bus command validation")
I think ^ should be your Fixes tag.
Yes, I ran the provided steps to verify the commit ID ebe9f6f19d80d and
verified it.
snip
I'll update the Fixes tag in the next version of the patch.
Additionally, I will re-test with syzbot and submit the revised patch
shortly.
Thank you for your time and feedback!
Best,
Suraj Sonawane
