Re: [PATCH 5.10.y] comedi: Fail COMEDI_INSNLIST ioctl if n_insns is too large

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

✅ All tests passed successfully. No issues detected.
No action required from the submitter.

The upstream commit SHA1 provided is correct: 08ae4b20f5e82101d77326ecab9089e110f224cc

Status in newer kernel trees:
6.15.y | Not found
6.12.y | Not found
6.6.y | Not found
6.1.y | Not found
5.15.y | Not found

Note: The patch differs from the upstream commit:
---
1:  08ae4b20f5e8 ! 1:  4a8bada4e031 comedi: Fail COMEDI_INSNLIST ioctl if n_insns is too large
    @@ Metadata
      ## Commit message ##
         comedi: Fail COMEDI_INSNLIST ioctl if n_insns is too large
     
    +    [ Upstream commit 08ae4b20f5e82101d77326ecab9089e110f224cc ]
    +
         The handling of the `COMEDI_INSNLIST` ioctl allocates a kernel buffer to
         hold the array of `struct comedi_insn`, getting the length from the
         `n_insns` member of the `struct comedi_insnlist` supplied by the user.
    @@ Commit message
         Link: https://lore.kernel.org/r/20250704120405.83028-1-abbotti@mev.co.uk
         Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
     
    - ## drivers/comedi/comedi_fops.c ##
    -@@ drivers/comedi/comedi_fops.c: static int do_insnlist_ioctl(struct comedi_device *dev,
    + ## drivers/staging/comedi/comedi_fops.c ##
    +@@ drivers/staging/comedi/comedi_fops.c: static int do_insnlist_ioctl(struct comedi_device *dev,
      	return i;
      }
      
    @@ drivers/comedi/comedi_fops.c: static int do_insnlist_ioctl(struct comedi_device
      /*
       * COMEDI_INSN ioctl
       * synchronous instruction
    -@@ drivers/comedi/comedi_fops.c: static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
    +@@ drivers/staging/comedi/comedi_fops.c: static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
      			rc = -EFAULT;
      			break;
      		}
    @@ drivers/comedi/comedi_fops.c: static long comedi_unlocked_ioctl(struct file *fil
      		insns = kcalloc(insnlist.n_insns, sizeof(*insns), GFP_KERNEL);
      		if (!insns) {
      			rc = -ENOMEM;
    -@@ drivers/comedi/comedi_fops.c: static int compat_insnlist(struct file *file, unsigned long arg)
    +@@ drivers/staging/comedi/comedi_fops.c: static int compat_insnlist(struct file *file, unsigned long arg)
      	if (copy_from_user(&insnlist32, compat_ptr(arg), sizeof(insnlist32)))
      		return -EFAULT;
      

---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| origin/linux-5.10.y       | Success     | Success    |