linux-stable.git/net/packet, branch linux-6.5.y

af_packet: Fix fortified memcpy() without flex array.

2023-10-19T21:11:01+00:00

[ Upstream commit e2bca4870fdaf855651ee80b083d892599c5d982 ]

Sergei Trofimovich reported a regression [0] caused by commit a0ade8404c3b
("af_packet: Fix warning of fortified memcpy() in packet_getname().").

It introduced a flex array sll_addr_flex in struct sockaddr_ll as a
union-ed member with sll_addr to work around the fortified memcpy() check.

However, a userspace program uses a struct that has struct sockaddr_ll in
the middle, where a flex array is illegal to exist.

  include/linux/if_packet.h:24:17: error: flexible array member 'sockaddr_ll::::::sll_addr_flex' not at end of 'struct packet_info_t'
     24 |                 __DECLARE_FLEX_ARRAY(unsigned char, sll_addr_flex);
        |                 ^~~~~~~~~~~~~~~~~~~~

To fix the regression, let's go back to the first attempt [1] telling
memcpy() the actual size of the array.

Reported-by: Sergei Trofimovich 
Closes: https://github.com/NixOS/nixpkgs/pull/252587#issuecomment-1741733002 [0]
Link: https://lore.kernel.org/netdev/20230720004410.87588-3-kuniyu@amazon.com/ [1]
Fixes: a0ade8404c3b ("af_packet: Fix warning of fortified memcpy() in packet_getname().")
Signed-off-by: Kuniyuki Iwashima 
Link: https://lore.kernel.org/r/20231009153151.75688-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

net/packet: annotate data-races around tp->status

2023-08-05T01:03:16+00:00

Another syzbot report [1] is about tp->status lockless reads
from __packet_get_status()

[1]
BUG: KCSAN: data-race in __packet_rcv_has_room / __packet_set_status

write to 0xffff888117d7c080 of 8 bytes by interrupt on cpu 0:
__packet_set_status+0x78/0xa0 net/packet/af_packet.c:407
tpacket_rcv+0x18bb/0x1a60 net/packet/af_packet.c:2483
deliver_skb net/core/dev.c:2173 [inline]
__netif_receive_skb_core+0x408/0x1e80 net/core/dev.c:5337
__netif_receive_skb_one_core net/core/dev.c:5491 [inline]
__netif_receive_skb+0x57/0x1b0 net/core/dev.c:5607
process_backlog+0x21f/0x380 net/core/dev.c:5935
__napi_poll+0x60/0x3b0 net/core/dev.c:6498
napi_poll net/core/dev.c:6565 [inline]
net_rx_action+0x32b/0x750 net/core/dev.c:6698
__do_softirq+0xc1/0x265 kernel/softirq.c:571
invoke_softirq kernel/softirq.c:445 [inline]
__irq_exit_rcu+0x57/0xa0 kernel/softirq.c:650
sysvec_apic_timer_interrupt+0x6d/0x80 arch/x86/kernel/apic/apic.c:1106
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:645
smpboot_thread_fn+0x33c/0x4a0 kernel/smpboot.c:112
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

read to 0xffff888117d7c080 of 8 bytes by interrupt on cpu 1:
__packet_get_status net/packet/af_packet.c:436 [inline]
packet_lookup_frame net/packet/af_packet.c:524 [inline]
__tpacket_has_room net/packet/af_packet.c:1255 [inline]
__packet_rcv_has_room+0x3f9/0x450 net/packet/af_packet.c:1298
tpacket_rcv+0x275/0x1a60 net/packet/af_packet.c:2285
deliver_skb net/core/dev.c:2173 [inline]
dev_queue_xmit_nit+0x38a/0x5e0 net/core/dev.c:2243
xmit_one net/core/dev.c:3574 [inline]
dev_hard_start_xmit+0xcf/0x3f0 net/core/dev.c:3594
__dev_queue_xmit+0xefb/0x1d10 net/core/dev.c:4244
dev_queue_xmit include/linux/netdevice.h:3088 [inline]
can_send+0x4eb/0x5d0 net/can/af_can.c:276
bcm_can_tx+0x314/0x410 net/can/bcm.c:302
bcm_tx_timeout_handler+0xdb/0x260
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x217/0x700 kernel/time/hrtimer.c:1749
hrtimer_run_softirq+0xd6/0x120 kernel/time/hrtimer.c:1766
__do_softirq+0xc1/0x265 kernel/softirq.c:571
run_ksoftirqd+0x17/0x20 kernel/softirq.c:939
smpboot_thread_fn+0x30a/0x4a0 kernel/smpboot.c:164
kthread+0x1d7/0x210 kernel/kthread.c:379
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308

value changed: 0x0000000000000000 -> 0x0000000020000081

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 19 Comm: ksoftirqd/1 Not tainted 6.4.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023

Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Willem de Bruijn 
Link: https://lore.kernel.org/r/20230803145600.2937518-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: annotate data-races around sk->sk_priority

2023-07-29T17:13:41+00:00

sk_getsockopt() runs locklessly. This means sk->sk_priority
can be read while other threads are changing its value.

Other reads also happen without socket lock being held.

Add missing annotations where needed.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: annotate data-races around sk->sk_mark

2023-07-29T17:13:41+00:00

sk->sk_mark is often read while another thread could change the value.

Fixes: 4a19ec5800fc ("[NET]: Introducing socket mark socket option.")
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

af_packet: Fix warning of fortified memcpy() in packet_getname().

2023-07-26T03:10:05+00:00

syzkaller found a warning in packet_getname() [0], where we try to
copy 16 bytes to sockaddr_ll.sll_addr[8].

Some devices (ip6gre, vti6, ip6tnl) have 16 bytes address expressed
by struct in6_addr.  Also, Infiniband has 32 bytes as MAX_ADDR_LEN.

The write seems to overflow, but actually not since we use struct
sockaddr_storage defined in __sys_getsockname() and its size is 128
(_K_SS_MAXSIZE) bytes.  Thus, we have sufficient room after sll_addr[]
as __data[].

To avoid the warning, let's add a flex array member union-ed with
sll_addr.

Another option would be to use strncpy() and limit the copied length
to sizeof(sll_addr), but it will return the partial address and break
an application that passes sockaddr_storage to getsockname().

[0]:
memcpy: detected field-spanning write (size 16) of single field "sll->sll_addr" at net/packet/af_packet.c:3604 (size 8)
WARNING: CPU: 0 PID: 255 at net/packet/af_packet.c:3604 packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
Modules linked in:
CPU: 0 PID: 255 Comm: syz-executor750 Not tainted 6.5.0-rc1-00330-g60cc1f7d0605 #4
Hardware name: linux,dummy-virt (DT)
pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
lr : packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
sp : ffff800089887bc0
x29: ffff800089887bc0 x28: ffff000010f80f80 x27: 0000000000000003
x26: dfff800000000000 x25: ffff700011310f80 x24: ffff800087d55000
x23: dfff800000000000 x22: ffff800089887c2c x21: 0000000000000010
x20: ffff00000de08310 x19: ffff800089887c20 x18: ffff800086ab1630
x17: 20646c6569662065 x16: 6c676e697320666f x15: 0000000000000001
x14: 1fffe0000d56d7ca x13: 0000000000000000 x12: 0000000000000000
x11: 0000000000000000 x10: 0000000000000000 x9 : 3e60944c3da92b00
x8 : 3e60944c3da92b00 x7 : 0000000000000001 x6 : 0000000000000001
x5 : ffff8000898874f8 x4 : ffff800086ac99e0 x3 : ffff8000803f8808
x2 : 0000000000000001 x1 : 0000000100000000 x0 : 0000000000000000
Call trace:
 packet_getname+0x25c/0x3a0 net/packet/af_packet.c:3604
 __sys_getsockname+0x168/0x24c net/socket.c:2042
 __do_sys_getsockname net/socket.c:2057 [inline]
 __se_sys_getsockname net/socket.c:2054 [inline]
 __arm64_sys_getsockname+0x7c/0x94 net/socket.c:2054
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x2c0 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x134/0x240 arch/arm64/kernel/syscall.c:139
 do_el0_svc+0x64/0x198 arch/arm64/kernel/syscall.c:188
 el0_svc+0x2c/0x7c arch/arm64/kernel/entry-common.c:647
 el0t_64_sync_handler+0x84/0xfc arch/arm64/kernel/entry-common.c:665
 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:591

Fixes: df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3")
Reported-by: syzkaller 
Suggested-by: Kees Cook 
Signed-off-by: Kuniyuki Iwashima 
Link: https://lore.kernel.org/r/20230724213425.22920-3-kuniyu@amazon.com
Reviewed-by: Simon Horman 
Reviewed-by: Kees Cook 
Signed-off-by: Jakub Kicinski

sock: Remove ->sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)

2023-06-24T22:50:13+00:00

Remove ->sendpage() and ->sendpage_locked().  sendmsg() with
MSG_SPLICE_PAGES should be used instead.  This allows multiple pages and
multipage folios to be passed through.

Signed-off-by: David Howells 
Acked-by: Marc Kleine-Budde  # for net/can
cc: Jens Axboe 
cc: Matthew Wilcox 
cc: linux-afs@lists.infradead.org
cc: mptcp@lists.linux.dev
cc: rds-devel@oss.oracle.com
cc: tipc-discussion@lists.sourceforge.net
cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com
Signed-off-by: Jakub Kicinski

af_packet: do not use READ_ONCE() in packet_bind()

2023-05-30T05:03:48+00:00

A recent patch added READ_ONCE() in packet_bind() and packet_bind_spkt()

This is better handled by reading pkt_sk(sk)->num later
in packet_do_bind() while appropriate lock is held.

READ_ONCE() in writers are often an evidence of something being wrong.

Fixes: 822b5a1c17df ("af_packet: Fix data-races of pkt_sk(sk)->num.")
Signed-off-by: Eric Dumazet 
Reviewed-by: Willem de Bruijn 
Reviewed-by: Jiri Pirko 
Reviewed-by: Kuniyuki Iwashima 
Link: https://lore.kernel.org/r/20230526154342.2533026-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

af_packet: Fix data-races of pkt_sk(sk)->num.

2023-05-26T04:03:23+00:00

syzkaller found a data race of pkt_sk(sk)->num.

The value is changed under lock_sock() and po->bind_lock, so we
need READ_ONCE() to access pkt_sk(sk)->num without these locks in
packet_bind_spkt(), packet_bind(), and sk_diag_fill().

Note that WRITE_ONCE() is already added by commit c7d2ef5dd4b0
("net/packet: annotate accesses to po->bind").

BUG: KCSAN: data-race in packet_bind / packet_do_bind

write (marked) to 0xffff88802ffd1cee of 2 bytes by task 7322 on cpu 0:
 packet_do_bind+0x446/0x640 net/packet/af_packet.c:3236
 packet_bind+0x99/0xe0 net/packet/af_packet.c:3321
 __sys_bind+0x19b/0x1e0 net/socket.c:1803
 __do_sys_bind net/socket.c:1814 [inline]
 __se_sys_bind net/socket.c:1812 [inline]
 __x64_sys_bind+0x40/0x50 net/socket.c:1812
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

read to 0xffff88802ffd1cee of 2 bytes by task 7318 on cpu 1:
 packet_bind+0xbf/0xe0 net/packet/af_packet.c:3322
 __sys_bind+0x19b/0x1e0 net/socket.c:1803
 __do_sys_bind net/socket.c:1814 [inline]
 __se_sys_bind net/socket.c:1812 [inline]
 __x64_sys_bind+0x40/0x50 net/socket.c:1812
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc

value changed: 0x0300 -> 0x0000

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 7318 Comm: syz-executor.4 Not tainted 6.3.0-13380-g7fddb5b5300c #4
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

Fixes: 96ec6327144e ("packet: Diag core and basic socket info dumping")
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzkaller 
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Willem de Bruijn 
Link: https://lore.kernel.org/r/20230524232934.50950-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski

net: add vlan_get_protocol_and_depth() helper

2023-05-10T09:25:55+00:00

Before blamed commit, pskb_may_pull() was used instead
of skb_header_pointer() in __vlan_get_protocol() and friends.

Few callers depended on skb->head being populated with MAC header,
syzbot caught one of them (skb_mac_gso_segment())

Add vlan_get_protocol_and_depth() to make the intent clearer
and use it where sensible.

This is a more generic fix than commit e9d3f80935b6
("net/af_packet: make sure to pull mac header") which was
dealing with a similar issue.

kernel BUG at include/linux/skbuff.h:2655 !
invalid opcode: 0000 [#1] SMP KASAN
CPU: 0 PID: 1441 Comm: syz-executor199 Not tainted 6.1.24-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
RIP: 0010:__skb_pull include/linux/skbuff.h:2655 [inline]
RIP: 0010:skb_mac_gso_segment+0x68f/0x6a0 net/core/gro.c:136
Code: fd 48 8b 5c 24 10 44 89 6b 70 48 c7 c7 c0 ae 0d 86 44 89 e6 e8 a1 91 d0 00 48 c7 c7 00 af 0d 86 48 89 de 31 d2 e8 d1 4a e9 ff <0f> 0b 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 41
RSP: 0018:ffffc90001bd7520 EFLAGS: 00010286
RAX: ffffffff8469736a RBX: ffff88810f31dac0 RCX: ffff888115a18b00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90001bd75e8 R08: ffffffff84697183 R09: fffff5200037adf9
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000012
R13: 000000000000fee5 R14: 0000000000005865 R15: 000000000000fed7
FS: 000055555633f300(0000) GS:ffff8881f6a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 0000000116fea000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

[] __skb_gso_segment+0x32d/0x4c0 net/core/dev.c:3419
[] skb_gso_segment include/linux/netdevice.h:4819 [inline]
[] validate_xmit_skb+0x3aa/0xee0 net/core/dev.c:3725
[] __dev_queue_xmit+0x1332/0x3300 net/core/dev.c:4313
[] dev_queue_xmit+0x17/0x20 include/linux/netdevice.h:3029
[] packet_snd net/packet/af_packet.c:3111 [inline]
[] packet_sendmsg+0x49d2/0x6470 net/packet/af_packet.c:3142
[] sock_sendmsg_nosec net/socket.c:716 [inline]
[] sock_sendmsg net/socket.c:736 [inline]
[] __sys_sendto+0x472/0x5f0 net/socket.c:2139
[] __do_sys_sendto net/socket.c:2151 [inline]
[] __se_sys_sendto net/socket.c:2147 [inline]
[] __x64_sys_sendto+0xe5/0x100 net/socket.c:2147
[] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[] do_syscall_64+0x2f/0x50 arch/x86/entry/common.c:80
[] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 469aceddfa3e ("vlan: consolidate VLAN parsing code and limit max parsing depth")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Cc: Toke Høiland-Jørgensen 
Cc: Willem de Bruijn 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller

af_packet: Don't send zero-byte data in packet_sendmsg_spkt().

2023-05-03T08:20:18+00:00

syzkaller reported a warning below [0].

We can reproduce it by sending 0-byte data from the (AF_PACKET,
SOCK_PACKET) socket via some devices whose dev->hard_header_len
is 0.

    struct sockaddr_pkt addr = {
        .spkt_family = AF_PACKET,
        .spkt_device = "tun0",
    };
    int fd;

    fd = socket(AF_PACKET, SOCK_PACKET, 0);
    sendto(fd, NULL, 0, 0, (struct sockaddr *)&addr, sizeof(addr));

We have a similar fix for the (AF_PACKET, SOCK_RAW) socket as
commit dc633700f00f ("net/af_packet: check len when min_header_len
equals to 0").

Let's add the same test for the SOCK_PACKET socket.

[0]:
skb_assert_len
WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 skb_assert_len include/linux/skbuff.h:2552 [inline]
WARNING: CPU: 1 PID: 19945 at include/linux/skbuff.h:2552 __dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159
Modules linked in:
CPU: 1 PID: 19945 Comm: syz-executor.0 Not tainted 6.3.0-rc7-02330-gca6270c12e20 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014
RIP: 0010:skb_assert_len include/linux/skbuff.h:2552 [inline]
RIP: 0010:__dev_queue_xmit+0x1f26/0x31d0 net/core/dev.c:4159
Code: 89 de e8 1d a2 85 fd 84 db 75 21 e8 64 a9 85 fd 48 c7 c6 80 2a 1f 86 48 c7 c7 c0 06 1f 86 c6 05 23 cf 27 04 01 e8 fa ee 56 fd <0f> 0b e8 43 a9 85 fd 0f b6 1d 0f cf 27 04 31 ff 89 de e8 e3 a1 85
RSP: 0018:ffff8880217af6e0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffc90001133000
RDX: 0000000000040000 RSI: ffffffff81186922 RDI: 0000000000000001
RBP: ffff8880217af8b0 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888030045640
R13: ffff8880300456b0 R14: ffff888030045650 R15: ffff888030045718
FS:  00007fc5864da640(0000) GS:ffff88806cd00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020005740 CR3: 000000003f856003 CR4: 0000000000770ee0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
PKRU: 55555554
Call Trace:
 
 dev_queue_xmit include/linux/netdevice.h:3085 [inline]
 packet_sendmsg_spkt+0xc4b/0x1230 net/packet/af_packet.c:2066
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0x1b4/0x200 net/socket.c:747
 ____sys_sendmsg+0x331/0x970 net/socket.c:2503
 ___sys_sendmsg+0x11d/0x1c0 net/socket.c:2557
 __sys_sendmmsg+0x18c/0x430 net/socket.c:2643
 __do_sys_sendmmsg net/socket.c:2672 [inline]
 __se_sys_sendmmsg net/socket.c:2669 [inline]
 __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2669
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3c/0x90 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x72/0xdc
RIP: 0033:0x7fc58791de5d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 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 8b 0d 73 9f 1b 00 f7 d8 64 89 01 48
RSP: 002b:00007fc5864d9cc8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00000000004bbf80 RCX: 00007fc58791de5d
RDX: 0000000000000001 RSI: 0000000020005740 RDI: 0000000000000004
RBP: 00000000004bbf80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fc58797e530 R15: 0000000000000000
 
---[ end trace 0000000000000000 ]---
skb len=0 headroom=16 headlen=0 tailroom=304
mac=(16,0) net=(16,-1) trans=-1
shinfo(txflags=0 nr_frags=0 gso(size=0 type=0 segs=0))
csum(0x0 ip_summed=0 complete_sw=0 valid=0 level=0)
hash(0x0 sw=0 l4=0) proto=0x0000 pkttype=0 iif=0
dev name=sit0 feat=0x00000006401d7869
sk family=17 type=10 proto=0

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot 
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Willem de Bruijn 
Signed-off-by: David S. Miller