Scientific Linux Security Update : kernel on SL6.x i386/x86_64

This script is Copyright (C) 2017 Tenable Network Security, Inc.


Synopsis :

The remote Scientific Linux host is missing one or more security
updates.

Description :

Security Fix(es) :

- The NFSv2 and NFSv3 server implementations in the Linux
kernel through 4.10.13 lacked certain checks for the end
of a buffer. A remote attacker could trigger a
pointer-arithmetic error or possibly cause other
unspecified impacts using crafted requests related to
fs/nfsd/nfs3xdr.c and fs/nfsd/nfsxdr.c. (CVE-2017-7895,
Important)

Bug Fix(es) :

- If several file operations were started after a mounted
NFS share had got idle and its Transmission Control
Protocol (TCP) connection had therefore been terminated,
these operations could cause multiple TCP SYN packets
coming from the NFS client instead of one. With this
update, the reconnection logic has been fixed, and only
one TCP SYN packet is now sent in the described
situation.

- When the ixgbe driver was loaded for a
backplane-connected network card, a kernel panic could
occur, because the ops.setup_fc function pointer was
used before the initialization. With this update,
ops.setup_fc is initialized earlier. As a result, ixgbe
no longer panics on load.

- When setting an Access Control List (ACL) with 190 and
more Access Control Entries (ACEs) on a NFSv4 directory,
a kernel crash could previously occur. This update fixes
the nfs4_getfacl() function, and the kernel no longer
crashes under the described circumstances.

- When upgrading to kernel with the fix for stack guard
flaw, a crash could occur in Java Virtual Machine (JVM)
environments, which attempted to implement their own
stack guard page. With this update, the underlying
source code has been fixed to consider the PROT_NONE
mapping as a part of the stack, and the crash in JVM no
longer occurs under the described circumstances.

- When a program receives IPv6 packets using the raw
socket, the ioctl(FIONREAD) and ioctl(SIOCINQ) functions
can incorrectly return zero waiting bytes. This update
fixes the ip6_input_finish() function to check the raw
payload size properly. As a result, the ioctl() function
now returns bytes waiting in the raw socket correctly.

- Previously, listing a directory on a non-standard XFS
filesystem (with non-default multi-fsb directory blocks)
could lead to a soft lock up due to array index overrun
in the xfs_dir2_leaf_readbuf() function. This update
fixes xfs_dir2_leaf_readbuf(), and the soft lock up no
longer occurs under the described circumstances.

- Previously, aborts from the array after the Storage Area
Network (SAN) fabric back-pressure led to premature
reuse of still valid sequence with the same OX_ID.
Consequently, an error message and data corruption could
occur. This update fixes the libfc driver to isolate the
timed out OX_IDs, thus fixing this bug.

- Previously, a kernel panic occurred when the mcelog
daemon executed a huge page memory offline. This update
fixes the HugeTLB feature of the Linux kernel to check
for the Page Table Entry (PTE) NULL pointer in the
page_check_address() function. As a result, the kernel
panic no longer occurs under the described
circumstances.

See also :

http://www.nessus.org/u?e26d5e05

Solution :

Update the affected packages.

Risk factor :

Critical / CVSS Base Score : 10.0
(CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C)

Family: Scientific Linux Local Security Checks

Nessus Plugin ID: 101388 ()

Bugtraq ID:

CVE ID: CVE-2017-7895

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