linux-stable.git/drivers/net/vxlan, branch v6.14

vxlan: check vxlan_vnigroup_init() return value

2025-02-11T23:24:48+00:00

vxlan_init() must check vxlan_vnigroup_init() success
otherwise a crash happens later, spotted by syzbot.

Oops: general protection fault, probably for non-canonical address 0xdffffc000000002c: 0000 [#1] PREEMPT SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000160-0x0000000000000167]
CPU: 0 UID: 0 PID: 7313 Comm: syz-executor147 Not tainted 6.14.0-rc1-syzkaller-00276-g69b54314c975 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
 RIP: 0010:vxlan_vnigroup_uninit+0x89/0x500 drivers/net/vxlan/vxlan_vnifilter.c:912
Code: 00 48 8b 44 24 08 4c 8b b0 98 41 00 00 49 8d 86 60 01 00 00 48 89 c2 48 89 44 24 10 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 4d 04 00 00 49 8b 86 60 01 00 00 48 ba 00 00 00
RSP: 0018:ffffc9000cc1eea8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000001 RCX: ffffffff8672effb
RDX: 000000000000002c RSI: ffffffff8672ecb9 RDI: ffff8880461b4f18
RBP: ffff8880461b4ef4 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000020000
R13: ffff8880461b0d80 R14: 0000000000000000 R15: dffffc0000000000
FS:  00007fecfa95d6c0(0000) GS:ffff88806a600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fecfa95cfb8 CR3: 000000004472c000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
  vxlan_uninit+0x1ab/0x200 drivers/net/vxlan/vxlan_core.c:2942
  unregister_netdevice_many_notify+0x12d6/0x1f30 net/core/dev.c:11824
  unregister_netdevice_many net/core/dev.c:11866 [inline]
  unregister_netdevice_queue+0x307/0x3f0 net/core/dev.c:11736
  register_netdevice+0x1829/0x1eb0 net/core/dev.c:10901
  __vxlan_dev_create+0x7c6/0xa30 drivers/net/vxlan/vxlan_core.c:3981
  vxlan_newlink+0xd1/0x130 drivers/net/vxlan/vxlan_core.c:4407
  rtnl_newlink_create net/core/rtnetlink.c:3795 [inline]
  __rtnl_newlink net/core/rtnetlink.c:3906 [inline]

Fixes: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device")
Reported-by: syzbot+6a9624592218c2c5e7aa@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/67a9d9b4.050a0220.110943.002d.GAE@google.com/T/#u
Signed-off-by: Eric Dumazet 
Cc: Roopa Prabhu 
Reviewed-by: Ido Schimmel 
Link: https://patch.msgid.link/20250210105242.883482-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

vxlan: Fix uninit-value in vxlan_vnifilter_dump()

2025-01-27T22:53:13+00:00

KMSAN reported an uninit-value access in vxlan_vnifilter_dump() [1].

If the length of the netlink message payload is less than
sizeof(struct tunnel_msg), vxlan_vnifilter_dump() accesses bytes
beyond the message. This can lead to uninit-value access. Fix this by
returning an error in such situations.

[1]
BUG: KMSAN: uninit-value in vxlan_vnifilter_dump+0x328/0x920 drivers/net/vxlan/vxlan_vnifilter.c:422
 vxlan_vnifilter_dump+0x328/0x920 drivers/net/vxlan/vxlan_vnifilter.c:422
 rtnl_dumpit+0xd5/0x2f0 net/core/rtnetlink.c:6786
 netlink_dump+0x93e/0x15f0 net/netlink/af_netlink.c:2317
 __netlink_dump_start+0x716/0xd60 net/netlink/af_netlink.c:2432
 netlink_dump_start include/linux/netlink.h:340 [inline]
 rtnetlink_dump_start net/core/rtnetlink.c:6815 [inline]
 rtnetlink_rcv_msg+0x1256/0x14a0 net/core/rtnetlink.c:6882
 netlink_rcv_skb+0x467/0x660 net/netlink/af_netlink.c:2542
 rtnetlink_rcv+0x35/0x40 net/core/rtnetlink.c:6944
 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline]
 netlink_unicast+0xed6/0x1290 net/netlink/af_netlink.c:1347
 netlink_sendmsg+0x1092/0x1230 net/netlink/af_netlink.c:1891
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg+0x330/0x3d0 net/socket.c:726
 ____sys_sendmsg+0x7f4/0xb50 net/socket.c:2583
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2637
 __sys_sendmsg net/socket.c:2669 [inline]
 __do_sys_sendmsg net/socket.c:2674 [inline]
 __se_sys_sendmsg net/socket.c:2672 [inline]
 __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2672
 x64_sys_call+0x3878/0x3d90 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd9/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4110 [inline]
 slab_alloc_node mm/slub.c:4153 [inline]
 kmem_cache_alloc_node_noprof+0x800/0xe80 mm/slub.c:4205
 kmalloc_reserve+0x13b/0x4b0 net/core/skbuff.c:587
 __alloc_skb+0x347/0x7d0 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1323 [inline]
 netlink_alloc_large_skb+0xa5/0x280 net/netlink/af_netlink.c:1196
 netlink_sendmsg+0xac9/0x1230 net/netlink/af_netlink.c:1866
 sock_sendmsg_nosec net/socket.c:711 [inline]
 __sock_sendmsg+0x330/0x3d0 net/socket.c:726
 ____sys_sendmsg+0x7f4/0xb50 net/socket.c:2583
 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2637
 __sys_sendmsg net/socket.c:2669 [inline]
 __do_sys_sendmsg net/socket.c:2674 [inline]
 __se_sys_sendmsg net/socket.c:2672 [inline]
 __x64_sys_sendmsg+0x211/0x3e0 net/socket.c:2672
 x64_sys_call+0x3878/0x3d90 arch/x86/include/generated/asm/syscalls_64.h:47
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xd9/0x1d0 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

CPU: 0 UID: 0 PID: 30991 Comm: syz.4.10630 Not tainted 6.12.0-10694-gc44daa7e3c73 #29
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-3.fc41 04/01/2014

Fixes: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device")
Reported-by: syzkaller 
Signed-off-by: Shigeru Yoshida 
Reviewed-by: Ido Schimmel 
Link: https://patch.msgid.link/20250123145746.785768-1-syoshida@redhat.com
Signed-off-by: Jakub Kicinski

net: vxlan: rename SKB_DROP_REASON_VXLAN_NO_REMOTE

2024-12-23T18:11:04+00:00

The SKB_DROP_REASON_VXLAN_NO_REMOTE skb drop reason was introduced in
the specific context of vxlan. As it turns out, there are similar cases
when a packet needs to be dropped in other parts of the network stack,
such as the bridge module.

Rename SKB_DROP_REASON_VXLAN_NO_REMOTE and give it a more generic name,
so that it can be used in other parts of the network stack. This is not
a functional change, and the numeric value of the drop reason even
remains unchanged.

Signed-off-by: Radu Rendec 
Reviewed-by: Ido Schimmel 
Acked-by: Nikolay Aleksandrov 
Link: https://patch.msgid.link/20241219163606.717758-2-rrendec@redhat.com
Signed-off-by: Jakub Kicinski

rtnetlink: add ndo_fdb_dump_context

2024-12-11T02:32:32+00:00

rtnl_fdb_dump() and various ndo_fdb_dump() helpers share
a hidden layout of cb->ctx.

Before switching rtnl_fdb_dump() to for_each_netdev_dump()
in the following patch, make this more explicit.

Signed-off-by: Eric Dumazet 
Reviewed-by: Ido Schimmel 
Reviewed-by: Kuniyuki Iwashima 
Link: https://patch.msgid.link/20241209100747.2269613-2-edumazet@google.com
Signed-off-by: Jakub Kicinski

vxlan: Add an attribute to make VXLAN header validation configurable

2024-12-09T22:47:05+00:00

The set of bits that the VXLAN netdevice currently considers reserved is
defined by the features enabled at the netdevice construction. In order to
make this configurable, add an attribute, IFLA_VXLAN_RESERVED_BITS. The
payload is a pair of big-endian u32's covering the VXLAN header. This is
validated against the set of flags used by the various enabled VXLAN
features, and attempts to override bits used by an enabled feature are
bounced.

Signed-off-by: Petr Machata 
Reviewed-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Link: https://patch.msgid.link/c657275e5ceed301e62c69fe8e559e32909442e2.1733412063.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski

vxlan: vxlan_rcv(): Drop unparsed

2024-12-09T22:47:04+00:00

The code currently validates the VXLAN header in two ways: first by
comparing it with the set of reserved bits, constructed ahead of time
during the netdevice construction; and second by gradually clearing the
bits off a separate copy of VXLAN header, "unparsed". Drop the latter
validation method.

Signed-off-by: Petr Machata 
Reviewed-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Link: https://patch.msgid.link/4559f16c5664c189b3a4ee6f5da91f552ad4821c.1733412063.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski

vxlan: Bump error counters for header mismatches

2024-12-09T22:47:04+00:00

The VXLAN driver so far has not increased the error counters for packets
that set reserved bits. It does so for other packet errors, so do it for
this case as well.

Signed-off-by: Petr Machata 
Reviewed-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Link: https://patch.msgid.link/d096084167d56706d620afe5136cf37a2d34d1b9.1733412063.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski

vxlan: Track reserved bits explicitly as part of the configuration

2024-12-09T22:47:04+00:00

In order to make it possible to configure which bits in VXLAN header should
be considered reserved, introduce a new field vxlan_config::reserved_bits.
Have it cover the whole header, except for the VNI-present bit and the bits
for VNI itself, and have individual enabled features clear more bits off
reserved_bits.

(This is expressed as first constructing a used_bits set, and then
inverting it to get the reserved_bits. The set of used_bits will be useful
on its own for validation of user-set reserved_bits in a following patch.)

The patch also moves a comment relevant to the validation from the unparsed
validation site up to the new site. Logically this patch should add the new
comment, and a later patch that removes the unparsed bits would remove the
old comment. But keeping both legs in the same patch is better from the
history spelunking point of view.

Signed-off-by: Petr Machata 
Reviewed-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Link: https://patch.msgid.link/984dbf98d5940d3900268dbffaf70961f731d4a4.1733412063.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski

vxlan: vxlan_rcv(): Extract vxlan_hdr(skb) to a named variable

2024-12-09T22:47:03+00:00

Having a named reference to the VXLAN header is more handy than having to
conjure it anew through vxlan_hdr() on every use. Add a new variable and
convert several open-coded sites.

Additionally, convert one "unparsed" use to the new variable as well. Thus
the only "unparsed" uses that remain are the flag-clearing and the header
validity check at the end.

Signed-off-by: Petr Machata 
Reviewed-by: Ido Schimmel 
Reviewed-by: Mateusz Polchlopek 
Reviewed-by: Nikolay Aleksandrov 
Link: https://patch.msgid.link/2a0a940e883c435a0fdbcdc1d03c4858957ad00e.1733412063.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski

vxlan: vxlan_rcv() callees: Drop the unparsed argument

2024-12-09T22:47:03+00:00

The functions vxlan_remcsum() and vxlan_parse_gbp_hdr() take both the SKB
and the unparsed VXLAN header. Now that unparsed adjustment is handled
directly by vxlan_rcv(), drop this argument, and have the function derive
it from the SKB on its own.

vxlan_parse_gpe_proto() does not take SKB, so keep the header parameter.
However const it so that it's clear that the intention is that it does not
get changed.

Signed-off-by: Petr Machata 
Reviewed-by: Ido Schimmel 
Reviewed-by: Nikolay Aleksandrov 
Link: https://patch.msgid.link/5ea651f4e06485ba1a84a8eb556a457c39f0dfd4.1733412063.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski