linux-toradex.git/net/ipv4, branch v6.9-rc5

inet: bring NLM_DONE out to a separate recv() again

2024-04-15T09:25:27+00:00

Commit under Fixes optimized the number of recv() calls
needed during RTM_GETROUTE dumps, but we got multiple
reports of applications hanging on recv() calls.
Applications expect that a route dump will be terminated
with a recv() reading an individual NLM_DONE message.

Coalescing NLM_DONE is perfectly legal in netlink,
but even tho reporters fixed the code in respective
projects, chances are it will take time for those
applications to get updated. So revert to old behavior
(for now)?

Old kernel (5.19):

 $ ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
            --dump getroute --json '{"rtm-family": 2}'
 Recv: read 692 bytes, 11 messages
   nl_len = 68 (52) nl_flags = 0x22 nl_type = 24
 ...
   nl_len = 60 (44) nl_flags = 0x22 nl_type = 24
 Recv: read 20 bytes, 1 messages
   nl_len = 20 (4) nl_flags = 0x2 nl_type = 3

Before (6.9-rc2):

 $ ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
            --dump getroute --json '{"rtm-family": 2}'
 Recv: read 712 bytes, 12 messages
   nl_len = 68 (52) nl_flags = 0x22 nl_type = 24
 ...
   nl_len = 60 (44) nl_flags = 0x22 nl_type = 24
   nl_len = 20 (4) nl_flags = 0x2 nl_type = 3

After:

 $ ./cli.py --dbg-small-recv 4096 --spec netlink/specs/rt_route.yaml \
            --dump getroute --json '{"rtm-family": 2}'
 Recv: read 692 bytes, 11 messages
   nl_len = 68 (52) nl_flags = 0x22 nl_type = 24
 ...
   nl_len = 60 (44) nl_flags = 0x22 nl_type = 24
 Recv: read 20 bytes, 1 messages
   nl_len = 20 (4) nl_flags = 0x2 nl_type = 3

Reported-by: Stefano Brivio 
Link: https://lore.kernel.org/all/20240315124808.033ff58d@elisabeth
Reported-by: Ilya Maximets 
Link: https://lore.kernel.org/all/02b50aae-f0e9-47a4-8365-a977a85975d3@ovn.org
Fixes: 4ce5dc9316de ("inet: switch inet_dump_fib() to RCU protection")
Signed-off-by: Jakub Kicinski 
Tested-by: Ilya Maximets 
Reviewed-by: David Ahern 
Signed-off-by: David S. Miller

netfilter: complete validation of user input

2024-04-11T02:42:56+00:00

In my recent commit, I missed that do_replace() handlers
use copy_from_sockptr() (which I fixed), followed
by unsafe copy_from_sockptr_offset() calls.

In all functions, we can perform the @optlen validation
before even calling xt_alloc_table_info() with the following
check:

if ((u64)optlen < (u64)tmp.size + sizeof(tmp))
        return -EINVAL;

Fixes: 0c83842df40f ("netfilter: validate user input for expected length")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Pablo Neira Ayuso 
Link: https://lore.kernel.org/r/20240409120741.3538135-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

ipv4/route: avoid unused-but-set-variable warning

2024-04-09T13:49:19+00:00

The log_martians variable is only used in an #ifdef, causing a 'make W=1'
warning with gcc:

net/ipv4/route.c: In function 'ip_rt_send_redirect':
net/ipv4/route.c:880:13: error: variable 'log_martians' set but not used [-Werror=unused-but-set-variable]

Change the #ifdef to an equivalent IS_ENABLED() to let the compiler
see where the variable is used.

Fixes: 30038fc61adf ("net: ip_rt_send_redirect() optimization")
Reviewed-by: David Ahern 
Signed-off-by: Arnd Bergmann 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20240408074219.3030256-2-arnd@kernel.org
Signed-off-by: Paolo Abeni

netfilter: validate user input for expected length

2024-04-04T16:39:52+00:00

I got multiple syzbot reports showing old bugs exposed
by BPF after commit 20f2505fb436 ("bpf: Try to avoid kzalloc
in cgroup/{s,g}etsockopt")

setsockopt() @optlen argument should be taken into account
before copying data.

 BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
 BUG: KASAN: slab-out-of-bounds in copy_from_sockptr include/linux/sockptr.h:55 [inline]
 BUG: KASAN: slab-out-of-bounds in do_replace net/ipv4/netfilter/ip_tables.c:1111 [inline]
 BUG: KASAN: slab-out-of-bounds in do_ipt_set_ctl+0x902/0x3dd0 net/ipv4/netfilter/ip_tables.c:1627
Read of size 96 at addr ffff88802cd73da0 by task syz-executor.4/7238

CPU: 1 PID: 7238 Comm: syz-executor.4 Not tainted 6.9.0-rc2-next-20240403-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 
  __dump_stack lib/dump_stack.c:88 [inline]
  dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
  print_address_description mm/kasan/report.c:377 [inline]
  print_report+0x169/0x550 mm/kasan/report.c:488
  kasan_report+0x143/0x180 mm/kasan/report.c:601
  kasan_check_range+0x282/0x290 mm/kasan/generic.c:189
  __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
  copy_from_sockptr_offset include/linux/sockptr.h:49 [inline]
  copy_from_sockptr include/linux/sockptr.h:55 [inline]
  do_replace net/ipv4/netfilter/ip_tables.c:1111 [inline]
  do_ipt_set_ctl+0x902/0x3dd0 net/ipv4/netfilter/ip_tables.c:1627
  nf_setsockopt+0x295/0x2c0 net/netfilter/nf_sockopt.c:101
  do_sock_setsockopt+0x3af/0x720 net/socket.c:2311
  __sys_setsockopt+0x1ae/0x250 net/socket.c:2334
  __do_sys_setsockopt net/socket.c:2343 [inline]
  __se_sys_setsockopt net/socket.c:2340 [inline]
  __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x72/0x7a
RIP: 0033:0x7fd22067dde9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd21f9ff0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 00007fd2207abf80 RCX: 00007fd22067dde9
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007fd2206ca47a R08: 0000000000000001 R09: 0000000000000000
R10: 0000000020000880 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd2207abf80 R15: 00007ffd2d0170d8
 

Allocated by task 7238:
  kasan_save_stack mm/kasan/common.c:47 [inline]
  kasan_save_track+0x3f/0x80 mm/kasan/common.c:68
  poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
  __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:387
  kasan_kmalloc include/linux/kasan.h:211 [inline]
  __do_kmalloc_node mm/slub.c:4069 [inline]
  __kmalloc_noprof+0x200/0x410 mm/slub.c:4082
  kmalloc_noprof include/linux/slab.h:664 [inline]
  __cgroup_bpf_run_filter_setsockopt+0xd47/0x1050 kernel/bpf/cgroup.c:1869
  do_sock_setsockopt+0x6b4/0x720 net/socket.c:2293
  __sys_setsockopt+0x1ae/0x250 net/socket.c:2334
  __do_sys_setsockopt net/socket.c:2343 [inline]
  __se_sys_setsockopt net/socket.c:2340 [inline]
  __x64_sys_setsockopt+0xb5/0xd0 net/socket.c:2340
 do_syscall_64+0xfb/0x240
 entry_SYSCALL_64_after_hwframe+0x72/0x7a

The buggy address belongs to the object at ffff88802cd73da0
 which belongs to the cache kmalloc-8 of size 8
The buggy address is located 0 bytes inside of
 allocated 1-byte region [ffff88802cd73da0, ffff88802cd73da1)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88802cd73020 pfn:0x2cd73
flags: 0xfff80000000000(node=0|zone=1|lastcpupid=0xfff)
page_type: 0xffffefff(slab)
raw: 00fff80000000000 ffff888015041280 dead000000000100 dead000000000122
raw: ffff88802cd73020 000000008080007f 00000001ffffefff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 5103, tgid 2119833701 (syz-executor.4), ts 5103, free_ts 70804600828
  set_page_owner include/linux/page_owner.h:32 [inline]
  post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1490
  prep_new_page mm/page_alloc.c:1498 [inline]
  get_page_from_freelist+0x2e7e/0x2f40 mm/page_alloc.c:3454
  __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4712
  __alloc_pages_node_noprof include/linux/gfp.h:244 [inline]
  alloc_pages_node_noprof include/linux/gfp.h:271 [inline]
  alloc_slab_page+0x5f/0x120 mm/slub.c:2249
  allocate_slab+0x5a/0x2e0 mm/slub.c:2412
  new_slab mm/slub.c:2465 [inline]
  ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3615
  __slab_alloc+0x58/0xa0 mm/slub.c:3705
  __slab_alloc_node mm/slub.c:3758 [inline]
  slab_alloc_node mm/slub.c:3936 [inline]
  __do_kmalloc_node mm/slub.c:4068 [inline]
  kmalloc_node_track_caller_noprof+0x286/0x450 mm/slub.c:4089
  kstrdup+0x3a/0x80 mm/util.c:62
  device_rename+0xb5/0x1b0 drivers/base/core.c:4558
  dev_change_name+0x275/0x860 net/core/dev.c:1232
  do_setlink+0xa4b/0x41f0 net/core/rtnetlink.c:2864
  __rtnl_newlink net/core/rtnetlink.c:3680 [inline]
  rtnl_newlink+0x180b/0x20a0 net/core/rtnetlink.c:3727
  rtnetlink_rcv_msg+0x89b/0x10d0 net/core/rtnetlink.c:6594
  netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2559
  netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline]
  netlink_unicast+0x7ea/0x980 net/netlink/af_netlink.c:1361
page last free pid 5146 tgid 5146 stack trace:
  reset_page_owner include/linux/page_owner.h:25 [inline]
  free_pages_prepare mm/page_alloc.c:1110 [inline]
  free_unref_page+0xd3c/0xec0 mm/page_alloc.c:2617
  discard_slab mm/slub.c:2511 [inline]
  __put_partials+0xeb/0x130 mm/slub.c:2980
  put_cpu_partial+0x17c/0x250 mm/slub.c:3055
  __slab_free+0x2ea/0x3d0 mm/slub.c:4254
  qlink_free mm/kasan/quarantine.c:163 [inline]
  qlist_free_all+0x9e/0x140 mm/kasan/quarantine.c:179
  kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
  __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:322
  kasan_slab_alloc include/linux/kasan.h:201 [inline]
  slab_post_alloc_hook mm/slub.c:3888 [inline]
  slab_alloc_node mm/slub.c:3948 [inline]
  __do_kmalloc_node mm/slub.c:4068 [inline]
  __kmalloc_node_noprof+0x1d7/0x450 mm/slub.c:4076
  kmalloc_node_noprof include/linux/slab.h:681 [inline]
  kvmalloc_node_noprof+0x72/0x190 mm/util.c:634
  bucket_table_alloc lib/rhashtable.c:186 [inline]
  rhashtable_rehash_alloc+0x9e/0x290 lib/rhashtable.c:367
  rht_deferred_worker+0x4e1/0x2440 lib/rhashtable.c:427
  process_one_work kernel/workqueue.c:3218 [inline]
  process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3299
  worker_thread+0x86d/0xd70 kernel/workqueue.c:3380
  kthread+0x2f0/0x390 kernel/kthread.c:388
  ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
  ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:243

Memory state around the buggy address:
 ffff88802cd73c80: 07 fc fc fc 05 fc fc fc 05 fc fc fc fa fc fc fc
 ffff88802cd73d00: fa fc fc fc fa fc fc fc fa fc fc fc fa fc fc fc
>ffff88802cd73d80: fa fc fc fc 01 fc fc fc fa fc fc fc fa fc fc fc
                               ^
 ffff88802cd73e00: fa fc fc fc fa fc fc fc 05 fc fc fc 07 fc fc fc
 ffff88802cd73e80: 07 fc fc fc 07 fc fc fc 07 fc fc fc 07 fc fc fc

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Pablo Neira Ayuso 
Link: https://lore.kernel.org/r/20240404122051.2303764-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

tcp: Fix bind() regression for v6-only wildcard and v4(-mapped-v6) non-wildcard addresses.

2024-03-29T21:48:38+00:00

Jianguo Wu reported another bind() regression introduced by bhash2.

Calling bind() for the following 3 addresses on the same port, the
3rd one should fail but now succeeds.

  1. 0.0.0.0 or ::ffff:0.0.0.0
  2. [::] w/ IPV6_V6ONLY
  3. IPv4 non-wildcard address or v4-mapped-v6 non-wildcard address

The first two bind() create tb2 like this:

  bhash2 -> tb2(:: w/ IPV6_V6ONLY) -> tb2(0.0.0.0)

The 3rd bind() will match with the IPv6 only wildcard address bucket
in inet_bind2_bucket_match_addr_any(), however, no conflicting socket
exists in the bucket.  So, inet_bhash2_conflict() will returns false,
and thus, inet_bhash2_addr_any_conflict() returns false consequently.

As a result, the 3rd bind() bypasses conflict check, which should be
done against the IPv4 wildcard address bucket.

So, in inet_bhash2_addr_any_conflict(), we must iterate over all buckets.

Note that we cannot add ipv6_only flag for inet_bind2_bucket as it
would confuse the following patetrn.

  1. [::] w/ SO_REUSE{ADDR,PORT} and IPV6_V6ONLY
  2. [::] w/ SO_REUSE{ADDR,PORT}
  3. IPv4 non-wildcard address or v4-mapped-v6 non-wildcard address

The first bind() would create a bucket with ipv6_only flag true,
the second bind() would add the [::] socket into the same bucket,
and the third bind() could succeed based on the wrong assumption
that ipv6_only bucket would not conflict with v4(-mapped-v6) address.

Fixes: 28044fc1d495 ("net: Add a bhash2 table hashed by port and address")
Diagnosed-by: Jianguo Wu 
Signed-off-by: Kuniyuki Iwashima 
Link: https://lore.kernel.org/r/20240326204251.51301-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski

tcp: Fix bind() regression for v6-only wildcard and v4-mapped-v6 non-wildcard addresses.

2024-03-29T21:48:38+00:00

Commit 5e07e672412b ("tcp: Use bhash2 for v4-mapped-v6 non-wildcard
address.") introduced bind() regression for v4-mapped-v6 address.

When we bind() the following two addresses on the same port, the 2nd
bind() should succeed but fails now.

  1. [::] w/ IPV6_ONLY
  2. ::ffff:127.0.0.1

After the chagne, v4-mapped-v6 uses bhash2 instead of bhash to
detect conflict faster, but I forgot to add a necessary change.

During the 2nd bind(), inet_bind2_bucket_match_addr_any() returns
the tb2 bucket of [::], and inet_bhash2_conflict() finally calls
inet_bind_conflict(), which returns true, meaning conflict.

  inet_bhash2_addr_any_conflict
  |- inet_bind2_bucket_match_addr_any  <-- return [::] bucket
  `- inet_bhash2_conflict
     `- __inet_bhash2_conflict <-- checks IPV6_ONLY for AF_INET
        |                          but not for v4-mapped-v6 address
        `- inet_bind_conflict  <-- does not check address

inet_bind_conflict() does not check socket addresses because
__inet_bhash2_conflict() is expected to do so.

However, it checks IPV6_V6ONLY attribute only against AF_INET
socket, and not for v4-mapped-v6 address.

As a result, v4-mapped-v6 address conflicts with v6-only wildcard
address.

To avoid that, let's add the missing test to use bhash2 for
v4-mapped-v6 address.

Fixes: 5e07e672412b ("tcp: Use bhash2 for v4-mapped-v6 non-wildcard address.")
Signed-off-by: Kuniyuki Iwashima 
Link: https://lore.kernel.org/r/20240326204251.51301-2-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski

erspan: make sure erspan_base_hdr is present in skb->head

2024-03-29T19:42:55+00:00

syzbot reported a problem in ip6erspan_rcv() [1]

Issue is that ip6erspan_rcv() (and erspan_rcv()) no longer make
sure erspan_base_hdr is present in skb linear part (skb->head)
before getting @ver field from it.

Add the missing pskb_may_pull() calls.

v2: Reload iph pointer in erspan_rcv() after pskb_may_pull()
    because skb->head might have changed.

[1]

 BUG: KMSAN: uninit-value in pskb_may_pull_reason include/linux/skbuff.h:2742 [inline]
 BUG: KMSAN: uninit-value in pskb_may_pull include/linux/skbuff.h:2756 [inline]
 BUG: KMSAN: uninit-value in ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline]
 BUG: KMSAN: uninit-value in gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610
  pskb_may_pull_reason include/linux/skbuff.h:2742 [inline]
  pskb_may_pull include/linux/skbuff.h:2756 [inline]
  ip6erspan_rcv net/ipv6/ip6_gre.c:541 [inline]
  gre_rcv+0x11f8/0x1930 net/ipv6/ip6_gre.c:610
  ip6_protocol_deliver_rcu+0x1d4c/0x2ca0 net/ipv6/ip6_input.c:438
  ip6_input_finish net/ipv6/ip6_input.c:483 [inline]
  NF_HOOK include/linux/netfilter.h:314 [inline]
  ip6_input+0x15d/0x430 net/ipv6/ip6_input.c:492
  ip6_mc_input+0xa7e/0xc80 net/ipv6/ip6_input.c:586
  dst_input include/net/dst.h:460 [inline]
  ip6_rcv_finish+0x955/0x970 net/ipv6/ip6_input.c:79
  NF_HOOK include/linux/netfilter.h:314 [inline]
  ipv6_rcv+0xde/0x390 net/ipv6/ip6_input.c:310
  __netif_receive_skb_one_core net/core/dev.c:5538 [inline]
  __netif_receive_skb+0x1da/0xa00 net/core/dev.c:5652
  netif_receive_skb_internal net/core/dev.c:5738 [inline]
  netif_receive_skb+0x58/0x660 net/core/dev.c:5798
  tun_rx_batched+0x3ee/0x980 drivers/net/tun.c:1549
  tun_get_user+0x5566/0x69e0 drivers/net/tun.c:2002
  tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
  call_write_iter include/linux/fs.h:2108 [inline]
  new_sync_write fs/read_write.c:497 [inline]
  vfs_write+0xb63/0x1520 fs/read_write.c:590
  ksys_write+0x20f/0x4c0 fs/read_write.c:643
  __do_sys_write fs/read_write.c:655 [inline]
  __se_sys_write fs/read_write.c:652 [inline]
  __x64_sys_write+0x93/0xe0 fs/read_write.c:652
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

Uninit was created at:
  slab_post_alloc_hook mm/slub.c:3804 [inline]
  slab_alloc_node mm/slub.c:3845 [inline]
  kmem_cache_alloc_node+0x613/0xc50 mm/slub.c:3888
  kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:577
  __alloc_skb+0x35b/0x7a0 net/core/skbuff.c:668
  alloc_skb include/linux/skbuff.h:1318 [inline]
  alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6504
  sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2795
  tun_alloc_skb drivers/net/tun.c:1525 [inline]
  tun_get_user+0x209a/0x69e0 drivers/net/tun.c:1846
  tun_chr_write_iter+0x3af/0x5d0 drivers/net/tun.c:2048
  call_write_iter include/linux/fs.h:2108 [inline]
  new_sync_write fs/read_write.c:497 [inline]
  vfs_write+0xb63/0x1520 fs/read_write.c:590
  ksys_write+0x20f/0x4c0 fs/read_write.c:643
  __do_sys_write fs/read_write.c:655 [inline]
  __se_sys_write fs/read_write.c:652 [inline]
  __x64_sys_write+0x93/0xe0 fs/read_write.c:652
 do_syscall_64+0xd5/0x1f0
 entry_SYSCALL_64_after_hwframe+0x6d/0x75

CPU: 1 PID: 5045 Comm: syz-executor114 Not tainted 6.9.0-rc1-syzkaller-00021-g962490525cff #0

Fixes: cb73ee40b1b3 ("net: ip_gre: use erspan key field for tunnel lookup")
Reported-by: syzbot+1c1cf138518bf0c53d68@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/netdev/000000000000772f2c0614b66ef7@google.com/
Signed-off-by: Eric Dumazet 
Cc: Lorenzo Bianconi 
Link: https://lore.kernel.org/r/20240328112248.1101491-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

udp: prevent local UDP tunnel packets from being GROed

2024-03-29T11:30:44+00:00

GRO has a fundamental issue with UDP tunnel packets as it can't detect
those in a foolproof way and GRO could happen before they reach the
tunnel endpoint. Previous commits have fixed issues when UDP tunnel
packets come from a remote host, but if those packets are issued locally
they could run into checksum issues.

If the inner packet has a partial checksum the information will be lost
in the GRO logic, either in udp4/6_gro_complete or in
udp_gro_complete_segment and packets will have an invalid checksum when
leaving the host.

Prevent local UDP tunnel packets from ever being GROed at the outer UDP
level.

Due to skb->encapsulation being wrongly used in some drivers this is
actually only preventing UDP tunnel packets with a partial checksum to
be GROed (see iptunnel_handle_offloads) but those were also the packets
triggering issues so in practice this should be sufficient.

Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.")
Fixes: 36707061d6ba ("udp: allow forwarding of plain (non-fraglisted) UDP GRO packets")
Suggested-by: Paolo Abeni 
Signed-off-by: Antoine Tenart 
Reviewed-by: Willem de Bruijn 
Signed-off-by: David S. Miller

udp: do not transition UDP GRO fraglist partial checksums to unnecessary

2024-03-29T11:30:44+00:00

UDP GRO validates checksums and in udp4/6_gro_complete fraglist packets
are converted to CHECKSUM_UNNECESSARY to avoid later checks. However
this is an issue for CHECKSUM_PARTIAL packets as they can be looped in
an egress path and then their partial checksums are not fixed.

Different issues can be observed, from invalid checksum on packets to
traces like:

  gen01: hw csum failure
  skb len=3008 headroom=160 headlen=1376 tailroom=0
  mac=(106,14) net=(120,40) trans=160
  shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0))
  csum(0xffff232e ip_summed=2 complete_sw=0 valid=0 level=0)
  hash(0x77e3d716 sw=1 l4=1) proto=0x86dd pkttype=0 iif=12
  ...

Fix this by only converting CHECKSUM_NONE packets to
CHECKSUM_UNNECESSARY by reusing __skb_incr_checksum_unnecessary. All
other checksum types are kept as-is, including CHECKSUM_COMPLETE as
fraglist packets being segmented back would have their skb->csum valid.

Fixes: 9fd1ff5d2ac7 ("udp: Support UDP fraglist GRO/GSO.")
Signed-off-by: Antoine Tenart 
Reviewed-by: Willem de Bruijn 
Signed-off-by: David S. Miller

gro: fix ownership transfer

2024-03-29T11:30:44+00:00

If packets are GROed with fraglist they might be segmented later on and
continue their journey in the stack. In skb_segment_list those skbs can
be reused as-is. This is an issue as their destructor was removed in
skb_gro_receive_list but not the reference to their socket, and then
they can't be orphaned. Fix this by also removing the reference to the
socket.

For example this could be observed,

  kernel BUG at include/linux/skbuff.h:3131!  (skb_orphan)
  RIP: 0010:ip6_rcv_core+0x11bc/0x19a0
  Call Trace:
   ipv6_list_rcv+0x250/0x3f0
   __netif_receive_skb_list_core+0x49d/0x8f0
   netif_receive_skb_list_internal+0x634/0xd40
   napi_complete_done+0x1d2/0x7d0
   gro_cell_poll+0x118/0x1f0

A similar construction is found in skb_gro_receive, apply the same
change there.

Fixes: 5e10da5385d2 ("skbuff: allow 'slow_gro' for skb carring sock reference")
Signed-off-by: Antoine Tenart 
Reviewed-by: Willem de Bruijn 
Signed-off-by: David S. Miller