linux-stable.git/drivers/net/ppp, branch v4.4.301

ppp: ensure minimum packet size in ppp_write()

2022-01-27T07:46:15+00:00

[ Upstream commit 44073187990d5629804ce0627525f6ea5cfef171 ]

It seems pretty clear ppp layer assumed user space
would always be kind to provide enough data
in their write() to a ppp device.

This patch makes sure user provides at least
2 bytes.

It adds PPP_PROTO_LEN macro that could replace
in net-next many occurrences of hard-coded 2 value.

I replaced only one occurrence to ease backports
to stable kernels.

The bug manifests in the following report:

BUG: KMSAN: uninit-value in ppp_send_frame+0x28d/0x27c0 drivers/net/ppp/ppp_generic.c:1740
 ppp_send_frame+0x28d/0x27c0 drivers/net/ppp/ppp_generic.c:1740
 __ppp_xmit_process+0x23e/0x4b0 drivers/net/ppp/ppp_generic.c:1640
 ppp_xmit_process+0x1fe/0x480 drivers/net/ppp/ppp_generic.c:1661
 ppp_write+0x5cb/0x5e0 drivers/net/ppp/ppp_generic.c:513
 do_iter_write+0xb0c/0x1500 fs/read_write.c:853
 vfs_writev fs/read_write.c:924 [inline]
 do_writev+0x645/0xe00 fs/read_write.c:967
 __do_sys_writev fs/read_write.c:1040 [inline]
 __se_sys_writev fs/read_write.c:1037 [inline]
 __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:524 [inline]
 slab_alloc_node mm/slub.c:3251 [inline]
 __kmalloc_node_track_caller+0xe0c/0x1510 mm/slub.c:4974
 kmalloc_reserve net/core/skbuff.c:354 [inline]
 __alloc_skb+0x545/0xf90 net/core/skbuff.c:426
 alloc_skb include/linux/skbuff.h:1126 [inline]
 ppp_write+0x11d/0x5e0 drivers/net/ppp/ppp_generic.c:501
 do_iter_write+0xb0c/0x1500 fs/read_write.c:853
 vfs_writev fs/read_write.c:924 [inline]
 do_writev+0x645/0xe00 fs/read_write.c:967
 __do_sys_writev fs/read_write.c:1040 [inline]
 __se_sys_writev fs/read_write.c:1037 [inline]
 __x64_sys_writev+0xe5/0x120 fs/read_write.c:1037
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x54/0xd0 arch/x86/entry/common.c:82
 entry_SYSCALL_64_after_hwframe+0x44/0xae

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet 
Cc: Paul Mackerras 
Cc: linux-ppp@vger.kernel.org
Reported-by: syzbot 
Acked-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

pppoe: only process PADT targeted at local interfaces

2020-06-11T07:21:38+00:00

We don't want to disconnect a session because of a stray PADT arriving
while the interface is in promiscuous mode.
Furthermore, multicast and broadcast packets make no sense here, so
only PACKET_HOST is accepted.

Reported-by: David Balažic 
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller

ppp: Adjust indentation into ppp_async_input

2020-02-14T21:29:59+00:00

commit 08cbc75f96029d3092664213a844a5e25523aa35 upstream.

Clang warns:

../drivers/net/ppp/ppp_async.c:877:6: warning: misleading indentation;
statement is not part of the previous 'if' [-Wmisleading-indentation]
                                ap->rpkt = skb;
                                ^
../drivers/net/ppp/ppp_async.c:875:5: note: previous statement is here
                                if (!skb)
                                ^
1 warning generated.

This warning occurs because there is a space before the tab on this
line. Clean up this entire block's indentation so that it is consistent
with the Linux kernel coding style and clang no longer warns.

Fixes: 6722e78c9005 ("[PPP]: handle misaligned accesses")
Link: https://github.com/ClangBuiltLinux/linux/issues/800
Signed-off-by: Nathan Chancellor 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

compat_ioctl: pppoe: fix PPPOEIOCSFWD handling

2019-08-11T10:20:46+00:00

[ Upstream commit 055d88242a6046a1ceac3167290f054c72571cd9 ]

Support for handling the PPPOEIOCSFWD ioctl in compat mode was added in
linux-2.5.69 along with hundreds of other commands, but was always broken
sincen only the structure is compatible, but the command number is not,
due to the size being sizeof(size_t), or at first sizeof(sizeof((struct
sockaddr_pppox)), which is different on 64-bit architectures.

Guillaume Nault adds:

  And the implementation was broken until 2016 (see 29e73269aa4d ("pppoe:
  fix reference counting in PPPoE proxy")), and nobody ever noticed. I
  should probably have removed this ioctl entirely instead of fixing it.
  Clearly, it has never been used.

Fix it by adding a compat_ioctl handler for all pppoe variants that
translates the command number and then calls the regular ioctl function.

All other ioctl commands handled by pppoe are compatible between 32-bit
and 64-bit, and require compat_ptr() conversion.

This should apply to all stable kernels.

Acked-by: Guillaume Nault 
Signed-off-by: Arnd Bergmann 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ppp: mppe: Add softdep to arc4

2019-07-21T07:07:13+00:00

[ Upstream commit aad1dcc4f011ea409850e040363dff1e59aa4175 ]

The arc4 crypto is mandatory at ppp_mppe probe time, so let's put a
softdep line, so that the corresponding module gets prepared
gracefully.  Without this, a simple inclusion to initrd via dracut
failed due to the missing dependency, for example.

Signed-off-by: Takashi Iwai 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

ppp: deflate: Fix possible crash in deflate_init

2019-06-11T10:23:43+00:00

[ Upstream commit 3ebe1bca58c85325c97a22d4fc3f5b5420752e6f ]

BUG: unable to handle kernel paging request at ffffffffa018f000
PGD 3270067 P4D 3270067 PUD 3271063 PMD 2307eb067 PTE 0
Oops: 0000 [#1] PREEMPT SMP
CPU: 0 PID: 4138 Comm: modprobe Not tainted 5.1.0-rc7+ #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014
RIP: 0010:ppp_register_compressor+0x3e/0xd0 [ppp_generic]
Code: 98 4a 3f e2 48 8b 15 c1 67 00 00 41 8b 0c 24 48 81 fa 40 f0 19 a0
75 0e eb 35 48 8b 12 48 81 fa 40 f0 19 a0 74
RSP: 0018:ffffc90000d93c68 EFLAGS: 00010287
RAX: ffffffffa018f000 RBX: ffffffffa01a3000 RCX: 000000000000001a
RDX: ffff888230c750a0 RSI: 0000000000000000 RDI: ffffffffa019f000
RBP: ffffc90000d93c80 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffa0194080
R13: ffff88822ee1a700 R14: 0000000000000000 R15: ffffc90000d93e78
FS:  00007f2339557540(0000) GS:ffff888237a00000(0000)
knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffa018f000 CR3: 000000022bde4000 CR4: 00000000000006f0
Call Trace:
 ? 0xffffffffa01a3000
 deflate_init+0x11/0x1000 [ppp_deflate]
 ? 0xffffffffa01a3000
 do_one_initcall+0x6c/0x3cc
 ? kmem_cache_alloc_trace+0x248/0x3b0
 do_init_module+0x5b/0x1f1
 load_module+0x1db1/0x2690
 ? m_show+0x1d0/0x1d0
 __do_sys_finit_module+0xc5/0xd0
 __x64_sys_finit_module+0x15/0x20
 do_syscall_64+0x6b/0x1d0
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

If ppp_deflate fails to register in deflate_init,
module initialization failed out, however
ppp_deflate_draft may has been regiestred and not
unregistered before return.
Then the seconed modprobe will trigger crash like this.

Reported-by: Hulk Robot 
Signed-off-by: YueHaibing 
Acked-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

pptp: dst_release sk_dst_cache in pptp_sock_destruct

2019-03-23T07:44:30+00:00

[ Upstream commit 9417d81f4f8adfe20a12dd1fadf73a618cbd945d ]

sk_setup_caps() is called to set sk->sk_dst_cache in pptp_connect,
so we have to dst_release(sk->sk_dst_cache) in pptp_sock_destruct,
otherwise, the dst refcnt will leak.

It can be reproduced by this syz log:

  r1 = socket$pptp(0x18, 0x1, 0x2)
  bind$pptp(r1, &(0x7f0000000100)={0x18, 0x2, {0x0, @local}}, 0x1e)
  connect$pptp(r1, &(0x7f0000000000)={0x18, 0x2, {0x3, @remote}}, 0x1e)

Consecutive dmesg warnings will occur:

  unregister_netdevice: waiting for lo to become free. Usage count = 1

v1->v2:
  - use rcu_dereference_protected() instead of rcu_dereference_check(),
    as suggested by Eric.

Fixes: 00959ade36ac ("PPTP: PPP over IPv4 (Point-to-Point Tunneling Protocol)")
Reported-by: Xiumei Mu 
Signed-off-by: Xin Long 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Fix usage of pskb_trim_rcsum

2019-02-06T18:43:02+00:00

[ Upstream commit 6c57f0458022298e4da1729c67bd33ce41c14e7a ]

In certain cases, pskb_trim_rcsum() may change skb pointers.
Reinitialize header pointers afterwards to avoid potential
use-after-frees. Add a note in the documentation of
pskb_trim_rcsum(). Found by KASAN.

Signed-off-by: Ross Lagerwall 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

pppoe: check sockaddr length in pppoe_connect()

2018-04-29T05:50:05+00:00

[ Upstream commit a49e2f5d5fb141884452ddb428f551b123d436b5 ]

We must validate sockaddr_len, otherwise userspace can pass fewer data
than we expect and we end up accessing invalid data.

Fixes: 224cf5ad14c0 ("ppp: Move the PPP drivers")
Reported-by: syzbot+4f03bdf92fdf9ef5ddab@syzkaller.appspotmail.com
Signed-off-by: Guillaume Nault 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

pptp: remove a buggy dst release in pptp_connect()

2018-04-13T17:50:25+00:00

[ Upstream commit bfacfb457b36911a10140b8cb3ce76a74883ac5a ]

Once dst has been cached in socket via sk_setup_caps(),
it is illegal to call ip_rt_put() (or dst_release()),
since sk_setup_caps() did not change dst refcount.

We can still dereference it since we hold socket lock.

Caugth by syzbot :

BUG: KASAN: use-after-free in atomic_dec_return include/asm-generic/atomic-instrumented.h:198 [inline]
BUG: KASAN: use-after-free in dst_release+0x27/0xa0 net/core/dst.c:185
Write of size 4 at addr ffff8801c54dc040 by task syz-executor4/20088

CPU: 1 PID: 20088 Comm: syz-executor4 Not tainted 4.16.0+ #376
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+0x1a7/0x27d lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report+0x23c/0x360 mm/kasan/report.c:412
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
 kasan_check_write+0x14/0x20 mm/kasan/kasan.c:278
 atomic_dec_return include/asm-generic/atomic-instrumented.h:198 [inline]
 dst_release+0x27/0xa0 net/core/dst.c:185
 sk_dst_set include/net/sock.h:1812 [inline]
 sk_dst_reset include/net/sock.h:1824 [inline]
 sock_setbindtodevice net/core/sock.c:610 [inline]
 sock_setsockopt+0x431/0x1b20 net/core/sock.c:707
 SYSC_setsockopt net/socket.c:1845 [inline]
 SyS_setsockopt+0x2ff/0x360 net/socket.c:1828
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4552d9
RSP: 002b:00007f4878126c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007f48781276d4 RCX: 00000000004552d9
RDX: 0000000000000019 RSI: 0000000000000001 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000010 R09: 0000000000000000
R10: 00000000200010c0 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000526 R14: 00000000006fac30 R15: 0000000000000000

Allocated by task 20088:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:552
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3542
 dst_alloc+0x11f/0x1a0 net/core/dst.c:104
 rt_dst_alloc+0xe9/0x540 net/ipv4/route.c:1520
 __mkroute_output net/ipv4/route.c:2265 [inline]
 ip_route_output_key_hash_rcu+0xa49/0x2c60 net/ipv4/route.c:2493
 ip_route_output_key_hash+0x20b/0x370 net/ipv4/route.c:2322
 __ip_route_output_key include/net/route.h:126 [inline]
 ip_route_output_flow+0x26/0xa0 net/ipv4/route.c:2577
 ip_route_output_ports include/net/route.h:163 [inline]
 pptp_connect+0xa84/0x1170 drivers/net/ppp/pptp.c:453
 SYSC_connect+0x213/0x4a0 net/socket.c:1639
 SyS_connect+0x24/0x30 net/socket.c:1620
 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 20082:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527
 __cache_free mm/slab.c:3486 [inline]
 kmem_cache_free+0x83/0x2a0 mm/slab.c:3744
 dst_destroy+0x266/0x380 net/core/dst.c:140
 dst_destroy_rcu+0x16/0x20 net/core/dst.c:153
 __rcu_reclaim kernel/rcu/rcu.h:178 [inline]
 rcu_do_batch kernel/rcu/tree.c:2675 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2930 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2897 [inline]
 rcu_process_callbacks+0xd6c/0x17b0 kernel/rcu/tree.c:2914
 __do_softirq+0x2d7/0xb85 kernel/softirq.c:285

The buggy address belongs to the object at ffff8801c54dc000
 which belongs to the cache ip_dst_cache of size 168
The buggy address is located 64 bytes inside of
 168-byte region [ffff8801c54dc000, ffff8801c54dc0a8)
The buggy address belongs to the page:
page:ffffea0007153700 count:1 mapcount:0 mapping:ffff8801c54dc000 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801c54dc000 0000000000000000 0000000100000010
raw: ffffea0006b34b20 ffffea0006b6c1e0 ffff8801d674a1c0 0000000000000000
page dumped because: kasan: bad access detected

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman