Bug 2420345 (CVE-2023-53826) - CVE-2023-53826 kernel: ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()
Summary: CVE-2023-53826 kernel: ubi: Fix UAF wear-leveling entry in eraseblk_count_seq...
Keywords:
Status: NEW
Alias: CVE-2023-53826
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: 2025-12-09 02:04 UTC by OSIDB Bzimport
Modified: 2025-12-12 09:46 UTC (History)
0 users

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2025-12-09 02:04:30 UTC
In the Linux kernel, the following vulnerability has been resolved:

ubi: Fix UAF wear-leveling entry in eraseblk_count_seq_show()

Wear-leveling entry could be freed in error path, which may be accessed
again in eraseblk_count_seq_show(), for example:

__erase_worker                eraseblk_count_seq_show
                                wl = ubi->lookuptbl[*block_number]
				if (wl)
  wl_entry_destroy
    ubi->lookuptbl[e->pnum] = NULL
    kmem_cache_free(ubi_wl_entry_slab, e)
		                   erase_count = wl->ec  // UAF!

Wear-leveling entry updating/accessing in ubi->lookuptbl should be
protected by ubi->wl_lock, fix it by adding ubi->wl_lock to serialize
wl entry accessing between wl_entry_destroy() and
eraseblk_count_seq_show().

Fetch a reproducer in [Link].


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