5.5

CVE-2023-53584

In the Linux kernel, the following vulnerability has been resolved:

ubifs: ubifs_releasepage: Remove ubifs_assert(0) to valid this process

There are two states for ubifs writing pages:
1. Dirty, Private
2. Not Dirty, Not Private

The normal process cannot go to ubifs_releasepage() which means there
exists pages being private but not dirty. Reproducer[1] shows that it
could occur (which maybe related to [2]) with following process:

     PA                     PB                    PC
lock(page)[PA]
ubifs_write_end
  attach_page_private         // set Private
  __set_page_dirty_nobuffers  // set Dirty
unlock(page)

write_cache_pages[PA]
  lock(page)
  clear_page_dirty_for_io(page)	// clear Dirty
  ubifs_writepage

                        do_truncation[PB]
			  truncate_setsize
			    i_size_write(inode, newsize) // newsize = 0

    i_size = i_size_read(inode)	// i_size = 0
    end_index = i_size >> PAGE_SHIFT
    if (page->index > end_index)
      goto out // jump
out:
unlock(page)   // Private, Not Dirty

						generic_fadvise[PC]
						  lock(page)
						  invalidate_inode_page
						    try_to_release_page
						      ubifs_releasepage
						        ubifs_assert(c, 0)
		                                        // bad assertion!
						  unlock(page)
			  truncate_pagecache[PB]

Then we may get following assertion failed:
  UBIFS error (ubi0:0 pid 1683): ubifs_assert_failed [ubifs]:
  UBIFS assert failed: 0, in fs/ubifs/file.c:1513
  UBIFS warning (ubi0:0 pid 1683): ubifs_ro_mode [ubifs]:
  switched to read-only mode, error -22
  CPU: 2 PID: 1683 Comm: aa Not tainted 5.16.0-rc5-00184-g0bca5994cacc-dirty #308
  Call Trace:
    dump_stack+0x13/0x1b
    ubifs_ro_mode+0x54/0x60 [ubifs]
    ubifs_assert_failed+0x4b/0x80 [ubifs]
    ubifs_releasepage+0x67/0x1d0 [ubifs]
    try_to_release_page+0x57/0xe0
    invalidate_inode_page+0xfb/0x130
    __invalidate_mapping_pages+0xb9/0x280
    invalidate_mapping_pagevec+0x12/0x20
    generic_fadvise+0x303/0x3c0
    ksys_fadvise64_64+0x4c/0xb0

[1] https://bugzilla.kernel.org/show_bug.cgi?id=215373
[2] https://linux-mtd.infradead.narkive.com/NQoBeT1u/patch-rfc-ubifs-fix-assert-failed-in-ubifs-set-page-dirty
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Daten sind bereitgestellt durch National Vulnerability Database (NVD)
LinuxLinux Kernel Version >= 2.6.27 < 6.1.18
LinuxLinux Kernel Version >= 6.2 < 6.2.5
Zu dieser CVE wurde keine CISA KEV oder CERT.AT-Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.01% 0.005
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 5.5 1.8 3.6
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-617 Reachable Assertion

The product contains an assert() or similar statement that can be triggered by an attacker, which leads to an application exit or other behavior that is more severe than necessary.