Bug 2334443 (CVE-2024-56624) - CVE-2024-56624 kernel: iommufd: Fix out_fput in iommufd_fault_alloc()
Summary: CVE-2024-56624 kernel: iommufd: Fix out_fput in iommufd_fault_alloc()
Keywords:
Status: NEW
Alias: CVE-2024-56624
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2024-12-27 15:02 UTC by OSIDB Bzimport
Modified: 2025-01-08 13:48 UTC (History)
4 users (show)

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


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Description OSIDB Bzimport 2024-12-27 15:02:23 UTC
In the Linux kernel, the following vulnerability has been resolved:

iommufd: Fix out_fput in iommufd_fault_alloc()

As fput() calls the file->f_op->release op, where fault obj and ictx are
getting released, there is no need to release these two after fput() one
more time, which would result in imbalanced refcounts:
  refcount_t: decrement hit 0; leaking memory.
  WARNING: CPU: 48 PID: 2369 at lib/refcount.c:31 refcount_warn_saturate+0x60/0x230
  Call trace:
   refcount_warn_saturate+0x60/0x230 (P)
   refcount_warn_saturate+0x60/0x230 (L)
   iommufd_fault_fops_release+0x9c/0xe0 [iommufd]
  ...
  VFS: Close: file count is 0 (f_op=iommufd_fops [iommufd])
  WARNING: CPU: 48 PID: 2369 at fs/open.c:1507 filp_flush+0x3c/0xf0
  Call trace:
   filp_flush+0x3c/0xf0 (P)
   filp_flush+0x3c/0xf0 (L)
   __arm64_sys_close+0x34/0x98
  ...
  imbalanced put on file reference count
  WARNING: CPU: 48 PID: 2369 at fs/file.c:74 __file_ref_put+0x100/0x138
  Call trace:
   __file_ref_put+0x100/0x138 (P)
   __file_ref_put+0x100/0x138 (L)
   __fput_sync+0x4c/0xd0

Drop those two lines to fix the warnings above.

Comment 1 Avinash Hanwate 2024-12-28 08:32:43 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024122711-CVE-2024-56624-35f7@gregkh/T


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