linux.git/net/core/dev.c, branch v2.6.38 Linux kernel source tree net: don't allow CAP_NET_ADMIN to load non-netdev kernel modules 2011-03-09T23:25:19+00:00 Vasiliy Kulikov segoon@openwall.com 2011-03-01T21:33:13+00:00 8909c9ad8ff03611c9c96c9a92656213e4bb495b Since a8f80e8ff94ecba629542d9b4b5f5a8ee3eb565c any process with CAP_NET_ADMIN may load any module from /lib/modules/. This doesn't mean that CAP_NET_ADMIN is a superset of CAP_SYS_MODULE as modules are limited to /lib/modules/**. However, CAP_NET_ADMIN capability shouldn't allow anybody load any module not related to networking. This patch restricts an ability of autoloading modules to netdev modules with explicit aliases. This fixes CVE-2011-1019. Arnd Bergmann suggested to leave untouched the old pre-v2.6.32 behavior of loading netdev modules by name (without any prefix) for processes with CAP_SYS_MODULE to maintain the compatibility with network scripts that use autoloading netdev modules by aliases like "eth0", "wlan0". Currently there are only three users of the feature in the upstream kernel: ipip, ip_gre and sit. root@albatros:~# capsh --drop=$(seq -s, 0 11),$(seq -s, 13 34) -- root@albatros:~# grep Cap /proc/$$/status CapInh: 0000000000000000 CapPrm: fffffff800001000 CapEff: fffffff800001000 CapBnd: fffffff800001000 root@albatros:~# modprobe xfs FATAL: Error inserting xfs (/lib/modules/2.6.38-rc6-00001-g2bf4ca3/kernel/fs/xfs/xfs.ko): Operation not permitted root@albatros:~# lsmod | grep xfs root@albatros:~# ifconfig xfs xfs: error fetching interface information: Device not found root@albatros:~# lsmod | grep xfs root@albatros:~# lsmod | grep sit root@albatros:~# ifconfig sit sit: error fetching interface information: Device not found root@albatros:~# lsmod | grep sit root@albatros:~# ifconfig sit0 sit0 Link encap:IPv6-in-IPv4 NOARP MTU:1480 Metric:1 root@albatros:~# lsmod | grep sit sit 10457 0 tunnel4 2957 1 sit For CAP_SYS_MODULE module loading is still relaxed: root@albatros:~# grep Cap /proc/$$/status CapInh: 0000000000000000 CapPrm: ffffffffffffffff CapEff: ffffffffffffffff CapBnd: ffffffffffffffff root@albatros:~# ifconfig xfs xfs: error fetching interface information: Device not found root@albatros:~# lsmod | grep xfs xfs 745319 0 Reference: https://lkml.org/lkml/2011/2/24/203 Signed-off-by: Vasiliy Kulikov <segoon@openwall.com> Signed-off-by: Michael Tokarev <mjt@tls.msk.ru> Acked-by: David S. Miller <davem@davemloft.net> Acked-by: Kees Cook <kees.cook@canonical.com> Signed-off-by: James Morris <jmorris@namei.org> 
Since a8f80e8ff94ecba629542d9b4b5f5a8ee3eb565c any process with
CAP_NET_ADMIN may load any module from /lib/modules/.  This doesn't mean
that CAP_NET_ADMIN is a superset of CAP_SYS_MODULE as modules are
limited to /lib/modules/**.  However, CAP_NET_ADMIN capability shouldn't
allow anybody load any module not related to networking.

This patch restricts an ability of autoloading modules to netdev modules
with explicit aliases.  This fixes CVE-2011-1019.

Arnd Bergmann suggested to leave untouched the old pre-v2.6.32 behavior
of loading netdev modules by name (without any prefix) for processes
with CAP_SYS_MODULE to maintain the compatibility with network scripts
that use autoloading netdev modules by aliases like "eth0", "wlan0".

Currently there are only three users of the feature in the upstream
kernel: ipip, ip_gre and sit.

    root@albatros:~# capsh --drop=$(seq -s, 0 11),$(seq -s, 13 34) --
    root@albatros:~# grep Cap /proc/$$/status
    CapInh:	0000000000000000
    CapPrm:	fffffff800001000
    CapEff:	fffffff800001000
    CapBnd:	fffffff800001000
    root@albatros:~# modprobe xfs
    FATAL: Error inserting xfs
    (/lib/modules/2.6.38-rc6-00001-g2bf4ca3/kernel/fs/xfs/xfs.ko): Operation not permitted
    root@albatros:~# lsmod | grep xfs
    root@albatros:~# ifconfig xfs
    xfs: error fetching interface information: Device not found
    root@albatros:~# lsmod | grep xfs
    root@albatros:~# lsmod | grep sit
    root@albatros:~# ifconfig sit
    sit: error fetching interface information: Device not found
    root@albatros:~# lsmod | grep sit
    root@albatros:~# ifconfig sit0
    sit0      Link encap:IPv6-in-IPv4
	      NOARP  MTU:1480  Metric:1

    root@albatros:~# lsmod | grep sit
    sit                    10457  0
    tunnel4                 2957  1 sit

For CAP_SYS_MODULE module loading is still relaxed:

    root@albatros:~# grep Cap /proc/$$/status
    CapInh:	0000000000000000
    CapPrm:	ffffffffffffffff
    CapEff:	ffffffffffffffff
    CapBnd:	ffffffffffffffff
    root@albatros:~# ifconfig xfs
    xfs: error fetching interface information: Device not found
    root@albatros:~# lsmod | grep xfs
    xfs                   745319  0

Reference: https://lkml.org/lkml/2011/2/24/203

Signed-off-by: Vasiliy Kulikov <segoon@openwall.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
net: deinit automatic LIST_HEAD 2011-02-18T19:49:36+00:00 Eric Dumazet eric.dumazet@gmail.com 2011-02-17T22:59:19+00:00 ceaaec98ad99859ac90ac6863ad0a6cd075d8e0e commit 9b5e383c11b08784 (net: Introduce unregister_netdevice_many()) left an active LIST_HEAD() in rollback_registered(), with possible memory corruption. Even if device is freed without touching its unreg_list (and therefore touching the previous memory location holding LISTE_HEAD(single), better close the bug for good, since its really subtle. (Same fix for default_device_exit_batch() for completeness) Reported-by: Michal Hocko <mhocko@suse.cz> Tested-by: Michal Hocko <mhocko@suse.cz> Reported-by: Eric W. Biderman <ebiderman@xmission.com> Tested-by: Eric W. Biderman <ebiderman@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Ingo Molnar <mingo@elte.hu> CC: Octavian Purdila <opurdila@ixiacom.com> CC: stable <stable@kernel.org> [.33+] Signed-off-by: David S. Miller <davem@davemloft.net> 
commit 9b5e383c11b08784 (net: Introduce
unregister_netdevice_many()) left an active LIST_HEAD() in
rollback_registered(), with possible memory corruption.

Even if device is freed without touching its unreg_list (and therefore
touching the previous memory location holding LISTE_HEAD(single), better
close the bug for good, since its really subtle.

(Same fix for default_device_exit_batch() for completeness)

Reported-by: Michal Hocko <mhocko@suse.cz>
Tested-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Eric W. Biderman <ebiderman@xmission.com>
Tested-by: Eric W. Biderman <ebiderman@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Octavian Purdila <opurdila@ixiacom.com>
CC: stable <stable@kernel.org> [.33+]
Signed-off-by: David S. Miller <davem@davemloft.net>
net: dont leave active on stack LIST_HEAD 2011-02-18T19:49:35+00:00 Linus Torvalds torvalds@linux-foundation.org 2011-02-17T22:54:38+00:00 f87e6f47933e3ebeced9bb12615e830a72cedce4 Eric W. Biderman and Michal Hocko reported various memory corruptions that we suspected to be related to a LIST head located on stack, that was manipulated after thread left function frame (and eventually exited, so its stack was freed and reused). Eric Dumazet suggested the problem was probably coming from commit 443457242beb (net: factorize sync-rcu call in unregister_netdevice_many) This patch fixes __dev_close() and dev_close() to properly deinit their respective LIST_HEAD(single) before exiting. References: https://lkml.org/lkml/2011/2/16/304 References: https://lkml.org/lkml/2011/2/14/223 Reported-by: Michal Hocko <mhocko@suse.cz> Tested-by: Michal Hocko <mhocko@suse.cz> Reported-by: Eric W. Biderman <ebiderman@xmission.com> Tested-by: Eric W. Biderman <ebiderman@xmission.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> CC: Ingo Molnar <mingo@elte.hu> CC: Octavian Purdila <opurdila@ixiacom.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Eric W. Biderman and Michal Hocko reported various memory corruptions
that we suspected to be related to a LIST head located on stack, that
was manipulated after thread left function frame (and eventually exited,
so its stack was freed and reused).

Eric Dumazet suggested the problem was probably coming from commit
443457242beb (net: factorize
sync-rcu call in unregister_netdevice_many)

This patch fixes __dev_close() and dev_close() to properly deinit their
respective LIST_HEAD(single) before exiting.

References: https://lkml.org/lkml/2011/2/16/304
References: https://lkml.org/lkml/2011/2/14/223

Reported-by: Michal Hocko <mhocko@suse.cz>
Tested-by: Michal Hocko <mhocko@suse.cz>
Reported-by: Eric W. Biderman <ebiderman@xmission.com>
Tested-by: Eric W. Biderman <ebiderman@xmission.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
CC: Ingo Molnar <mingo@elte.hu>
CC: Octavian Purdila <opurdila@ixiacom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Fix lockdep regression caused by initializing netdev queues too early. 2011-02-08T23:02:50+00:00 David S. Miller davem@davemloft.net 2011-02-08T23:02:50+00:00 8d3bdbd55a7e2a3f2c148a4830aa26dd682b21c4 In commit aa9421041128abb4d269ee1dc502ff65fb3b7d69 ("net: init ingress queue") we moved the allocation and lock initialization of the queues into alloc_netdev_mq() since register_netdevice() is way too late. The problem is that dev->type is not setup until the setup() callback is invoked by alloc_netdev_mq(), and the dev->type is what determines the lockdep class to use for the locks in the queues. Fix this by doing the queue allocation after the setup() callback runs. This is safe because the setup() callback is not allowed to make any state changes that need to be undone on error (memory allocations, etc.). It may, however, make state changes that are undone by free_netdev() (such as netif_napi_add(), which is done by the ipoib driver's setup routine). The previous code also leaked a reference to the &init_net namespace object on RX/TX queue allocation failures. Signed-off-by: David S. Miller <davem@davemloft.net> 
In commit aa9421041128abb4d269ee1dc502ff65fb3b7d69 ("net: init ingress
queue") we moved the allocation and lock initialization of the queues
into alloc_netdev_mq() since register_netdevice() is way too late.

The problem is that dev->type is not setup until the setup()
callback is invoked by alloc_netdev_mq(), and the dev->type is
what determines the lockdep class to use for the locks in the
queues.

Fix this by doing the queue allocation after the setup() callback
runs.

This is safe because the setup() callback is not allowed to make any
state changes that need to be undone on error (memory allocations,
etc.).  It may, however, make state changes that are undone by
free_netdev() (such as netif_napi_add(), which is done by the
ipoib driver's setup routine).

The previous code also leaked a reference to the &init_net namespace
object on RX/TX queue allocation failures.

Signed-off-by: David S. Miller <davem@davemloft.net>
gro: reset skb_iif on reuse 2011-02-02T22:53:25+00:00 Andy Gospodarek andy@greyhouse.net 2011-02-02T22:53:25+00:00 6d152e23ad1a7a5b40fef1f42e017d66e6115159 Like Herbert's change from a few days ago: 66c46d741e2e60f0e8b625b80edb0ab820c46d7a gro: Reset dev pointer on reuse this may not be necessary at this point, but we should still clean up the skb->skb_iif. If not we may end up with an invalid valid for skb->skb_iif when the skb is reused and the check is done in __netif_receive_skb. Signed-off-by: Andy Gospodarek <andy@greyhouse.net> Signed-off-by: David S. Miller <davem@davemloft.net> 
Like Herbert's change from a few days ago:

66c46d741e2e60f0e8b625b80edb0ab820c46d7a gro: Reset dev pointer on reuse

this may not be necessary at this point, but we should still clean up
the skb->skb_iif.  If not we may end up with an invalid valid for
skb->skb_iif when the skb is reused and the check is done in
__netif_receive_skb.

Signed-off-by: Andy Gospodarek <andy@greyhouse.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
net: Check rps_flow_table when RPS map length is 1 2011-02-01T00:23:42+00:00 Tom Herbert therbert@google.com 2011-02-01T00:23:42+00:00 8587523640441a9ff2564ebc6efeb39497ad6709 In get_rps_cpu, add check that the rps_flow_table for the device is NULL when trying to take fast path when RPS map length is one. Without this, RFS is effectively disabled if map length is one which is not correct. Signed-off-by: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In get_rps_cpu, add check that the rps_flow_table for the device is
NULL when trying to take fast path when RPS map length is one.
Without this, RFS is effectively disabled if map length is one which
is not correct.

Signed-off-by: Tom Herbert <therbert@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
gro: Reset dev pointer on reuse 2011-01-30T06:36:24+00:00 Herbert Xu herbert@gondor.apana.org.au 2011-01-30T04:44:54+00:00 66c46d741e2e60f0e8b625b80edb0ab820c46d7a On older kernels the VLAN code may zero skb->dev before dropping it and causing it to be reused by GRO. Unfortunately we didn't reset skb->dev in that case which causes the next GRO user to get a bogus skb->dev pointer. This particular problem no longer happens with the current upstream kernel due to changes in VLAN processing. However, for correctness we should still reset the skb->dev pointer in the GRO reuse function in case a future user does the same thing. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net> 
On older kernels the VLAN code may zero skb->dev before dropping
it and causing it to be reused by GRO.

Unfortunately we didn't reset skb->dev in that case which causes
the next GRO user to get a bogus skb->dev pointer.

This particular problem no longer happens with the current upstream
kernel due to changes in VLAN processing.

However, for correctness we should still reset the skb->dev pointer
in the GRO reuse function in case a future user does the same thing.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/torvalds/linux-2.6 2011-01-24T21:17:06+00:00 David S. Miller davem@davemloft.net 2011-01-24T21:17:06+00:00 e92427b289d252cfbd4cb5282d92f4ce1a5bb1fb 






net: arp_ioctl() must hold RTNL
2011-01-24T21:16:16+00:00

Eric Dumazet
eric.dumazet@gmail.com

2011-01-24T21:16:16+00:00

c506653d35249bb4738bb139c24362e1ae724bc1

Commit 941666c2e3e0 "net: RCU conversion of dev_getbyhwaddr() and
arp_ioctl()" introduced a regression, reported by Jamie Heilman.
"arp -Ds 192.168.2.41 eth0 pub" triggered the ASSERT_RTNL() assert
in pneigh_lookup()

Removing RTNL requirement from arp_ioctl() was a mistake, just revert
that part.

Reported-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>





Commit 941666c2e3e0 "net: RCU conversion of dev_getbyhwaddr() and
arp_ioctl()" introduced a regression, reported by Jamie Heilman.
"arp -Ds 192.168.2.41 eth0 pub" triggered the ASSERT_RTNL() assert
in pneigh_lookup()

Removing RTNL requirement from arp_ioctl() was a mistake, just revert
that part.

Reported-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>







Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
2011-01-20T04:25:45+00:00

Linus Torvalds
torvalds@linux-foundation.org

2011-01-20T04:25:45+00:00

1268afe676ee9431a229fc68a2efb0dad4d5852f

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (41 commits)
  sctp: user perfect name for Delayed SACK Timer option
  net: fix can_checksum_protocol() arguments swap
  Revert "netlink: test for all flags of the NLM_F_DUMP composite"
  gianfar: Fix misleading indentation in startup_gfar()
  net/irda/sh_irda: return to RX mode when TX error
  net offloading: Do not mask out NETIF_F_HW_VLAN_TX for vlan.
  USB CDC NCM: tx_fixup() race condition fix
  ns83820: Avoid bad pointer deref in ns83820_init_one().
  ipv6: Silence privacy extensions initialization
  bnx2x: Update bnx2x version to 1.62.00-4
  bnx2x: Fix AER setting for BCM57712
  bnx2x: Fix BCM84823 LED behavior
  bnx2x: Mark full duplex on some external PHYs
  bnx2x: Fix BCM8073/BCM8727 microcode loading
  bnx2x: LED fix for BCM8727 over BCM57712
  bnx2x: Common init will be executed only once after POR
  bnx2x: Swap BCM8073 PHY polarity if required
  iwlwifi: fix valid chain reading from EEPROM
  ath5k: fix locking in tx_complete_poll_work
  ath9k_hw: do PA offset calibration only on longcal interval
  ...





* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: (41 commits)
  sctp: user perfect name for Delayed SACK Timer option
  net: fix can_checksum_protocol() arguments swap
  Revert "netlink: test for all flags of the NLM_F_DUMP composite"
  gianfar: Fix misleading indentation in startup_gfar()
  net/irda/sh_irda: return to RX mode when TX error
  net offloading: Do not mask out NETIF_F_HW_VLAN_TX for vlan.
  USB CDC NCM: tx_fixup() race condition fix
  ns83820: Avoid bad pointer deref in ns83820_init_one().
  ipv6: Silence privacy extensions initialization
  bnx2x: Update bnx2x version to 1.62.00-4
  bnx2x: Fix AER setting for BCM57712
  bnx2x: Fix BCM84823 LED behavior
  bnx2x: Mark full duplex on some external PHYs
  bnx2x: Fix BCM8073/BCM8727 microcode loading
  bnx2x: LED fix for BCM8727 over BCM57712
  bnx2x: Common init will be executed only once after POR
  bnx2x: Swap BCM8073 PHY polarity if required
  iwlwifi: fix valid chain reading from EEPROM
  ath5k: fix locking in tx_complete_poll_work
  ath9k_hw: do PA offset calibration only on longcal interval
  ...