linux-stable.git/net/ipv6, branch v6.1.73

ipv6: remove max_size check inline with ipv4

2024-01-15T17:54:51+00:00

commit af6d10345ca76670c1b7c37799f0d5576ccef277 upstream.

In ip6_dst_gc() replace:

  if (entries > gc_thresh)

With:

  if (entries > ops->gc_thresh)

Sending Ipv6 packets in a loop via a raw socket triggers an issue where a
route is cloned by ip6_rt_cache_alloc() for each packet sent. This quickly
consumes the Ipv6 max_size threshold which defaults to 4096 resulting in
these warnings:

[1]   99.187805] dst_alloc: 7728 callbacks suppressed
[2] Route cache is full: consider increasing sysctl net.ipv6.route.max_size.
.
.
[300] Route cache is full: consider increasing sysctl net.ipv6.route.max_size.

When this happens the packet is dropped and sendto() gets a network is
unreachable error:

remaining pkt 200557 errno 101
remaining pkt 196462 errno 101
.
.
remaining pkt 126821 errno 101

Implement David Aherns suggestion to remove max_size check seeing that Ipv6
has a GC to manage memory usage. Ipv4 already does not check max_size.

Here are some memory comparisons for Ipv4 vs Ipv6 with the patch:

Test by running 5 instances of a program that sends UDP packets to a raw
socket 5000000 times. Compare Ipv4 and Ipv6 performance with a similar
program.

Ipv4:

Before test:

MemFree:        29427108 kB
Slab:             237612 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        2881   3990    192   42    2 : tunables    0    0    0

During test:

MemFree:        29417608 kB
Slab:             247712 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache       44394  44394    192   42    2 : tunables    0    0    0

After test:

MemFree:        29422308 kB
Slab:             238104 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

Ipv6 with patch:

Errno 101 errors are not observed anymore with the patch.

Before test:

MemFree:        29422308 kB
Slab:             238104 kB

ip6_dst_cache       1912   2528    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

During Test:

MemFree:        29431516 kB
Slab:             240940 kB

ip6_dst_cache      11980  12064    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

After Test:

MemFree:        29441816 kB
Slab:             238132 kB

ip6_dst_cache       1902   2432    256   32    2 : tunables    0    0    0
xfrm_dst_cache         0      0    320   25    2 : tunables    0    0    0
ip_dst_cache        3048   4116    192   42    2 : tunables    0    0    0

Tested-by: Andrea Mayer 
Signed-off-by: Jon Maxwell 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20230112012532.311021-1-jmaxwell37@gmail.com
Signed-off-by: Jakub Kicinski 
Cc: "Jitindar Singh, Suraj" 
Signed-off-by: Greg Kroah-Hartman

udp: annotate data-races around udp->encap_type

2024-01-10T16:10:28+00:00

[ Upstream commit 70a36f571362a8de8b8c02d21ae524fc776287f2 ]

syzbot/KCSAN complained about UDP_ENCAP_L2TPINUDP setsockopt() racing.

Add READ_ONCE()/WRITE_ONCE() to document races on this lockless field.

syzbot report was:
BUG: KCSAN: data-race in udp_lib_setsockopt / udp_lib_setsockopt

read-write to 0xffff8881083603fa of 1 bytes by task 16557 on cpu 0:
udp_lib_setsockopt+0x682/0x6c0
udp_setsockopt+0x73/0xa0 net/ipv4/udp.c:2779
sock_common_setsockopt+0x61/0x70 net/core/sock.c:3697
__sys_setsockopt+0x1c9/0x230 net/socket.c:2263
__do_sys_setsockopt net/socket.c:2274 [inline]
__se_sys_setsockopt net/socket.c:2271 [inline]
__x64_sys_setsockopt+0x66/0x80 net/socket.c:2271
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read-write to 0xffff8881083603fa of 1 bytes by task 16554 on cpu 1:
udp_lib_setsockopt+0x682/0x6c0
udp_setsockopt+0x73/0xa0 net/ipv4/udp.c:2779
sock_common_setsockopt+0x61/0x70 net/core/sock.c:3697
__sys_setsockopt+0x1c9/0x230 net/socket.c:2263
__do_sys_setsockopt net/socket.c:2274 [inline]
__se_sys_setsockopt net/socket.c:2271 [inline]
__x64_sys_setsockopt+0x66/0x80 net/socket.c:2271
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x01 -> 0x05

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 16554 Comm: syz-executor.5 Not tainted 6.5.0-rc7-syzkaller-00004-gf7757129e3de #0

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Willem de Bruijn 
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

udp: lockless UDP_ENCAP_L2TPINUDP / UDP_GRO

2024-01-10T16:10:28+00:00

[ Upstream commit ac9a7f4ce5dda1472e8f44096f33066c6ec1a3b4 ]

Move udp->encap_enabled to udp->udp_flags.

Add udp_test_and_set_bit() helper to allow lockless
udp_tunnel_encap_enable() implementation.

Signed-off-by: Eric Dumazet 
Reviewed-by: Willem de Bruijn 
Signed-off-by: Paolo Abeni 
Stable-dep-of: 70a36f571362 ("udp: annotate data-races around udp->encap_type")
Signed-off-by: Sasha Levin

udp: move udp->gro_enabled to udp->udp_flags

2024-01-10T16:10:28+00:00

[ Upstream commit e1dc0615c6b08ef36414f08c011965b8fb56198b ]

syzbot reported that udp->gro_enabled can be read locklessly.
Use one atomic bit from udp->udp_flags.

Fixes: e20cf8d3f1f7 ("udp: implement GRO for plain UDP sockets.")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Willem de Bruijn 
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

udp: move udp->no_check6_rx to udp->udp_flags

2024-01-10T16:10:28+00:00

[ Upstream commit bcbc1b1de884647aa0318bf74eb7f293d72a1e40 ]

syzbot reported that udp->no_check6_rx can be read locklessly.
Use one atomic bit from udp->udp_flags.

Fixes: 1c19448c9ba6 ("net: Make enabling of zero UDP6 csums more restrictive")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Willem de Bruijn 
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

udp: move udp->no_check6_tx to udp->udp_flags

2024-01-10T16:10:27+00:00

[ Upstream commit a0002127cd746fcaa182ad3386ef6931c37f3bda ]

syzbot reported that udp->no_check6_tx can be read locklessly.
Use one atomic bit from udp->udp_flags

Fixes: 1c19448c9ba6 ("net: Make enabling of zero UDP6 csums more restrictive")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Willem de Bruijn 
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

udp: introduce udp->udp_flags

2024-01-10T16:10:27+00:00

[ Upstream commit 81b36803ac139827538ac5ce4028e750a3c53f53 ]

According to syzbot, it is time to use proper atomic flags
for various UDP flags.

Add udp_flags field, and convert udp->corkflag to first
bit in it.

Signed-off-by: Eric Dumazet 
Reviewed-by: Willem de Bruijn 
Signed-off-by: Paolo Abeni 
Stable-dep-of: a0002127cd74 ("udp: move udp->no_check6_tx to udp->udp_flags")
Signed-off-by: Sasha Levin

ipv4, ipv6: Use splice_eof() to flush

2024-01-10T16:10:27+00:00

[ Upstream commit 1d7e4538a5463faa0b0e26a7a7b6bd68c7dfdd78 ]

Allow splice to undo the effects of MSG_MORE after prematurely ending a
splice/sendfile due to getting an EOF condition (->splice_read() returned
0) after splice had called sendmsg() with MSG_MORE set when the user didn't
set MSG_MORE.

For UDP, a pending packet will not be emitted if the socket is closed
before it is flushed; with this change, it be flushed by ->splice_eof().

For TCP, it's not clear that MSG_MORE is actually effective.

Suggested-by: Linus Torvalds 
Link: https://lore.kernel.org/r/CAHk-=wh=V579PDYvkpnTobCLGczbgxpMgGmmhqiTyE34Cpi5Gg@mail.gmail.com/
Signed-off-by: David Howells 
cc: Kuniyuki Iwashima 
cc: Willem de Bruijn 
cc: David Ahern 
cc: Jens Axboe 
cc: Matthew Wilcox 
Signed-off-by: Jakub Kicinski 
Stable-dep-of: a0002127cd74 ("udp: move udp->no_check6_tx to udp->udp_flags")
Signed-off-by: Sasha Levin

net: annotate data-races around sk->sk_tsflags

2024-01-10T16:10:23+00:00

[ Upstream commit e3390b30a5dfb112e8e802a59c0f68f947b638b2 ]

sk->sk_tsflags can be read locklessly, add corresponding annotations.

Fixes: b9f40e21ef42 ("net-timestamp: move timestamp flags out of sk_flags")
Signed-off-by: Eric Dumazet 
Cc: Willem de Bruijn 
Signed-off-by: David S. Miller 
Stable-dep-of: 7f6ca95d16b9 ("net: Implement missing getsockopt(SO_TIMESTAMPING_NEW)")
Signed-off-by: Sasha Levin

net-timestamp: extend SOF_TIMESTAMPING_OPT_ID to HW timestamps

2024-01-10T16:10:23+00:00

[ Upstream commit 8ca5a5790b9a1ce147484d2a2c4e66d2553f3d6c ]

When the feature was added it was enabled for SW timestamps only but
with current hardware the same out-of-order timestamps can be seen.
Let's expand the area for the feature to all types of timestamps.

Signed-off-by: Vadim Fedorenko 
Reviewed-by: Willem de Bruijn 
Signed-off-by: David S. Miller 
Stable-dep-of: 7f6ca95d16b9 ("net: Implement missing getsockopt(SO_TIMESTAMPING_NEW)")
Signed-off-by: Sasha Levin