linux-stable.git/net/ipv6/ip6mr.c, branch linux-4.4.y Linux kernel stable tree ipv6: do not abuse GFP_ATOMIC in inet6_netconf_notify_devconf() 2020-05-10T08:26:16+00:00 Eric Dumazet edumazet@google.com 2016-07-08T03:46:04+00:00 20cb4e9180b8bd1ac35ca3c0c1ed544387a96a8f commit 927265bc6cd6374c9bafc43408ece4e92311b149 upstream. All inet6_netconf_notify_devconf() callers are in process context, so we can use GFP_KERNEL allocations if we take care of not holding a rwlock while not needed in ip6mr (we hold RTNL there) Fixes: d67b8c616b48 ("netconf: advertise mc_forwarding status") Fixes: f3a1bfb11ccb ("rtnl/ipv6: use netconf msg to advertise forwarding status") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 927265bc6cd6374c9bafc43408ece4e92311b149 upstream.

All inet6_netconf_notify_devconf() callers are in process context,
so we can use GFP_KERNEL allocations if we take care of not holding
a rwlock while not needed in ip6mr (we hold RTNL there)

Fixes: d67b8c616b48 ("netconf: advertise mc_forwarding status")
Fixes: f3a1bfb11ccb ("rtnl/ipv6: use netconf msg to advertise forwarding status")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipv6: check sk sk_type and protocol early in ip_mroute_set/getsockopt 2019-08-04T07:35:01+00:00 Xin Long lucien.xin@gmail.com 2017-02-24T08:29:06+00:00 ee2f25641633ffb03fb88e4fa8a6424d24d3f295 [ Upstream commit 99253eb750fda6a644d5188fb26c43bad8d5a745 ] Commit 5e1859fbcc3c ("ipv4: ipmr: various fixes and cleanups") fixed the issue for ipv4 ipmr: ip_mroute_setsockopt() & ip_mroute_getsockopt() should not access/set raw_sk(sk)->ipmr_table before making sure the socket is a raw socket, and protocol is IGMP The same fix should be done for ipv6 ipmr as well. This patch can fix the panic caused by overwriting the same offset as ipmr_table as in raw_sk(sk) when accessing other type's socket by ip_mroute_setsockopt(). Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 99253eb750fda6a644d5188fb26c43bad8d5a745 ]

Commit 5e1859fbcc3c ("ipv4: ipmr: various fixes and cleanups") fixed
the issue for ipv4 ipmr:

  ip_mroute_setsockopt() & ip_mroute_getsockopt() should not
  access/set raw_sk(sk)->ipmr_table before making sure the socket
  is a raw socket, and protocol is IGMP

The same fix should be done for ipv6 ipmr as well.

This patch can fix the panic caused by overwriting the same offset
as ipmr_table as in raw_sk(sk) when accessing other type's socket
by ip_mroute_setsockopt().

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip6mr: Do not call __IP6_INC_STATS() from preemptible context 2019-03-23T07:44:24+00:00 Ido Schimmel idosch@mellanox.com 2019-03-03T07:34:57+00:00 c9b1f85066723740f3e23fba7a974a42ca545507 [ Upstream commit 87c11f1ddbbad38ad8bad47af133a8208985fbdf ] Similar to commit 44f49dd8b5a6 ("ipmr: fix possible race resulting from improper usage of IP_INC_STATS_BH() in preemptible context."), we cannot assume preemption is disabled when incrementing the counter and accessing a per-CPU variable. Preemption can be enabled when we add a route in process context that corresponds to packets stored in the unresolved queue, which are then forwarded using this route [1]. Fix this by using IP6_INC_STATS() which takes care of disabling preemption on architectures where it is needed. [1] [ 157.451447] BUG: using __this_cpu_add() in preemptible [00000000] code: smcrouted/2314 [ 157.460409] caller is ip6mr_forward2+0x73e/0x10e0 [ 157.460434] CPU: 3 PID: 2314 Comm: smcrouted Not tainted 5.0.0-rc7-custom-03635-g22f2712113f1 #1336 [ 157.460449] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016 [ 157.460461] Call Trace: [ 157.460486] dump_stack+0xf9/0x1be [ 157.460553] check_preemption_disabled+0x1d6/0x200 [ 157.460576] ip6mr_forward2+0x73e/0x10e0 [ 157.460705] ip6_mr_forward+0x9a0/0x1510 [ 157.460771] ip6mr_mfc_add+0x16b3/0x1e00 [ 157.461155] ip6_mroute_setsockopt+0x3cb/0x13c0 [ 157.461384] do_ipv6_setsockopt.isra.8+0x348/0x4060 [ 157.462013] ipv6_setsockopt+0x90/0x110 [ 157.462036] rawv6_setsockopt+0x4a/0x120 [ 157.462058] __sys_setsockopt+0x16b/0x340 [ 157.462198] __x64_sys_setsockopt+0xbf/0x160 [ 157.462220] do_syscall_64+0x14d/0x610 [ 157.462349] entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: 0912ea38de61 ("[IPV6] MROUTE: Add stats in multicast routing module method ip6_mr_forward().") Signed-off-by: Ido Schimmel <idosch@mellanox.com> Reported-by: Amit Cohen <amitc@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 87c11f1ddbbad38ad8bad47af133a8208985fbdf ]

Similar to commit 44f49dd8b5a6 ("ipmr: fix possible race resulting from
improper usage of IP_INC_STATS_BH() in preemptible context."), we cannot
assume preemption is disabled when incrementing the counter and
accessing a per-CPU variable.

Preemption can be enabled when we add a route in process context that
corresponds to packets stored in the unresolved queue, which are then
forwarded using this route [1].

Fix this by using IP6_INC_STATS() which takes care of disabling
preemption on architectures where it is needed.

[1]
[  157.451447] BUG: using __this_cpu_add() in preemptible [00000000] code: smcrouted/2314
[  157.460409] caller is ip6mr_forward2+0x73e/0x10e0
[  157.460434] CPU: 3 PID: 2314 Comm: smcrouted Not tainted 5.0.0-rc7-custom-03635-g22f2712113f1 #1336
[  157.460449] Hardware name: Mellanox Technologies Ltd. MSN2100-CB2FO/SA001017, BIOS 5.6.5 06/07/2016
[  157.460461] Call Trace:
[  157.460486]  dump_stack+0xf9/0x1be
[  157.460553]  check_preemption_disabled+0x1d6/0x200
[  157.460576]  ip6mr_forward2+0x73e/0x10e0
[  157.460705]  ip6_mr_forward+0x9a0/0x1510
[  157.460771]  ip6mr_mfc_add+0x16b3/0x1e00
[  157.461155]  ip6_mroute_setsockopt+0x3cb/0x13c0
[  157.461384]  do_ipv6_setsockopt.isra.8+0x348/0x4060
[  157.462013]  ipv6_setsockopt+0x90/0x110
[  157.462036]  rawv6_setsockopt+0x4a/0x120
[  157.462058]  __sys_setsockopt+0x16b/0x340
[  157.462198]  __x64_sys_setsockopt+0xbf/0x160
[  157.462220]  do_syscall_64+0x14d/0x610
[  157.462349]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 0912ea38de61 ("[IPV6] MROUTE: Add stats in multicast routing module method ip6_mr_forward().")
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Reported-by: Amit Cohen <amitc@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip6mr: Fix potential Spectre v1 vulnerability 2019-01-13T09:05:27+00:00 Gustavo A. R. Silva gustavo@embeddedor.com 2018-12-11T20:10:08+00:00 6dc50507697ce02fc8118e794b9ffdb20e6ed4ea [ Upstream commit 69d2c86766da2ded2b70281f1bf242cb0d58a778 ] vr.mifi is indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: net/ipv6/ip6mr.c:1845 ip6mr_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) net/ipv6/ip6mr.c:1919 ip6mr_compat_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap) Fix this by sanitizing vr.mifi before using it to index mrt->vif_table' Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 69d2c86766da2ded2b70281f1bf242cb0d58a778 ]

vr.mifi is indirectly controlled by user-space, hence leading to
a potential exploitation of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

net/ipv6/ip6mr.c:1845 ip6mr_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap)
net/ipv6/ip6mr.c:1919 ip6mr_compat_ioctl() warn: potential spectre issue 'mrt->vif_table' [r] (local cap)

Fix this by sanitizing vr.mifi before using it to index mrt->vif_table'

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip6mr: only set ip6mr_table from setsockopt when ip6mr_new_table succeeds 2018-06-13T14:15:28+00:00 Sabrina Dubroca sd@queasysnail.net 2018-06-05T13:01:59+00:00 53075e7abd39ef17e6b94c23451948641e935adb [ Upstream commit 848235edb5c93ed086700584c8ff64f6d7fc778d ] Currently, raw6_sk(sk)->ip6mr_table is set unconditionally during ip6_mroute_setsockopt(MRT6_TABLE). A subsequent attempt at the same setsockopt will fail with -ENOENT, since we haven't actually created that table. A similar fix for ipv4 was included in commit 5e1859fbcc3c ("ipv4: ipmr: various fixes and cleanups"). Fixes: d1db275dd3f6 ("ipv6: ip6mr: support multiple tables") Signed-off-by: Sabrina Dubroca <sd@queasysnail.net> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 848235edb5c93ed086700584c8ff64f6d7fc778d ]

Currently, raw6_sk(sk)->ip6mr_table is set unconditionally during
ip6_mroute_setsockopt(MRT6_TABLE). A subsequent attempt at the same
setsockopt will fail with -ENOENT, since we haven't actually created
that table.

A similar fix for ipv4 was included in commit 5e1859fbcc3c ("ipv4: ipmr:
various fixes and cleanups").

Fixes: d1db275dd3f6 ("ipv6: ip6mr: support multiple tables")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip6mr: fix stale iterator 2018-02-16T19:09:37+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2018-01-31T14:29:30+00:00 fff4f776df44afa3fd6ce043ca82c8b317294ad1 [ Upstream commit 4adfa79fc254efb7b0eb3cd58f62c2c3f805f1ba ] When we dump the ip6mr mfc entries via proc, we initialize an iterator with the table to dump but we don't clear the cache pointer which might be initialized from a prior read on the same descriptor that ended. This can result in lock imbalance (an unnecessary unlock) leading to other crashes and hangs. Clear the cache pointer like ipmr does to fix the issue. Thanks for the reliable reproducer. Here's syzbot's trace: WARNING: bad unlock balance detected! 4.15.0-rc3+ #128 Not tainted syzkaller971460/3195 is trying to release lock (mrt_lock) at: [<000000006898068d>] ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553 but there are no more locks to release! other info that might help us debug this: 1 lock held by syzkaller971460/3195: #0: (&p->lock){+.+.}, at: [<00000000744a6565>] seq_read+0xd5/0x13d0 fs/seq_file.c:165 stack backtrace: CPU: 1 PID: 3195 Comm: syzkaller971460 Not tainted 4.15.0-rc3+ #128 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 print_unlock_imbalance_bug+0x12f/0x140 kernel/locking/lockdep.c:3561 __lock_release kernel/locking/lockdep.c:3775 [inline] lock_release+0x5f9/0xda0 kernel/locking/lockdep.c:4023 __raw_read_unlock include/linux/rwlock_api_smp.h:225 [inline] _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255 ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553 traverse+0x3bc/0xa00 fs/seq_file.c:135 seq_read+0x96a/0x13d0 fs/seq_file.c:189 proc_reg_read+0xef/0x170 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:673 [inline] do_iter_read+0x3db/0x5b0 fs/read_write.c:897 compat_readv+0x1bf/0x270 fs/read_write.c:1140 do_compat_preadv64+0xdc/0x100 fs/read_write.c:1189 C_SYSC_preadv fs/read_write.c:1209 [inline] compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1203 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125 RIP: 0023:0xf7f73c79 RSP: 002b:00000000e574a15c EFLAGS: 00000292 ORIG_RAX: 000000000000014d RAX: ffffffffffffffda RBX: 000000000000000f RCX: 0000000020a3afb0 RDX: 0000000000000001 RSI: 0000000000000067 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 BUG: sleeping function called from invalid context at lib/usercopy.c:25 in_atomic(): 1, irqs_disabled(): 0, pid: 3195, name: syzkaller971460 INFO: lockdep is turned off. CPU: 1 PID: 3195 Comm: syzkaller971460 Not tainted 4.15.0-rc3+ #128 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x257 lib/dump_stack.c:53 ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6060 __might_sleep+0x95/0x190 kernel/sched/core.c:6013 __might_fault+0xab/0x1d0 mm/memory.c:4525 _copy_to_user+0x2c/0xc0 lib/usercopy.c:25 copy_to_user include/linux/uaccess.h:155 [inline] seq_read+0xcb4/0x13d0 fs/seq_file.c:279 proc_reg_read+0xef/0x170 fs/proc/inode.c:217 do_loop_readv_writev fs/read_write.c:673 [inline] do_iter_read+0x3db/0x5b0 fs/read_write.c:897 compat_readv+0x1bf/0x270 fs/read_write.c:1140 do_compat_preadv64+0xdc/0x100 fs/read_write.c:1189 C_SYSC_preadv fs/read_write.c:1209 [inline] compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1203 do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline] do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389 entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125 RIP: 0023:0xf7f73c79 RSP: 002b:00000000e574a15c EFLAGS: 00000292 ORIG_RAX: 000000000000014d RAX: ffffffffffffffda RBX: 000000000000000f RCX: 0000000020a3afb0 RDX: 0000000000000001 RSI: 0000000000000067 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 WARNING: CPU: 1 PID: 3195 at lib/usercopy.c:26 _copy_to_user+0xb5/0xc0 lib/usercopy.c:26 Reported-by: syzbot <bot+eceb3204562c41a438fa1f2335e0fe4f6886d669@syzkaller.appspotmail.com> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 4adfa79fc254efb7b0eb3cd58f62c2c3f805f1ba ]

When we dump the ip6mr mfc entries via proc, we initialize an iterator
with the table to dump but we don't clear the cache pointer which might
be initialized from a prior read on the same descriptor that ended. This
can result in lock imbalance (an unnecessary unlock) leading to other
crashes and hangs. Clear the cache pointer like ipmr does to fix the issue.
Thanks for the reliable reproducer.

Here's syzbot's trace:
 WARNING: bad unlock balance detected!
 4.15.0-rc3+ #128 Not tainted
 syzkaller971460/3195 is trying to release lock (mrt_lock) at:
 [<000000006898068d>] ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553
 but there are no more locks to release!

 other info that might help us debug this:
 1 lock held by syzkaller971460/3195:
  #0:  (&p->lock){+.+.}, at: [<00000000744a6565>] seq_read+0xd5/0x13d0
 fs/seq_file.c:165

 stack backtrace:
 CPU: 1 PID: 3195 Comm: syzkaller971460 Not tainted 4.15.0-rc3+ #128
 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
 Google 01/01/2011
 Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x257 lib/dump_stack.c:53
  print_unlock_imbalance_bug+0x12f/0x140 kernel/locking/lockdep.c:3561
  __lock_release kernel/locking/lockdep.c:3775 [inline]
  lock_release+0x5f9/0xda0 kernel/locking/lockdep.c:4023
  __raw_read_unlock include/linux/rwlock_api_smp.h:225 [inline]
  _raw_read_unlock+0x1a/0x30 kernel/locking/spinlock.c:255
  ipmr_mfc_seq_stop+0xe1/0x130 net/ipv6/ip6mr.c:553
  traverse+0x3bc/0xa00 fs/seq_file.c:135
  seq_read+0x96a/0x13d0 fs/seq_file.c:189
  proc_reg_read+0xef/0x170 fs/proc/inode.c:217
  do_loop_readv_writev fs/read_write.c:673 [inline]
  do_iter_read+0x3db/0x5b0 fs/read_write.c:897
  compat_readv+0x1bf/0x270 fs/read_write.c:1140
  do_compat_preadv64+0xdc/0x100 fs/read_write.c:1189
  C_SYSC_preadv fs/read_write.c:1209 [inline]
  compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1203
  do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
  do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
  entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125
 RIP: 0023:0xf7f73c79
 RSP: 002b:00000000e574a15c EFLAGS: 00000292 ORIG_RAX: 000000000000014d
 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 0000000020a3afb0
 RDX: 0000000000000001 RSI: 0000000000000067 RDI: 0000000000000000
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 BUG: sleeping function called from invalid context at lib/usercopy.c:25
 in_atomic(): 1, irqs_disabled(): 0, pid: 3195, name: syzkaller971460
 INFO: lockdep is turned off.
 CPU: 1 PID: 3195 Comm: syzkaller971460 Not tainted 4.15.0-rc3+ #128
 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
 Google 01/01/2011
 Call Trace:
  __dump_stack lib/dump_stack.c:17 [inline]
  dump_stack+0x194/0x257 lib/dump_stack.c:53
  ___might_sleep+0x2b2/0x470 kernel/sched/core.c:6060
  __might_sleep+0x95/0x190 kernel/sched/core.c:6013
  __might_fault+0xab/0x1d0 mm/memory.c:4525
  _copy_to_user+0x2c/0xc0 lib/usercopy.c:25
  copy_to_user include/linux/uaccess.h:155 [inline]
  seq_read+0xcb4/0x13d0 fs/seq_file.c:279
  proc_reg_read+0xef/0x170 fs/proc/inode.c:217
  do_loop_readv_writev fs/read_write.c:673 [inline]
  do_iter_read+0x3db/0x5b0 fs/read_write.c:897
  compat_readv+0x1bf/0x270 fs/read_write.c:1140
  do_compat_preadv64+0xdc/0x100 fs/read_write.c:1189
  C_SYSC_preadv fs/read_write.c:1209 [inline]
  compat_SyS_preadv+0x3b/0x50 fs/read_write.c:1203
  do_syscall_32_irqs_on arch/x86/entry/common.c:327 [inline]
  do_fast_syscall_32+0x3ee/0xf9d arch/x86/entry/common.c:389
  entry_SYSENTER_compat+0x51/0x60 arch/x86/entry/entry_64_compat.S:125
 RIP: 0023:0xf7f73c79
 RSP: 002b:00000000e574a15c EFLAGS: 00000292 ORIG_RAX: 000000000000014d
 RAX: ffffffffffffffda RBX: 000000000000000f RCX: 0000000020a3afb0
 RDX: 0000000000000001 RSI: 0000000000000067 RDI: 0000000000000000
 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 WARNING: CPU: 1 PID: 3195 at lib/usercopy.c:26 _copy_to_user+0xb5/0xc0
 lib/usercopy.c:26

Reported-by: syzbot <bot+eceb3204562c41a438fa1f2335e0fe4f6886d669@syzkaller.appspotmail.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ip6mr: fix notification device destruction 2017-05-03T04:19:54+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2017-04-21T17:42:16+00:00 bdeb026dfd9f27ec2e4a0ea97dab0e6e3d96e632 [ Upstream commit 723b929ca0f79c0796f160c2eeda4597ee98d2b8 ] Andrey Konovalov reported a BUG caused by the ip6mr code which is caused because we call unregister_netdevice_many for a device that is already being destroyed. In IPv4's ipmr that has been resolved by two commits long time ago by introducing the "notify" parameter to the delete function and avoiding the unregister when called from a notifier, so let's do the same for ip6mr. The trace from Andrey: ------------[ cut here ]------------ kernel BUG at net/core/dev.c:6813! invalid opcode: 0000 [#1] SMP KASAN Modules linked in: CPU: 1 PID: 1165 Comm: kworker/u4:3 Not tainted 4.11.0-rc7+ #251 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Workqueue: netns cleanup_net task: ffff880069208000 task.stack: ffff8800692d8000 RIP: 0010:rollback_registered_many+0x348/0xeb0 net/core/dev.c:6813 RSP: 0018:ffff8800692de7f0 EFLAGS: 00010297 RAX: ffff880069208000 RBX: 0000000000000002 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88006af90569 RBP: ffff8800692de9f0 R08: ffff8800692dec60 R09: 0000000000000000 R10: 0000000000000006 R11: 0000000000000000 R12: ffff88006af90070 R13: ffff8800692debf0 R14: dffffc0000000000 R15: ffff88006af90000 FS: 0000000000000000(0000) GS:ffff88006cb00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fe7e897d870 CR3: 00000000657e7000 CR4: 00000000000006e0 Call Trace: unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881 unregister_netdevice_many+0xc8/0x120 net/core/dev.c:7880 ip6mr_device_event+0x362/0x3f0 net/ipv6/ip6mr.c:1346 notifier_call_chain+0x145/0x2f0 kernel/notifier.c:93 __raw_notifier_call_chain kernel/notifier.c:394 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401 call_netdevice_notifiers_info+0x51/0x90 net/core/dev.c:1647 call_netdevice_notifiers net/core/dev.c:1663 rollback_registered_many+0x919/0xeb0 net/core/dev.c:6841 unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881 unregister_netdevice_many net/core/dev.c:7880 default_device_exit_batch+0x4fa/0x640 net/core/dev.c:8333 ops_exit_list.isra.4+0x100/0x150 net/core/net_namespace.c:144 cleanup_net+0x5a8/0xb40 net/core/net_namespace.c:463 process_one_work+0xc04/0x1c10 kernel/workqueue.c:2097 worker_thread+0x223/0x19c0 kernel/workqueue.c:2231 kthread+0x35e/0x430 kernel/kthread.c:231 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430 Code: 3c 32 00 0f 85 70 0b 00 00 48 b8 00 02 00 00 00 00 ad de 49 89 47 78 e9 93 fe ff ff 49 8d 57 70 49 8d 5f 78 eb 9e e8 88 7a 14 fe <0f> 0b 48 8b 9d 28 fe ff ff e8 7a 7a 14 fe 48 b8 00 00 00 00 00 RIP: rollback_registered_many+0x348/0xeb0 RSP: ffff8800692de7f0 ---[ end trace e0b29c57e9b3292c ]--- Reported-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Tested-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 723b929ca0f79c0796f160c2eeda4597ee98d2b8 ]

Andrey Konovalov reported a BUG caused by the ip6mr code which is caused
because we call unregister_netdevice_many for a device that is already
being destroyed. In IPv4's ipmr that has been resolved by two commits
long time ago by introducing the "notify" parameter to the delete
function and avoiding the unregister when called from a notifier, so
let's do the same for ip6mr.

The trace from Andrey:
------------[ cut here ]------------
kernel BUG at net/core/dev.c:6813!
invalid opcode: 0000 [#1] SMP KASAN
Modules linked in:
CPU: 1 PID: 1165 Comm: kworker/u4:3 Not tainted 4.11.0-rc7+ #251
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
01/01/2011
Workqueue: netns cleanup_net
task: ffff880069208000 task.stack: ffff8800692d8000
RIP: 0010:rollback_registered_many+0x348/0xeb0 net/core/dev.c:6813
RSP: 0018:ffff8800692de7f0 EFLAGS: 00010297
RAX: ffff880069208000 RBX: 0000000000000002 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88006af90569
RBP: ffff8800692de9f0 R08: ffff8800692dec60 R09: 0000000000000000
R10: 0000000000000006 R11: 0000000000000000 R12: ffff88006af90070
R13: ffff8800692debf0 R14: dffffc0000000000 R15: ffff88006af90000
FS:  0000000000000000(0000) GS:ffff88006cb00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe7e897d870 CR3: 00000000657e7000 CR4: 00000000000006e0
Call Trace:
 unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881
 unregister_netdevice_many+0xc8/0x120 net/core/dev.c:7880
 ip6mr_device_event+0x362/0x3f0 net/ipv6/ip6mr.c:1346
 notifier_call_chain+0x145/0x2f0 kernel/notifier.c:93
 __raw_notifier_call_chain kernel/notifier.c:394
 raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
 call_netdevice_notifiers_info+0x51/0x90 net/core/dev.c:1647
 call_netdevice_notifiers net/core/dev.c:1663
 rollback_registered_many+0x919/0xeb0 net/core/dev.c:6841
 unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881
 unregister_netdevice_many net/core/dev.c:7880
 default_device_exit_batch+0x4fa/0x640 net/core/dev.c:8333
 ops_exit_list.isra.4+0x100/0x150 net/core/net_namespace.c:144
 cleanup_net+0x5a8/0xb40 net/core/net_namespace.c:463
 process_one_work+0xc04/0x1c10 kernel/workqueue.c:2097
 worker_thread+0x223/0x19c0 kernel/workqueue.c:2231
 kthread+0x35e/0x430 kernel/kthread.c:231
 ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
Code: 3c 32 00 0f 85 70 0b 00 00 48 b8 00 02 00 00 00 00 ad de 49 89
47 78 e9 93 fe ff ff 49 8d 57 70 49 8d 5f 78 eb 9e e8 88 7a 14 fe <0f>
0b 48 8b 9d 28 fe ff ff e8 7a 7a 14 fe 48 b8 00 00 00 00 00
RIP: rollback_registered_many+0x348/0xeb0 RSP: ffff8800692de7f0
---[ end trace e0b29c57e9b3292c ]---

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipmr, ip6mr: fix scheduling while atomic and a deadlock with ipmr_get_route 2016-11-15T06:46:37+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2016-09-25T21:08:31+00:00 6eb0061fa630ae97c733a4dcbe3e23333ebe8626 [ Upstream commit 2cf750704bb6d7ed8c7d732e071dd1bc890ea5e8 ] Since the commit below the ipmr/ip6mr rtnl_unicast() code uses the portid instead of the previous dst_pid which was copied from in_skb's portid. Since the skb is new the portid is 0 at that point so the packets are sent to the kernel and we get scheduling while atomic or a deadlock (depending on where it happens) by trying to acquire rtnl two times. Also since this is RTM_GETROUTE, it can be triggered by a normal user. Here's the sleeping while atomic trace: [ 7858.212557] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620 [ 7858.212748] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0 [ 7858.212881] 2 locks held by swapper/0/0: [ 7858.213013] #0: (((&mrt->ipmr_expire_timer))){+.-...}, at: [<ffffffff810fbbf5>] call_timer_fn+0x5/0x350 [ 7858.213422] #1: (mfc_unres_lock){+.....}, at: [<ffffffff8161e005>] ipmr_expire_process+0x25/0x130 [ 7858.213807] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc7+ #179 [ 7858.213934] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014 [ 7858.214108] 0000000000000000 ffff88005b403c50 ffffffff813a7804 0000000000000000 [ 7858.214412] ffffffff81a1338e ffff88005b403c78 ffffffff810a4a72 ffffffff81a1338e [ 7858.214716] 000000000000026c 0000000000000000 ffff88005b403ca8 ffffffff810a4b9f [ 7858.215251] Call Trace: [ 7858.215412] <IRQ> [<ffffffff813a7804>] dump_stack+0x85/0xc1 [ 7858.215662] [<ffffffff810a4a72>] ___might_sleep+0x192/0x250 [ 7858.215868] [<ffffffff810a4b9f>] __might_sleep+0x6f/0x100 [ 7858.216072] [<ffffffff8165bea3>] mutex_lock_nested+0x33/0x4d0 [ 7858.216279] [<ffffffff815a7a5f>] ? netlink_lookup+0x25f/0x460 [ 7858.216487] [<ffffffff8157474b>] rtnetlink_rcv+0x1b/0x40 [ 7858.216687] [<ffffffff815a9a0c>] netlink_unicast+0x19c/0x260 [ 7858.216900] [<ffffffff81573c70>] rtnl_unicast+0x20/0x30 [ 7858.217128] [<ffffffff8161cd39>] ipmr_destroy_unres+0xa9/0xf0 [ 7858.217351] [<ffffffff8161e06f>] ipmr_expire_process+0x8f/0x130 [ 7858.217581] [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180 [ 7858.217785] [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180 [ 7858.217990] [<ffffffff810fbc95>] call_timer_fn+0xa5/0x350 [ 7858.218192] [<ffffffff810fbbf5>] ? call_timer_fn+0x5/0x350 [ 7858.218415] [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180 [ 7858.218656] [<ffffffff810fde10>] run_timer_softirq+0x260/0x640 [ 7858.218865] [<ffffffff8166379b>] ? __do_softirq+0xbb/0x54f [ 7858.219068] [<ffffffff816637c8>] __do_softirq+0xe8/0x54f [ 7858.219269] [<ffffffff8107a948>] irq_exit+0xb8/0xc0 [ 7858.219463] [<ffffffff81663452>] smp_apic_timer_interrupt+0x42/0x50 [ 7858.219678] [<ffffffff816625bc>] apic_timer_interrupt+0x8c/0xa0 [ 7858.219897] <EOI> [<ffffffff81055f16>] ? native_safe_halt+0x6/0x10 [ 7858.220165] [<ffffffff810d64dd>] ? trace_hardirqs_on+0xd/0x10 [ 7858.220373] [<ffffffff810298e3>] default_idle+0x23/0x190 [ 7858.220574] [<ffffffff8102a20f>] arch_cpu_idle+0xf/0x20 [ 7858.220790] [<ffffffff810c9f8c>] default_idle_call+0x4c/0x60 [ 7858.221016] [<ffffffff810ca33b>] cpu_startup_entry+0x39b/0x4d0 [ 7858.221257] [<ffffffff8164f995>] rest_init+0x135/0x140 [ 7858.221469] [<ffffffff81f83014>] start_kernel+0x50e/0x51b [ 7858.221670] [<ffffffff81f82120>] ? early_idt_handler_array+0x120/0x120 [ 7858.221894] [<ffffffff81f8243f>] x86_64_start_reservations+0x2a/0x2c [ 7858.222113] [<ffffffff81f8257c>] x86_64_start_kernel+0x13b/0x14a Fixes: 2942e9005056 ("[RTNETLINK]: Use rtnl_unicast() for rtnetlink unicasts") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 2cf750704bb6d7ed8c7d732e071dd1bc890ea5e8 ]

Since the commit below the ipmr/ip6mr rtnl_unicast() code uses the portid
instead of the previous dst_pid which was copied from in_skb's portid.
Since the skb is new the portid is 0 at that point so the packets are sent
to the kernel and we get scheduling while atomic or a deadlock (depending
on where it happens) by trying to acquire rtnl two times.
Also since this is RTM_GETROUTE, it can be triggered by a normal user.

Here's the sleeping while atomic trace:
[ 7858.212557] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:620
[ 7858.212748] in_atomic(): 1, irqs_disabled(): 0, pid: 0, name: swapper/0
[ 7858.212881] 2 locks held by swapper/0/0:
[ 7858.213013]  #0:  (((&mrt->ipmr_expire_timer))){+.-...}, at: [<ffffffff810fbbf5>] call_timer_fn+0x5/0x350
[ 7858.213422]  #1:  (mfc_unres_lock){+.....}, at: [<ffffffff8161e005>] ipmr_expire_process+0x25/0x130
[ 7858.213807] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.8.0-rc7+ #179
[ 7858.213934] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.7.5-20140531_083030-gandalf 04/01/2014
[ 7858.214108]  0000000000000000 ffff88005b403c50 ffffffff813a7804 0000000000000000
[ 7858.214412]  ffffffff81a1338e ffff88005b403c78 ffffffff810a4a72 ffffffff81a1338e
[ 7858.214716]  000000000000026c 0000000000000000 ffff88005b403ca8 ffffffff810a4b9f
[ 7858.215251] Call Trace:
[ 7858.215412]  <IRQ>  [<ffffffff813a7804>] dump_stack+0x85/0xc1
[ 7858.215662]  [<ffffffff810a4a72>] ___might_sleep+0x192/0x250
[ 7858.215868]  [<ffffffff810a4b9f>] __might_sleep+0x6f/0x100
[ 7858.216072]  [<ffffffff8165bea3>] mutex_lock_nested+0x33/0x4d0
[ 7858.216279]  [<ffffffff815a7a5f>] ? netlink_lookup+0x25f/0x460
[ 7858.216487]  [<ffffffff8157474b>] rtnetlink_rcv+0x1b/0x40
[ 7858.216687]  [<ffffffff815a9a0c>] netlink_unicast+0x19c/0x260
[ 7858.216900]  [<ffffffff81573c70>] rtnl_unicast+0x20/0x30
[ 7858.217128]  [<ffffffff8161cd39>] ipmr_destroy_unres+0xa9/0xf0
[ 7858.217351]  [<ffffffff8161e06f>] ipmr_expire_process+0x8f/0x130
[ 7858.217581]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.217785]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.217990]  [<ffffffff810fbc95>] call_timer_fn+0xa5/0x350
[ 7858.218192]  [<ffffffff810fbbf5>] ? call_timer_fn+0x5/0x350
[ 7858.218415]  [<ffffffff8161dfe0>] ? ipmr_net_init+0x180/0x180
[ 7858.218656]  [<ffffffff810fde10>] run_timer_softirq+0x260/0x640
[ 7858.218865]  [<ffffffff8166379b>] ? __do_softirq+0xbb/0x54f
[ 7858.219068]  [<ffffffff816637c8>] __do_softirq+0xe8/0x54f
[ 7858.219269]  [<ffffffff8107a948>] irq_exit+0xb8/0xc0
[ 7858.219463]  [<ffffffff81663452>] smp_apic_timer_interrupt+0x42/0x50
[ 7858.219678]  [<ffffffff816625bc>] apic_timer_interrupt+0x8c/0xa0
[ 7858.219897]  <EOI>  [<ffffffff81055f16>] ? native_safe_halt+0x6/0x10
[ 7858.220165]  [<ffffffff810d64dd>] ? trace_hardirqs_on+0xd/0x10
[ 7858.220373]  [<ffffffff810298e3>] default_idle+0x23/0x190
[ 7858.220574]  [<ffffffff8102a20f>] arch_cpu_idle+0xf/0x20
[ 7858.220790]  [<ffffffff810c9f8c>] default_idle_call+0x4c/0x60
[ 7858.221016]  [<ffffffff810ca33b>] cpu_startup_entry+0x39b/0x4d0
[ 7858.221257]  [<ffffffff8164f995>] rest_init+0x135/0x140
[ 7858.221469]  [<ffffffff81f83014>] start_kernel+0x50e/0x51b
[ 7858.221670]  [<ffffffff81f82120>] ? early_idt_handler_array+0x120/0x120
[ 7858.221894]  [<ffffffff81f8243f>] x86_64_start_reservations+0x2a/0x2c
[ 7858.222113]  [<ffffffff81f8257c>] x86_64_start_kernel+0x13b/0x14a

Fixes: 2942e9005056 ("[RTNETLINK]: Use rtnl_unicast() for rtnetlink unicasts")
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ipmr/ip6mr: Initialize the last assert time of mfc entries. 2016-07-11T16:31:11+00:00 Tom Goff thomas.goff@ll.mit.edu 2016-06-23T20:11:57+00:00 d05916086fa3e797b3806f1ec3c5a923adb3070e [ Upstream commit 70a0dec45174c976c64b4c8c1d0898581f759948 ] This fixes wrong-interface signaling on 32-bit platforms for entries created when jiffies > 2^31 + MFC_ASSERT_THRESH. Signed-off-by: Tom Goff <thomas.goff@ll.mit.edu> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 70a0dec45174c976c64b4c8c1d0898581f759948 ]

This fixes wrong-interface signaling on 32-bit platforms for entries
created when jiffies > 2^31 + MFC_ASSERT_THRESH.

Signed-off-by: Tom Goff <thomas.goff@ll.mit.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: ipmr, ip6mr: fix vif/tunnel failure race condition 2015-11-24T22:15:56+00:00 Nikolay Aleksandrov nikolay@cumulusnetworks.com 2015-11-24T16:09:30+00:00 fbdd29bfd2da979b7ac6a0084af56624156c1069 Since (at least) commit b17a7c179dd3 ("[NET]: Do sysfs registration as part of register_netdevice."), netdev_run_todo() deals only with unregistration, so we don't need to do the rtnl_unlock/lock cycle to finish registration when failing pimreg or dvmrp device creation. In fact that opens a race condition where someone can delete the device while rtnl is unlocked because it's fully registered. The problem gets worse when netlink support is introduced as there are more points of entry that can cause it and it also makes reusing that code correctly impossible. Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Reviewed-by: Cong Wang <cwang@twopensource.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Since (at least) commit b17a7c179dd3 ("[NET]: Do sysfs registration as
part of register_netdevice."), netdev_run_todo() deals only with
unregistration, so we don't need to do the rtnl_unlock/lock cycle to
finish registration when failing pimreg or dvmrp device creation. In
fact that opens a race condition where someone can delete the device
while rtnl is unlocked because it's fully registered. The problem gets
worse when netlink support is introduced as there are more points of entry
that can cause it and it also makes reusing that code correctly impossible.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Reviewed-by: Cong Wang <cwang@twopensource.com>
Signed-off-by: David S. Miller <davem@davemloft.net>