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path: root/drivers/net/tap.c
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2017-10-28tap: reference to KVA of an unloaded module causes kernel panicGirish Moodalbail
The commit 9a393b5d5988 ("tap: tap as an independent module") created a separate tap module that implements tap functionality and exports interfaces that will be used by macvtap and ipvtap modules to create create respective tap devices. However, that patch introduced a regression wherein the modules macvtap and ipvtap can be removed (through modprobe -r) while there are applications using the respective /dev/tapX devices. These applications cause kernel to hold reference to /dev/tapX through 'struct cdev macvtap_cdev' and 'struct cdev ipvtap_dev' defined in macvtap and ipvtap modules respectively. So, when the application is later closed the kernel panics because we are referencing KVA that is present in the unloaded modules. ----------8<------- Example ----------8<---------- $ sudo ip li add name mv0 link enp7s0 type macvtap $ sudo ip li show mv0 |grep mv0| awk -e '{print $1 $2}' 14:mv0@enp7s0: $ cat /dev/tap14 & $ lsmod |egrep -i 'tap|vlan' macvtap 16384 0 macvlan 24576 1 macvtap tap 24576 3 macvtap $ sudo modprobe -r macvtap $ fg cat /dev/tap14 ^C <...system panics...> BUG: unable to handle kernel paging request at ffffffffa038c500 IP: cdev_put+0xf/0x30 ----------8<-----------------8<---------- The fix is to set cdev.owner to the module that creates the tap device (either macvtap or ipvtap). With this set, the operations (in fs/char_dev.c) on char device holds and releases the module through cdev_get() and cdev_put() and will not allow the module to unload prematurely. Fixes: 9a393b5d5988ea4e (tap: tap as an independent module) Signed-off-by: Girish Moodalbail <girish.moodalbail@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-26tap: double-free in error path in tap_open()Girish Moodalbail
Double free of skb_array in tap module is causing kernel panic. When tap_set_queue() fails we free skb_array right away by calling skb_array_cleanup(). However, later on skb_array_cleanup() is called again by tap_sock_destruct through sock_put(). This patch fixes that issue. Fixes: 362899b8725b35e3 (macvtap: switch to use skb array) Signed-off-by: Girish Moodalbail <girish.moodalbail@oracle.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-16tun/tap: use paren's with sizeofstephen hemminger
Although sizeof is an operator in C. The kernel coding style convention is to always use it like a function and add parenthesis. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-13tap: make struct tap_fops staticColin Ian King
The structure tap_fops is local to the source and does not need to be in global scope, so make it static. Cleans up sparse warning: symbol 'tap_fops' was not declared. Should it be static? Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-17tun/tap: Remove references to NETIF_F_UFO.David S. Miller
It is going away. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-11tap: convert a mutex to a spinlockWANG Cong
We are not allowed to block on the RCU reader side, so can't just hold the mutex as before. As a quick fix, convert it to a spinlock. Fixes: d9f1f61c0801 ("tap: Extending tap device create/destroy APIs") Reported-by: Christian Borntraeger <borntraeger@de.ibm.com> Tested-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Sainath Grandhi <sainath.grandhi@intel.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-18tap: support receiving skb from msg_controlJason Wang
This patch makes tap_recvmsg() can receive from skb from its caller through msg_control. Vhost_net will be the first user. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-18tap: export skb_arrayJason Wang
This patch exports skb_array through tap_get_skb_array(). Caller can then manipulate skb array directly. Signed-off-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-03-03sched/headers: Move task_struct::signal and task_struct::sighand types and ↵Ingo Molnar
accessors into <linux/sched/signal.h> task_struct::signal and task_struct::sighand are pointers, which would normally make it straightforward to not define those types in sched.h. That is not so, because the types are accompanied by a myriad of APIs (macros and inline functions) that dereference them. Split the types and the APIs out of sched.h and move them into a new header, <linux/sched/signal.h>. With this change sched.h does not know about 'struct signal' and 'struct sighand' anymore, trying to put accessors into sched.h as a test fails the following way: ./include/linux/sched.h: In function ‘test_signal_types’: ./include/linux/sched.h:2461:18: error: dereferencing pointer to incomplete type ‘struct signal_struct’ ^ This reduces the size and complexity of sched.h significantly. Update all headers and .c code that relied on getting the signal handling functionality from <linux/sched.h> to include <linux/sched/signal.h>. The list of affected files in the preparatory patch was partly generated by grepping for the APIs, and partly by doing coverage build testing, both all[yes|mod|def|no]config builds on 64-bit and 32-bit x86, and an array of cross-architecture builds. Nevertheless some (trivial) build breakage is still expected related to rare Kconfig combinations and in-flight patches to various kernel code, but most of it should be handled by this patch. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-02-11tap: tap as an independent moduleSainath Grandhi
This patch makes tap a separate module for other types of virtual interfaces, for example, ipvlan to use. Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-11tap: Extending tap device create/destroy APIsSainath Grandhi
Extending tap APIs get/free_minor and create/destroy_cdev to handle more than one type of virtual interface. Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-11tap: Abstract type of virtual interface from tap implementationSainath Grandhi
macvlan object is re-structured to hold tap related elements in a separate entity, tap_dev. Upon NETDEV_REGISTER device_event, tap_dev is registered with idr and fetched again on tap_open. Few of the tap functions are modified to accepted tap_dev as argument. tap_dev object includes callbacks to be used by underlying virtual interface to take care of tx and rx accounting. Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-11tap: Tap character device creation/destroy APISainath Grandhi
This patch provides tap device create/destroy APIs in tap.c. Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-11tap: Renaming tap related APIs, data structures, macrosSainath Grandhi
Renaming tap related APIs, data structures and macros in tap.c from macvtap_.* to tap_.* Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-02-11tap: Refactoring macvtap.cSainath Grandhi
macvtap module has code for tap/queue management and link management. This patch splits the code into macvtap_main.c for link management and tap.c for tap/queue management. Functionality in tap.c can be re-used for implementing tap on other virtual interfaces. Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>