linux-stable.git/net/netfilter/ipvs, branch v6.1.136

ipvs: prevent integer overflow in do_ip_vs_get_ctl()

2025-03-28T20:58:49+00:00

[ Upstream commit 80b78c39eb86e6b55f56363b709eb817527da5aa ]

The get->num_services variable is an unsigned int which is controlled by
the user.  The struct_size() function ensures that the size calculation
does not overflow an unsigned long, however, we are saving the result to
an int so the calculation can overflow.

Both "len" and "get->num_services" come from the user.  This check is
just a sanity check to help the user and ensure they are using the API
correctly.  An integer overflow here is not a big deal.  This has no
security impact.

Save the result from struct_size() type size_t to fix this integer
overflow bug.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Dan Carpenter 
Acked-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: fix UB due to uninitialized stack access in ip_vs_protocol_init()

2024-12-14T18:54:20+00:00

[ Upstream commit 146b6f1112eb30a19776d6c323c994e9d67790db ]

Under certain kernel configurations when building with Clang/LLVM, the
compiler does not generate a return or jump as the terminator
instruction for ip_vs_protocol_init(), triggering the following objtool
warning during build time:

  vmlinux.o: warning: objtool: ip_vs_protocol_init() falls through to next function __initstub__kmod_ip_vs_rr__935_123_ip_vs_rr_init6()

At runtime, this either causes an oops when trying to load the ipvs
module or a boot-time panic if ipvs is built-in. This same issue has
been reported by the Intel kernel test robot previously.

Digging deeper into both LLVM and the kernel code reveals this to be a
undefined behavior problem. ip_vs_protocol_init() uses a on-stack buffer
of 64 chars to store the registered protocol names and leaves it
uninitialized after definition. The function calls strnlen() when
concatenating protocol names into the buffer. With CONFIG_FORTIFY_SOURCE
strnlen() performs an extra step to check whether the last byte of the
input char buffer is a null character (commit 3009f891bb9f ("fortify:
Allow strlen() and strnlen() to pass compile-time known lengths")).
This, together with possibly other configurations, cause the following
IR to be generated:

  define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #5 section ".init.text" align 16 !kcfi_type !29 {
    %1 = alloca [64 x i8], align 16
    ...

  14:                                               ; preds = %11
    %15 = getelementptr inbounds i8, ptr %1, i64 63
    %16 = load i8, ptr %15, align 1
    %17 = tail call i1 @llvm.is.constant.i8(i8 %16)
    %18 = icmp eq i8 %16, 0
    %19 = select i1 %17, i1 %18, i1 false
    br i1 %19, label %20, label %23

  20:                                               ; preds = %14
    %21 = call i64 @strlen(ptr noundef nonnull dereferenceable(1) %1) #23
    ...

  23:                                               ; preds = %14, %11, %20
    %24 = call i64 @strnlen(ptr noundef nonnull dereferenceable(1) %1, i64 noundef 64) #24
    ...
  }

The above code calculates the address of the last char in the buffer
(value %15) and then loads from it (value %16). Because the buffer is
never initialized, the LLVM GVN pass marks value %16 as undefined:

  %13 = getelementptr inbounds i8, ptr %1, i64 63
  br i1 undef, label %14, label %17

This gives later passes (SCCP, in particular) more DCE opportunities by
propagating the undef value further, and eventually removes everything
after the load on the uninitialized stack location:

  define hidden i32 @ip_vs_protocol_init() local_unnamed_addr #0 section ".init.text" align 16 !kcfi_type !11 {
    %1 = alloca [64 x i8], align 16
    ...

  12:                                               ; preds = %11
    %13 = getelementptr inbounds i8, ptr %1, i64 63
    unreachable
  }

In this way, the generated native code will just fall through to the
next function, as LLVM does not generate any code for the unreachable IR
instruction and leaves the function without a terminator.

Zero the on-stack buffer to avoid this possible UB.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: kernel test robot 
Closes: https://lore.kernel.org/oe-kbuild-all/202402100205.PWXIz1ZK-lkp@intel.com/
Co-developed-by: Ruowen Qin 
Signed-off-by: Ruowen Qin 
Signed-off-by: Jinghao Jia 
Acked-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: properly dereference pe in ip_vs_add_service

2024-11-22T14:37:34+00:00

[ Upstream commit cbd070a4ae62f119058973f6d2c984e325bce6e7 ]

Use pe directly to resolve sparse warning:

  net/netfilter/ipvs/ip_vs_ctl.c:1471:27: warning: dereference of noderef expression

Fixes: 39b972231536 ("ipvs: handle connections started by real-servers")
Signed-off-by: Chen Hanxiao 
Acked-by: Julian Anastasov 
Acked-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso 
[ Resolve minor conflicts to fix CVE-2024-42322 ]
Signed-off-by: Bin Lan 
Signed-off-by: Greg Kroah-Hartman

ipvs: Avoid unnecessary calls to skb_is_gso_sctp

2024-08-03T06:49:06+00:00

[ Upstream commit 53796b03295cf7ab1fc8600016fa6dfbf4a494a0 ]

In the context of the SCTP SNAT/DNAT handler, these calls can only
return true.

Fixes: e10d3ba4d434 ("ipvs: Fix checksumming on GSO of SCTP packets")
Signed-off-by: Ismael Luceno 
Acked-by: Julian Anastasov 
Acked-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: Fix checksumming on GSO of SCTP packets

2024-05-02T14:29:25+00:00

[ Upstream commit e10d3ba4d434ed172914617ed8d74bd411421193 ]

It was observed in the wild that pairs of consecutive packets would leave
the IPVS with the same wrong checksum, and the issue only went away when
disabling GSO.

IPVS needs to avoid computing the SCTP checksum when using GSO.

Fixes: 90017accff61 ("sctp: Add GSO support")
Co-developed-by: Firo Yang 
Signed-off-by: Ismael Luceno 
Tested-by: Andreas Taschner 
Acked-by: Julian Anastasov 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

ipvs: avoid stat macros calls from preemptible context

2024-01-25T23:27:51+00:00

[ Upstream commit d6938c1c76c64f42363d0d1f051e1b4641c2ad40 ]

Inside decrement_ttl() upon discovering that the packet ttl has exceeded,
__IP_INC_STATS and __IP6_INC_STATS macros can be called from preemptible
context having the following backtrace:

check_preemption_disabled: 48 callbacks suppressed
BUG: using __this_cpu_add() in preemptible [00000000] code: curl/1177
caller is decrement_ttl+0x217/0x830
CPU: 5 PID: 1177 Comm: curl Not tainted 6.7.0+ #34
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 04/01/2014
Call Trace:
 
 dump_stack_lvl+0xbd/0xe0
 check_preemption_disabled+0xd1/0xe0
 decrement_ttl+0x217/0x830
 __ip_vs_get_out_rt+0x4e0/0x1ef0
 ip_vs_nat_xmit+0x205/0xcd0
 ip_vs_in_hook+0x9b1/0x26a0
 nf_hook_slow+0xc2/0x210
 nf_hook+0x1fb/0x770
 __ip_local_out+0x33b/0x640
 ip_local_out+0x2a/0x490
 __ip_queue_xmit+0x990/0x1d10
 __tcp_transmit_skb+0x288b/0x3d10
 tcp_connect+0x3466/0x5180
 tcp_v4_connect+0x1535/0x1bb0
 __inet_stream_connect+0x40d/0x1040
 inet_stream_connect+0x57/0xa0
 __sys_connect_file+0x162/0x1a0
 __sys_connect+0x137/0x160
 __x64_sys_connect+0x72/0xb0
 do_syscall_64+0x6f/0x140
 entry_SYSCALL_64_after_hwframe+0x6e/0x76
RIP: 0033:0x7fe6dbbc34e0

Use the corresponding preemption-aware variants: IP_INC_STATS and
IP6_INC_STATS.

Found by Linux Verification Center (linuxtesting.org).

Fixes: 8d8e20e2d7bb ("ipvs: Decrement ttl")
Signed-off-by: Fedor Pchelkin 
Acked-by: Julian Anastasov 
Acked-by: Simon Horman 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: use skb_ip_totlen and iph_totlen

2024-01-10T16:10:21+00:00

[ Upstream commit a13fbf5ed5b4fc9095f12e955ca3a59b5507ff01 ]

There are also quite some places in netfilter that may process IPv4 TCP
GSO packets, we need to replace them too.

In length_mt(), we have to use u_int32_t/int to accept skb_ip_totlen()
return value, otherwise it may overflow and mismatch. This change will
also help us add selftest for IPv4 BIG TCP in the following patch.

Note that we don't need to replace the one in tcpmss_tg4(), as it will
return if there is data after tcphdr in tcpmss_mangle_packet(). The
same in mangle_contents() in nf_nat_helper.c, it returns false when
skb->len + extra > 65535 in enlarge_skb().

Signed-off-by: Xin Long 
Reviewed-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski 
Stable-dep-of: 0ae8e4cca787 ("netfilter: nf_tables: set transport offset from mac header for netdev/egress")
Signed-off-by: Sasha Levin

net: prevent address rewrite in kernel_bind()

2023-10-19T21:08:50+00:00

commit c889a99a21bf124c3db08d09df919f0eccc5ea4c upstream.

Similar to the change in commit 0bdf399342c5("net: Avoid address
overwrite in kernel_connect"), BPF hooks run on bind may rewrite the
address passed to kernel_bind(). This change

1) Makes a copy of the bind address in kernel_bind() to insulate
   callers.
2) Replaces direct calls to sock->ops->bind() in net with kernel_bind()

Link: https://lore.kernel.org/netdev/20230912013332.2048422-1-jrife@google.com/
Fixes: 4fbac77d2d09 ("bpf: Hooks for sys_bind")
Cc: stable@vger.kernel.org
Reviewed-by: Willem de Bruijn 
Signed-off-by: Jordan Rife 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: replace calls to sock->ops->connect() with kernel_connect()

2023-10-10T20:00:38+00:00

commit 26297b4ce1ce4ea40bc9a48ec99f45da3f64d2e2 upstream.

commit 0bdf399342c5 ("net: Avoid address overwrite in kernel_connect")
ensured that kernel_connect() will not overwrite the address parameter
in cases where BPF connect hooks perform an address rewrite. This change
replaces direct calls to sock->ops->connect() in net with kernel_connect()
to make these call safe.

Link: https://lore.kernel.org/netdev/20230912013332.2048422-1-jrife@google.com/
Fixes: d74bad4e74ee ("bpf: Hooks for sys_connect")
Cc: stable@vger.kernel.org
Reviewed-by: Willem de Bruijn 
Signed-off-by: Jordan Rife 
Reviewed-by: Simon Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

ipvs: fix racy memcpy in proc_do_sync_threshold

2023-08-23T15:52:34+00:00

[ Upstream commit 5310760af1d4fbea1452bfc77db5f9a680f7ae47 ]

When two threads run proc_do_sync_threshold() in parallel,
data races could happen between the two memcpy():

Thread-1			Thread-2
memcpy(val, valp, sizeof(val));
				memcpy(valp, val, sizeof(val));

This race might mess up the (struct ctl_table *) table->data,
so we add a mutex lock to serialize them.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Link: https://lore.kernel.org/netdev/B6988E90-0A1E-4B85-BF26-2DAF6D482433@gmail.com/
Signed-off-by: Sishuai Gong 
Acked-by: Simon Horman 
Acked-by: Julian Anastasov 
Signed-off-by: Florian Westphal 
Signed-off-by: Sasha Levin