Bug 231514 - Potential null pointer deference in function ffec_alloc_mbufcl (sys/dev/ffec/if_ffec.c)
Summary: Potential null pointer deference in function ffec_alloc_mbufcl (sys/dev/ffec/...
Status: Closed FIXED
Alias: None
Product: Base System
Classification: Unclassified
Component: kern (show other bugs)
Version: CURRENT
Hardware: Any Any
: --- Affects Only Me
Assignee: Andrey V. Elsukov
URL:
Keywords: patch
Depends on:
Blocks:
 
Reported: 2018-09-20 13:28 UTC by Young
Modified: 2018-09-28 10:03 UTC (History)
1 user (show)

See Also:


Attachments
Patch_for_FFEC_NULL-POINTER-DEFERENCE (782 bytes, application/mbox)
2018-09-20 13:28 UTC, Young
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Description Young 2018-09-20 13:28:25 UTC
Created attachment 197278 [details]
Patch_for_FFEC_NULL-POINTER-DEFERENCE

There is a potential null pointer deference in function ffec_alloc_mbufcl (sys/dev/ffec/if_ffec.c).

 798 static struct mbuf *
 799 ffec_alloc_mbufcl(struct ffec_softc *sc)
 800 {
 801         struct mbuf *m;
 802 
 803         m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
 804         m->m_pkthdr.len = m->m_len = m->m_ext.ext_size;
 805 
 806         return (m);
 807 }

m_getcl(how,	type, flags)
Fetch an mbuf with a mbuf cluster attached to it.  If one of the allocations fails, the entire allocation fails. This routine is the preferred way of fetching both the mbuf and mbuf cluster together, as it avoids having to unlock/relock between allocations.
Returns NULL on failure.

if line 803 return NULL on failure, then there is a null pointer deference vulnerability.

The attachment is the proposal patch.
Comment 1 commit-hook freebsd_committer freebsd_triage 2018-09-21 13:44:20 UTC
A commit references this bug:

Author: ae
Date: Fri Sep 21 13:44:05 UTC 2018
New revision: 338857
URL: https://svnweb.freebsd.org/changeset/base/338857

Log:
  Fix possible NULL pointer dereference in ffec_alloc_mbufcl().

  PR:		231514
  Approved by:	re (kib)
  MFC after:	1 week

Changes:
  head/sys/dev/ffec/if_ffec.c
Comment 2 commit-hook freebsd_committer freebsd_triage 2018-09-28 10:03:47 UTC
A commit references this bug:

Author: ae
Date: Fri Sep 28 10:02:47 UTC 2018
New revision: 338992
URL: https://svnweb.freebsd.org/changeset/base/338992

Log:
  MFC r338857:
    Fix possible NULL pointer dereference in ffec_alloc_mbufcl().

    PR:		231514

Changes:
_U  stable/11/
  stable/11/sys/dev/ffec/if_ffec.c
Comment 3 Andrey V. Elsukov freebsd_committer freebsd_triage 2018-09-28 10:03:59 UTC
Fixed in head/ and stable/11. Thanks!