Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Marcelo Ricardo Leitner]

On Tue, Aug 15, 2017 at 08:37:49AM -0700, Eric Dumazet wrote:
> On Tue, 2017-08-15 at 12:05 -0300, Marcelo Ricardo Leitner wrote:
> 
> > Ok, but I should see a difference in the generated code, right?
> 
> Depends on the compiler. Have you tried older versions ?
> 

This was with gcc 6.4.1, fc25 standard. Only tested with it and didn't
check clang either.

> One argument is that following struct member definition eases code
> review.
> 
> (It is easier to catch a field init is missing)

And a good one, yes.

Thanks,
Marcelo

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Marcelo Ricardo Leitner]

On Tue, Aug 15, 2017 at 08:37:49AM -0700, Eric Dumazet wrote:
> On Tue, 2017-08-15 at 12:05 -0300, Marcelo Ricardo Leitner wrote:
> 
> > Ok, but I should see a difference in the generated code, right?
> 
> Depends on the compiler. Have you tried older versions ?
> 

This was with gcc 6.4.1, fc25 standard. Only tested with it and didn't
check clang either.

> One argument is that following struct member definition eases code
> review.
> 
> (It is easier to catch a field init is missing)

And a good one, yes.

Thanks,
Marcelo

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Eric Dumazet]

On Tue, 2017-08-15 at 12:05 -0300, Marcelo Ricardo Leitner wrote:

> Ok, but I should see a difference in the generated code, right?

Depends on the compiler. Have you tried older versions ?

One argument is that following struct member definition eases code
review.

(It is easier to catch a field init is missing)

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Eric Dumazet]

On Tue, 2017-08-15 at 12:05 -0300, Marcelo Ricardo Leitner wrote:

> Ok, but I should see a difference in the generated code, right?

Depends on the compiler. Have you tried older versions ?

One argument is that following struct member definition eases code
review.

(It is easier to catch a field init is missing)

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Marcelo Ricardo Leitner]

On Mon, Aug 14, 2017 at 07:40:51PM -0700, David Miller wrote:
> From: Marcelo Ricardo Leitner 
> Date: Mon, 14 Aug 2017 22:58:14 -0300
>
> > On Tue, Aug 15, 2017 at 10:43:59AM +0900, 吉藤英明 wrote:
> >> > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> >> > index 2a186b201ad2..a15d691829c6 100644
> >> > --- a/net/sctp/ipv6.c
> >> > +++ b/net/sctp/ipv6.c
> >> > @@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr *addr, 
> >> > struct in6_addr *saddr,
> >> > addr->sa.sa_family = AF_INET6;
> >> > addr->v6.sin6_port = port;
> >> > addr->v6.sin6_addr = *saddr;
> >> > +   addr->v6.sin6_flowinfo = 0;
> >> > +   addr->v6.sin6_scope_id = 0;
> >>
> >> Please set flowinfo between port and addr.
> >
> > Why?
>
> Store buffer compression.
>
> You want to always initialize structure member in the order
> they are in memory.

Thanks.

>
> No, the compiler won't do this automatically.

Ok, but I should see a difference in the generated code, right?

union sctp_addr is a union of sockaddr_in structs, for easy reference
ipv6 being:
struct sockaddr_in6 {
short unsigned int sin6_family;  /* 0 2 */
__be16 sin6_port;/* 2 2 */
__be32 sin6_flowinfo;/* 4 4 */
struct in6_addrsin6_addr;/* 816 */
__u32  sin6_scope_id;/*24 4 */

Current code:
12a1:   ba 0a 00 00 00  mov$0xa,%edx
12a6:   49 8b 5f 68 mov0x68(%r15),%rbx
12aa:   66 89 55 a0 mov%dx,-0x60(%rbp)
 union/struct start -^
12ae:   4d 8d 4f 68 lea0x68(%r15),%r9
12b2:   49 8b 55 40 mov0x40(%r13),%rdx
12b6:   66 c1 c0 08 rol$0x8,%ax(htons)
12ba:   4c 39 cbcmp%r9,%rbx
12bd:   48 89 55 b0 mov%rdx,-0x50(%rbp)
 thus this ---^
12c1:   66 89 45 a2 mov%ax,-0x5e(%rbp)
 ^ port number
12c5:   49 8b 45 38 mov0x38(%r13),%rax
12c9:   48 89 45 a8 mov%rax,-0x58(%rbp)
  and this are the ipv6 addr bytes ---^
12cd:   74 30   je 12ff 

Alexander's:
12a1:   ba 0a 00 00 00  mov$0xa,%edx
12a6:   49 8b 5f 68 mov0x68(%r15),%rbx
12aa:   66 89 55 a0 mov%dx,-0x60(%rbp)
12ae:   4d 8d 4f 68 lea0x68(%r15),%r9
12b2:   49 8b 55 40 mov0x40(%r13),%rdx
12b6:   c7 45 a4 00 00 00 00movl   $0x0,-0x5c(%rbp)
12bd:   c7 45 b8 00 00 00 00movl   $0x0,-0x48(%rbp)
12c4:   66 c1 c0 08 rol$0x8,%ax
12c8:   4c 39 cbcmp%r9,%rbx
12cb:   48 89 55 b0 mov%rdx,-0x50(%rbp)
12cf:   66 89 45 a2 mov%ax,-0x5e(%rbp)
12d3:   49 8b 45 38 mov0x38(%r13),%rax
12d7:   48 89 45 a8 mov%rax,-0x58(%rbp)
12db:   74 30   je 130d 

Hideaki's:
12a1:   ba 0a 00 00 00  mov$0xa,%edx
12a6:   49 8b 5f 68 mov0x68(%r15),%rbx
12aa:   66 89 55 a0 mov%dx,-0x60(%rbp)
12ae:   4d 8d 4f 68 lea0x68(%r15),%r9
12b2:   49 8b 55 40 mov0x40(%r13),%rdx
12b6:   c7 45 a4 00 00 00 00movl   $0x0,-0x5c(%rbp)
12bd:   c7 45 b8 00 00 00 00movl   $0x0,-0x48(%rbp)
12c4:   66 c1 c0 08 rol$0x8,%ax
12c8:   4c 39 cbcmp%r9,%rbx
12cb:   48 89 55 b0 mov%rdx,-0x50(%rbp)
12cf:   66 89 45 a2 mov%ax,-0x5e(%rbp)
12d3:   49 8b 45 38 mov0x38(%r13),%rax
12d7:   48 89 45 a8 mov%rax,-0x58(%rbp)
12db:   74 30   je 130d 

They are the same, and messed up by the compiler breaking the copy of
the ipv6 addr (which was copied backwards) with the port number copy.

  Marcelo

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Marcelo Ricardo Leitner]

On Mon, Aug 14, 2017 at 07:40:51PM -0700, David Miller wrote:
> From: Marcelo Ricardo Leitner 
> Date: Mon, 14 Aug 2017 22:58:14 -0300
>
> > On Tue, Aug 15, 2017 at 10:43:59AM +0900, 吉藤英明 wrote:
> >> > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> >> > index 2a186b201ad2..a15d691829c6 100644
> >> > --- a/net/sctp/ipv6.c
> >> > +++ b/net/sctp/ipv6.c
> >> > @@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr *addr, 
> >> > struct in6_addr *saddr,
> >> > addr->sa.sa_family = AF_INET6;
> >> > addr->v6.sin6_port = port;
> >> > addr->v6.sin6_addr = *saddr;
> >> > +   addr->v6.sin6_flowinfo = 0;
> >> > +   addr->v6.sin6_scope_id = 0;
> >>
> >> Please set flowinfo between port and addr.
> >
> > Why?
>
> Store buffer compression.
>
> You want to always initialize structure member in the order
> they are in memory.

Thanks.

>
> No, the compiler won't do this automatically.

Ok, but I should see a difference in the generated code, right?

union sctp_addr is a union of sockaddr_in structs, for easy reference
ipv6 being:
struct sockaddr_in6 {
short unsigned int sin6_family;  /* 0 2 */
__be16 sin6_port;/* 2 2 */
__be32 sin6_flowinfo;/* 4 4 */
struct in6_addrsin6_addr;/* 816 */
__u32  sin6_scope_id;/*24 4 */

Current code:
12a1:   ba 0a 00 00 00  mov$0xa,%edx
12a6:   49 8b 5f 68 mov0x68(%r15),%rbx
12aa:   66 89 55 a0 mov%dx,-0x60(%rbp)
 union/struct start -^
12ae:   4d 8d 4f 68 lea0x68(%r15),%r9
12b2:   49 8b 55 40 mov0x40(%r13),%rdx
12b6:   66 c1 c0 08 rol$0x8,%ax(htons)
12ba:   4c 39 cbcmp%r9,%rbx
12bd:   48 89 55 b0 mov%rdx,-0x50(%rbp)
 thus this ---^
12c1:   66 89 45 a2 mov%ax,-0x5e(%rbp)
 ^ port number
12c5:   49 8b 45 38 mov0x38(%r13),%rax
12c9:   48 89 45 a8 mov%rax,-0x58(%rbp)
  and this are the ipv6 addr bytes ---^
12cd:   74 30   je 12ff 

Alexander's:
12a1:   ba 0a 00 00 00  mov$0xa,%edx
12a6:   49 8b 5f 68 mov0x68(%r15),%rbx
12aa:   66 89 55 a0 mov%dx,-0x60(%rbp)
12ae:   4d 8d 4f 68 lea0x68(%r15),%r9
12b2:   49 8b 55 40 mov0x40(%r13),%rdx
12b6:   c7 45 a4 00 00 00 00movl   $0x0,-0x5c(%rbp)
12bd:   c7 45 b8 00 00 00 00movl   $0x0,-0x48(%rbp)
12c4:   66 c1 c0 08 rol$0x8,%ax
12c8:   4c 39 cbcmp%r9,%rbx
12cb:   48 89 55 b0 mov%rdx,-0x50(%rbp)
12cf:   66 89 45 a2 mov%ax,-0x5e(%rbp)
12d3:   49 8b 45 38 mov0x38(%r13),%rax
12d7:   48 89 45 a8 mov%rax,-0x58(%rbp)
12db:   74 30   je 130d 

Hideaki's:
12a1:   ba 0a 00 00 00  mov$0xa,%edx
12a6:   49 8b 5f 68 mov0x68(%r15),%rbx
12aa:   66 89 55 a0 mov%dx,-0x60(%rbp)
12ae:   4d 8d 4f 68 lea0x68(%r15),%r9
12b2:   49 8b 55 40 mov0x40(%r13),%rdx
12b6:   c7 45 a4 00 00 00 00movl   $0x0,-0x5c(%rbp)
12bd:   c7 45 b8 00 00 00 00movl   $0x0,-0x48(%rbp)
12c4:   66 c1 c0 08 rol$0x8,%ax
12c8:   4c 39 cbcmp%r9,%rbx
12cb:   48 89 55 b0 mov%rdx,-0x50(%rbp)
12cf:   66 89 45 a2 mov%ax,-0x5e(%rbp)
12d3:   49 8b 45 38 mov0x38(%r13),%rax
12d7:   48 89 45 a8 mov%rax,-0x58(%rbp)
12db:   74 30   je 130d 

They are the same, and messed up by the compiler breaking the copy of
the ipv6 addr (which was copied backwards) with the port number copy.

  Marcelo

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[David Miller]

From: Marcelo Ricardo Leitner 
Date: Mon, 14 Aug 2017 22:58:14 -0300

> On Tue, Aug 15, 2017 at 10:43:59AM +0900, 吉藤英明 wrote:
>> > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
>> > index 2a186b201ad2..a15d691829c6 100644
>> > --- a/net/sctp/ipv6.c
>> > +++ b/net/sctp/ipv6.c
>> > @@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr *addr, 
>> > struct in6_addr *saddr,
>> > addr->sa.sa_family = AF_INET6;
>> > addr->v6.sin6_port = port;
>> > addr->v6.sin6_addr = *saddr;
>> > +   addr->v6.sin6_flowinfo = 0;
>> > +   addr->v6.sin6_scope_id = 0;
>> 
>> Please set flowinfo between port and addr.
> 
> Why?

Store buffer compression.

You want to always initialize structure member in the order
they are in memory.

No, the compiler won't do this automatically.

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[David Miller]

From: Marcelo Ricardo Leitner 
Date: Mon, 14 Aug 2017 22:58:14 -0300

> On Tue, Aug 15, 2017 at 10:43:59AM +0900, 吉藤英明 wrote:
>> > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
>> > index 2a186b201ad2..a15d691829c6 100644
>> > --- a/net/sctp/ipv6.c
>> > +++ b/net/sctp/ipv6.c
>> > @@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr *addr, 
>> > struct in6_addr *saddr,
>> > addr->sa.sa_family = AF_INET6;
>> > addr->v6.sin6_port = port;
>> > addr->v6.sin6_addr = *saddr;
>> > +   addr->v6.sin6_flowinfo = 0;
>> > +   addr->v6.sin6_scope_id = 0;
>> 
>> Please set flowinfo between port and addr.
> 
> Why?

Store buffer compression.

You want to always initialize structure member in the order
they are in memory.

No, the compiler won't do this automatically.

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Marcelo Ricardo Leitner]

On Tue, Aug 15, 2017 at 10:43:59AM +0900, 吉藤英明 wrote:
> Hi,
> 
> 2017-08-15 3:43 GMT+09:00 Alexander Potapenko :
> > KMSAN reported use of uninitialized sctp_addr->v4.sin_addr.s_addr and
> > sctp_addr->v6.sin6_scope_id in sctp_v6_cmp_addr() (see below).
> > Make sure all fields of an IPv6 address are initialized, which
> > guarantees that the IPv4 fields are also initialized.
> >
> > ==
> >  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
> >  net/sctp/ipv6.c:517
> >  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
> >  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
> >  01/01/2011
> >  Call Trace:
> >   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
> >   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
> >   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
> >   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
> >   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
> >   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
> >   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
> >   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
> >   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
> >   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> >   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
> >   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
> >   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
> >   sock_sendmsg_nosec net/socket.c:633 [inline]
> >   sock_sendmsg net/socket.c:643 [inline]
> >   SYSC_sendto+0x608/0x710 net/socket.c:1696
> >   SyS_sendto+0x8a/0xb0 net/socket.c:1664
> >   entry_SYSCALL_64_fastpath+0x13/0x94
> >  RIP: 0033:0x44b479
> >  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
> >  RAX: ffda RBX: 2000 RCX: 0044b479
> >  RDX: 0041 RSI: 20edd000 RDI: 0006
> >  RBP: 007080a8 R08: 20b85fe4 R09: 001c
> >  R10: 00040005 R11: 0286 R12: 
> >  R13: 3760 R14: 006e5820 R15: 00ff8000
> >  origin description: dst_saddr@sctp_v6_get_dst
> >  local variable created at:
> >   sk_fullsock include/net/sock.h:2321 [inline]
> >   inet6_sk include/linux/ipv6.h:309 [inline]
> >   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
> >   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> > ==
> >  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
> >  net/sctp/ipv6.c:517
> >  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
> >  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
> >  01/01/2011
> >  Call Trace:
> >   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
> >   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
> >   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
> >   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
> >   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
> >   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
> >   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
> >   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
> >   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
> >   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> >   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
> >   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
> >   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
> >   sock_sendmsg_nosec net/socket.c:633 [inline]
> >   sock_sendmsg net/socket.c:643 [inline]
> >   SYSC_sendto+0x608/0x710 net/socket.c:1696
> >   SyS_sendto+0x8a/0xb0 net/socket.c:1664
> >   entry_SYSCALL_64_fastpath+0x13/0x94
> >  RIP: 0033:0x44b479
> >  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
> >  RAX: ffda RBX: 2000 RCX: 0044b479
> >  RDX: 0041 RSI: 20edd000 RDI: 0006
> >  RBP: 007080a8 R08: 20b85fe4 R09: 001c
> >  R10: 00040005 R11: 0286 R12: 
> >  R13: 3760 R14: 006e5820 R15: 00ff8000
> >  origin description: dst_saddr@sctp_v6_get_dst
> >  local variable created at:
> >   sk_fullsock include/net/sock.h:2321 [inline]
> >   inet6_sk include/linux/ipv6.h:309 [inline]
> >   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
> >   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> > ==
> >
> > Signed-off-by: Alexander Potapenko 
> > Reviewed-by: Xin Long 
> > ---
> > v2 is identical to v1, resending per request by Marcelo Ricardo Leitner.
> > ---
> >  net/sctp/ipv6.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git 

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Marcelo Ricardo Leitner]

On Tue, Aug 15, 2017 at 10:43:59AM +0900, 吉藤英明 wrote:
> Hi,
> 
> 2017-08-15 3:43 GMT+09:00 Alexander Potapenko :
> > KMSAN reported use of uninitialized sctp_addr->v4.sin_addr.s_addr and
> > sctp_addr->v6.sin6_scope_id in sctp_v6_cmp_addr() (see below).
> > Make sure all fields of an IPv6 address are initialized, which
> > guarantees that the IPv4 fields are also initialized.
> >
> > ==
> >  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
> >  net/sctp/ipv6.c:517
> >  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
> >  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
> >  01/01/2011
> >  Call Trace:
> >   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
> >   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
> >   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
> >   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
> >   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
> >   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
> >   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
> >   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
> >   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
> >   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> >   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
> >   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
> >   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
> >   sock_sendmsg_nosec net/socket.c:633 [inline]
> >   sock_sendmsg net/socket.c:643 [inline]
> >   SYSC_sendto+0x608/0x710 net/socket.c:1696
> >   SyS_sendto+0x8a/0xb0 net/socket.c:1664
> >   entry_SYSCALL_64_fastpath+0x13/0x94
> >  RIP: 0033:0x44b479
> >  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
> >  RAX: ffda RBX: 2000 RCX: 0044b479
> >  RDX: 0041 RSI: 20edd000 RDI: 0006
> >  RBP: 007080a8 R08: 20b85fe4 R09: 001c
> >  R10: 00040005 R11: 0286 R12: 
> >  R13: 3760 R14: 006e5820 R15: 00ff8000
> >  origin description: dst_saddr@sctp_v6_get_dst
> >  local variable created at:
> >   sk_fullsock include/net/sock.h:2321 [inline]
> >   inet6_sk include/linux/ipv6.h:309 [inline]
> >   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
> >   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> > ==
> >  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
> >  net/sctp/ipv6.c:517
> >  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
> >  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
> >  01/01/2011
> >  Call Trace:
> >   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
> >   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
> >   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
> >   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
> >   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
> >   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
> >   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
> >   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
> >   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
> >   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> >   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
> >   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
> >   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
> >   sock_sendmsg_nosec net/socket.c:633 [inline]
> >   sock_sendmsg net/socket.c:643 [inline]
> >   SYSC_sendto+0x608/0x710 net/socket.c:1696
> >   SyS_sendto+0x8a/0xb0 net/socket.c:1664
> >   entry_SYSCALL_64_fastpath+0x13/0x94
> >  RIP: 0033:0x44b479
> >  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
> >  RAX: ffda RBX: 2000 RCX: 0044b479
> >  RDX: 0041 RSI: 20edd000 RDI: 0006
> >  RBP: 007080a8 R08: 20b85fe4 R09: 001c
> >  R10: 00040005 R11: 0286 R12: 
> >  R13: 3760 R14: 006e5820 R15: 00ff8000
> >  origin description: dst_saddr@sctp_v6_get_dst
> >  local variable created at:
> >   sk_fullsock include/net/sock.h:2321 [inline]
> >   inet6_sk include/linux/ipv6.h:309 [inline]
> >   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
> >   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> > ==
> >
> > Signed-off-by: Alexander Potapenko 
> > Reviewed-by: Xin Long 
> > ---
> > v2 is identical to v1, resending per request by Marcelo Ricardo Leitner.
> > ---
> >  net/sctp/ipv6.c | 2 ++
> >  1 file changed, 2 insertions(+)
> >
> > diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> > index 2a186b201ad2..a15d691829c6 

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[吉藤英明]

Hi,

2017-08-15 3:43 GMT+09:00 Alexander Potapenko :
> KMSAN reported use of uninitialized sctp_addr->v4.sin_addr.s_addr and
> sctp_addr->v6.sin6_scope_id in sctp_v6_cmp_addr() (see below).
> Make sure all fields of an IPv6 address are initialized, which
> guarantees that the IPv4 fields are also initialized.
>
> ==
>  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
>  net/sctp/ipv6.c:517
>  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
>  01/01/2011
>  Call Trace:
>   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
>   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
>   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
>   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
>   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
>   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
>   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
>   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
>   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
>   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
>   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
>   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
>   sock_sendmsg_nosec net/socket.c:633 [inline]
>   sock_sendmsg net/socket.c:643 [inline]
>   SYSC_sendto+0x608/0x710 net/socket.c:1696
>   SyS_sendto+0x8a/0xb0 net/socket.c:1664
>   entry_SYSCALL_64_fastpath+0x13/0x94
>  RIP: 0033:0x44b479
>  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
>  RAX: ffda RBX: 2000 RCX: 0044b479
>  RDX: 0041 RSI: 20edd000 RDI: 0006
>  RBP: 007080a8 R08: 20b85fe4 R09: 001c
>  R10: 00040005 R11: 0286 R12: 
>  R13: 3760 R14: 006e5820 R15: 00ff8000
>  origin description: dst_saddr@sctp_v6_get_dst
>  local variable created at:
>   sk_fullsock include/net/sock.h:2321 [inline]
>   inet6_sk include/linux/ipv6.h:309 [inline]
>   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> ==
>  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
>  net/sctp/ipv6.c:517
>  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
>  01/01/2011
>  Call Trace:
>   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
>   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
>   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
>   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
>   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
>   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
>   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
>   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
>   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
>   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
>   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
>   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
>   sock_sendmsg_nosec net/socket.c:633 [inline]
>   sock_sendmsg net/socket.c:643 [inline]
>   SYSC_sendto+0x608/0x710 net/socket.c:1696
>   SyS_sendto+0x8a/0xb0 net/socket.c:1664
>   entry_SYSCALL_64_fastpath+0x13/0x94
>  RIP: 0033:0x44b479
>  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
>  RAX: ffda RBX: 2000 RCX: 0044b479
>  RDX: 0041 RSI: 20edd000 RDI: 0006
>  RBP: 007080a8 R08: 20b85fe4 R09: 001c
>  R10: 00040005 R11: 0286 R12: 
>  R13: 3760 R14: 006e5820 R15: 00ff8000
>  origin description: dst_saddr@sctp_v6_get_dst
>  local variable created at:
>   sk_fullsock include/net/sock.h:2321 [inline]
>   inet6_sk include/linux/ipv6.h:309 [inline]
>   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> ==
>
> Signed-off-by: Alexander Potapenko 
> Reviewed-by: Xin Long 
> ---
> v2 is identical to v1, resending per request by Marcelo Ricardo Leitner.
> ---
>  net/sctp/ipv6.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> index 2a186b201ad2..a15d691829c6 100644
> --- a/net/sctp/ipv6.c
> +++ b/net/sctp/ipv6.c
> @@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr *addr, struct 
> in6_addr *saddr,
> addr->sa.sa_family = 

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[吉藤英明]

Hi,

2017-08-15 3:43 GMT+09:00 Alexander Potapenko :
> KMSAN reported use of uninitialized sctp_addr->v4.sin_addr.s_addr and
> sctp_addr->v6.sin6_scope_id in sctp_v6_cmp_addr() (see below).
> Make sure all fields of an IPv6 address are initialized, which
> guarantees that the IPv4 fields are also initialized.
>
> ==
>  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
>  net/sctp/ipv6.c:517
>  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
>  01/01/2011
>  Call Trace:
>   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
>   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
>   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
>   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
>   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
>   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
>   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
>   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
>   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
>   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
>   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
>   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
>   sock_sendmsg_nosec net/socket.c:633 [inline]
>   sock_sendmsg net/socket.c:643 [inline]
>   SYSC_sendto+0x608/0x710 net/socket.c:1696
>   SyS_sendto+0x8a/0xb0 net/socket.c:1664
>   entry_SYSCALL_64_fastpath+0x13/0x94
>  RIP: 0033:0x44b479
>  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
>  RAX: ffda RBX: 2000 RCX: 0044b479
>  RDX: 0041 RSI: 20edd000 RDI: 0006
>  RBP: 007080a8 R08: 20b85fe4 R09: 001c
>  R10: 00040005 R11: 0286 R12: 
>  R13: 3760 R14: 006e5820 R15: 00ff8000
>  origin description: dst_saddr@sctp_v6_get_dst
>  local variable created at:
>   sk_fullsock include/net/sock.h:2321 [inline]
>   inet6_sk include/linux/ipv6.h:309 [inline]
>   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> ==
>  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
>  net/sctp/ipv6.c:517
>  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
>  01/01/2011
>  Call Trace:
>   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
>   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
>   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
>   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
>   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
>   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
>   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
>   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
>   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
>   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
>   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
>   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
>   sock_sendmsg_nosec net/socket.c:633 [inline]
>   sock_sendmsg net/socket.c:643 [inline]
>   SYSC_sendto+0x608/0x710 net/socket.c:1696
>   SyS_sendto+0x8a/0xb0 net/socket.c:1664
>   entry_SYSCALL_64_fastpath+0x13/0x94
>  RIP: 0033:0x44b479
>  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
>  RAX: ffda RBX: 2000 RCX: 0044b479
>  RDX: 0041 RSI: 20edd000 RDI: 0006
>  RBP: 007080a8 R08: 20b85fe4 R09: 001c
>  R10: 00040005 R11: 0286 R12: 
>  R13: 3760 R14: 006e5820 R15: 00ff8000
>  origin description: dst_saddr@sctp_v6_get_dst
>  local variable created at:
>   sk_fullsock include/net/sock.h:2321 [inline]
>   inet6_sk include/linux/ipv6.h:309 [inline]
>   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> ==
>
> Signed-off-by: Alexander Potapenko 
> Reviewed-by: Xin Long 
> ---
> v2 is identical to v1, resending per request by Marcelo Ricardo Leitner.
> ---
>  net/sctp/ipv6.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> index 2a186b201ad2..a15d691829c6 100644
> --- a/net/sctp/ipv6.c
> +++ b/net/sctp/ipv6.c
> @@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr *addr, struct 
> in6_addr *saddr,
> addr->sa.sa_family = AF_INET6;
> addr->v6.sin6_port = port;
> 

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Marcelo Ricardo Leitner]

On Mon, Aug 14, 2017 at 08:43:04PM +0200, Alexander Potapenko wrote:
> KMSAN reported use of uninitialized sctp_addr->v4.sin_addr.s_addr and
> sctp_addr->v6.sin6_scope_id in sctp_v6_cmp_addr() (see below).
> Make sure all fields of an IPv6 address are initialized, which
> guarantees that the IPv4 fields are also initialized.
> 
> ==
>  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
>  net/sctp/ipv6.c:517
>  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
>  01/01/2011
>  Call Trace:
>   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
>   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
>   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
>   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
>   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
>   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
>   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
>   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
>   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
>   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
>   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
>   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
>   sock_sendmsg_nosec net/socket.c:633 [inline]
>   sock_sendmsg net/socket.c:643 [inline]
>   SYSC_sendto+0x608/0x710 net/socket.c:1696
>   SyS_sendto+0x8a/0xb0 net/socket.c:1664
>   entry_SYSCALL_64_fastpath+0x13/0x94
>  RIP: 0033:0x44b479
>  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
>  RAX: ffda RBX: 2000 RCX: 0044b479
>  RDX: 0041 RSI: 20edd000 RDI: 0006
>  RBP: 007080a8 R08: 20b85fe4 R09: 001c
>  R10: 00040005 R11: 0286 R12: 
>  R13: 3760 R14: 006e5820 R15: 00ff8000
>  origin description: dst_saddr@sctp_v6_get_dst
>  local variable created at:
>   sk_fullsock include/net/sock.h:2321 [inline]
>   inet6_sk include/linux/ipv6.h:309 [inline]
>   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> ==
>  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
>  net/sctp/ipv6.c:517
>  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
>  01/01/2011
>  Call Trace:
>   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
>   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
>   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
>   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
>   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
>   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
>   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
>   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
>   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
>   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
>   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
>   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
>   sock_sendmsg_nosec net/socket.c:633 [inline]
>   sock_sendmsg net/socket.c:643 [inline]
>   SYSC_sendto+0x608/0x710 net/socket.c:1696
>   SyS_sendto+0x8a/0xb0 net/socket.c:1664
>   entry_SYSCALL_64_fastpath+0x13/0x94
>  RIP: 0033:0x44b479
>  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
>  RAX: ffda RBX: 2000 RCX: 0044b479
>  RDX: 0041 RSI: 20edd000 RDI: 0006
>  RBP: 007080a8 R08: 20b85fe4 R09: 001c
>  R10: 00040005 R11: 0286 R12: 
>  R13: 3760 R14: 006e5820 R15: 00ff8000
>  origin description: dst_saddr@sctp_v6_get_dst
>  local variable created at:
>   sk_fullsock include/net/sock.h:2321 [inline]
>   inet6_sk include/linux/ipv6.h:309 [inline]
>   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> ==
> 
> Signed-off-by: Alexander Potapenko 
> Reviewed-by: Xin Long 

Acked-by: Marcelo Ricardo Leitner 

> ---
> v2 is identical to v1, resending per request by Marcelo Ricardo Leitner.
> ---
>  net/sctp/ipv6.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> index 2a186b201ad2..a15d691829c6 100644
> --- a/net/sctp/ipv6.c
> +++ b/net/sctp/ipv6.c
> @@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr 

Re: [PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Marcelo Ricardo Leitner]

On Mon, Aug 14, 2017 at 08:43:04PM +0200, Alexander Potapenko wrote:
> KMSAN reported use of uninitialized sctp_addr->v4.sin_addr.s_addr and
> sctp_addr->v6.sin6_scope_id in sctp_v6_cmp_addr() (see below).
> Make sure all fields of an IPv6 address are initialized, which
> guarantees that the IPv4 fields are also initialized.
> 
> ==
>  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
>  net/sctp/ipv6.c:517
>  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
>  01/01/2011
>  Call Trace:
>   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
>   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
>   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
>   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
>   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
>   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
>   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
>   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
>   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
>   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
>   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
>   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
>   sock_sendmsg_nosec net/socket.c:633 [inline]
>   sock_sendmsg net/socket.c:643 [inline]
>   SYSC_sendto+0x608/0x710 net/socket.c:1696
>   SyS_sendto+0x8a/0xb0 net/socket.c:1664
>   entry_SYSCALL_64_fastpath+0x13/0x94
>  RIP: 0033:0x44b479
>  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
>  RAX: ffda RBX: 2000 RCX: 0044b479
>  RDX: 0041 RSI: 20edd000 RDI: 0006
>  RBP: 007080a8 R08: 20b85fe4 R09: 001c
>  R10: 00040005 R11: 0286 R12: 
>  R13: 3760 R14: 006e5820 R15: 00ff8000
>  origin description: dst_saddr@sctp_v6_get_dst
>  local variable created at:
>   sk_fullsock include/net/sock.h:2321 [inline]
>   inet6_sk include/linux/ipv6.h:309 [inline]
>   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> ==
>  BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
>  net/sctp/ipv6.c:517
>  CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
>  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
>  01/01/2011
>  Call Trace:
>   dump_stack+0x172/0x1c0 lib/dump_stack.c:42
>   is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
>   kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
>   native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
>   arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
>   arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
>   __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
>   sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
>   sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
>   sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
>   sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
>   inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
>   sock_sendmsg_nosec net/socket.c:633 [inline]
>   sock_sendmsg net/socket.c:643 [inline]
>   SYSC_sendto+0x608/0x710 net/socket.c:1696
>   SyS_sendto+0x8a/0xb0 net/socket.c:1664
>   entry_SYSCALL_64_fastpath+0x13/0x94
>  RIP: 0033:0x44b479
>  RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
>  RAX: ffda RBX: 2000 RCX: 0044b479
>  RDX: 0041 RSI: 20edd000 RDI: 0006
>  RBP: 007080a8 R08: 20b85fe4 R09: 001c
>  R10: 00040005 R11: 0286 R12: 
>  R13: 3760 R14: 006e5820 R15: 00ff8000
>  origin description: dst_saddr@sctp_v6_get_dst
>  local variable created at:
>   sk_fullsock include/net/sock.h:2321 [inline]
>   inet6_sk include/linux/ipv6.h:309 [inline]
>   sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
>   sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
> ==
> 
> Signed-off-by: Alexander Potapenko 
> Reviewed-by: Xin Long 

Acked-by: Marcelo Ricardo Leitner 

> ---
> v2 is identical to v1, resending per request by Marcelo Ricardo Leitner.
> ---
>  net/sctp/ipv6.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
> index 2a186b201ad2..a15d691829c6 100644
> --- a/net/sctp/ipv6.c
> +++ b/net/sctp/ipv6.c
> @@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr *addr, struct 
> in6_addr *saddr,
>   addr->sa.sa_family = 

[PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Alexander Potapenko]

KMSAN reported use of uninitialized sctp_addr->v4.sin_addr.s_addr and
sctp_addr->v6.sin6_scope_id in sctp_v6_cmp_addr() (see below).
Make sure all fields of an IPv6 address are initialized, which
guarantees that the IPv4 fields are also initialized.

==
 BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
 net/sctp/ipv6.c:517
 CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
 01/01/2011
 Call Trace:
  dump_stack+0x172/0x1c0 lib/dump_stack.c:42
  is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
  kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
  native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
  arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
  arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
  __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
  sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
  sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
  sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
  sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
  inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
  sock_sendmsg_nosec net/socket.c:633 [inline]
  sock_sendmsg net/socket.c:643 [inline]
  SYSC_sendto+0x608/0x710 net/socket.c:1696
  SyS_sendto+0x8a/0xb0 net/socket.c:1664
  entry_SYSCALL_64_fastpath+0x13/0x94
 RIP: 0033:0x44b479
 RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
 RAX: ffda RBX: 2000 RCX: 0044b479
 RDX: 0041 RSI: 20edd000 RDI: 0006
 RBP: 007080a8 R08: 20b85fe4 R09: 001c
 R10: 00040005 R11: 0286 R12: 
 R13: 3760 R14: 006e5820 R15: 00ff8000
 origin description: dst_saddr@sctp_v6_get_dst
 local variable created at:
  sk_fullsock include/net/sock.h:2321 [inline]
  inet6_sk include/linux/ipv6.h:309 [inline]
  sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
==
 BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
 net/sctp/ipv6.c:517
 CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
 01/01/2011
 Call Trace:
  dump_stack+0x172/0x1c0 lib/dump_stack.c:42
  is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
  kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
  native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
  arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
  arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
  __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
  sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
  sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
  sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
  sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
  inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
  sock_sendmsg_nosec net/socket.c:633 [inline]
  sock_sendmsg net/socket.c:643 [inline]
  SYSC_sendto+0x608/0x710 net/socket.c:1696
  SyS_sendto+0x8a/0xb0 net/socket.c:1664
  entry_SYSCALL_64_fastpath+0x13/0x94
 RIP: 0033:0x44b479
 RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
 RAX: ffda RBX: 2000 RCX: 0044b479
 RDX: 0041 RSI: 20edd000 RDI: 0006
 RBP: 007080a8 R08: 20b85fe4 R09: 001c
 R10: 00040005 R11: 0286 R12: 
 R13: 3760 R14: 006e5820 R15: 00ff8000
 origin description: dst_saddr@sctp_v6_get_dst
 local variable created at:
  sk_fullsock include/net/sock.h:2321 [inline]
  inet6_sk include/linux/ipv6.h:309 [inline]
  sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
==

Signed-off-by: Alexander Potapenko 
Reviewed-by: Xin Long 
---
v2 is identical to v1, resending per request by Marcelo Ricardo Leitner.
---
 net/sctp/ipv6.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 2a186b201ad2..a15d691829c6 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr *addr, struct 
in6_addr *saddr,
addr->sa.sa_family = AF_INET6;
addr->v6.sin6_port = port;
addr->v6.sin6_addr = *saddr;
+   addr->v6.sin6_flowinfo = 0;
+   addr->v6.sin6_scope_id = 0;
 }
 
 /* Compare addresses exactly.
-- 
2.14.0.434.g98096fd7a8-goog

[PATCH v2] sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

[Alexander Potapenko]

KMSAN reported use of uninitialized sctp_addr->v4.sin_addr.s_addr and
sctp_addr->v6.sin6_scope_id in sctp_v6_cmp_addr() (see below).
Make sure all fields of an IPv6 address are initialized, which
guarantees that the IPv4 fields are also initialized.

==
 BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
 net/sctp/ipv6.c:517
 CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
 01/01/2011
 Call Trace:
  dump_stack+0x172/0x1c0 lib/dump_stack.c:42
  is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
  kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
  native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
  arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
  arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
  __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
  sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
  sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
  sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
  sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
  inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
  sock_sendmsg_nosec net/socket.c:633 [inline]
  sock_sendmsg net/socket.c:643 [inline]
  SYSC_sendto+0x608/0x710 net/socket.c:1696
  SyS_sendto+0x8a/0xb0 net/socket.c:1664
  entry_SYSCALL_64_fastpath+0x13/0x94
 RIP: 0033:0x44b479
 RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
 RAX: ffda RBX: 2000 RCX: 0044b479
 RDX: 0041 RSI: 20edd000 RDI: 0006
 RBP: 007080a8 R08: 20b85fe4 R09: 001c
 R10: 00040005 R11: 0286 R12: 
 R13: 3760 R14: 006e5820 R15: 00ff8000
 origin description: dst_saddr@sctp_v6_get_dst
 local variable created at:
  sk_fullsock include/net/sock.h:2321 [inline]
  inet6_sk include/linux/ipv6.h:309 [inline]
  sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
==
 BUG: KMSAN: use of uninitialized memory in sctp_v6_cmp_addr+0x8d4/0x9f0
 net/sctp/ipv6.c:517
 CPU: 2 PID: 31056 Comm: syz-executor1 Not tainted 4.11.0-rc5+ #2944
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
 01/01/2011
 Call Trace:
  dump_stack+0x172/0x1c0 lib/dump_stack.c:42
  is_logbuf_locked mm/kmsan/kmsan.c:59 [inline]
  kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:938
  native_save_fl arch/x86/include/asm/irqflags.h:18 [inline]
  arch_local_save_flags arch/x86/include/asm/irqflags.h:72 [inline]
  arch_local_irq_save arch/x86/include/asm/irqflags.h:113 [inline]
  __msan_warning_32+0x61/0xb0 mm/kmsan/kmsan_instr.c:467
  sctp_v6_cmp_addr+0x8d4/0x9f0 net/sctp/ipv6.c:517
  sctp_v6_get_dst+0x8c7/0x1630 net/sctp/ipv6.c:290
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
  sctp_assoc_add_peer+0x66d/0x16f0 net/sctp/associola.c:651
  sctp_sendmsg+0x35a5/0x4f90 net/sctp/socket.c:1871
  inet_sendmsg+0x498/0x670 net/ipv4/af_inet.c:762
  sock_sendmsg_nosec net/socket.c:633 [inline]
  sock_sendmsg net/socket.c:643 [inline]
  SYSC_sendto+0x608/0x710 net/socket.c:1696
  SyS_sendto+0x8a/0xb0 net/socket.c:1664
  entry_SYSCALL_64_fastpath+0x13/0x94
 RIP: 0033:0x44b479
 RSP: 002b:7f6213f21c08 EFLAGS: 0286 ORIG_RAX: 002c
 RAX: ffda RBX: 2000 RCX: 0044b479
 RDX: 0041 RSI: 20edd000 RDI: 0006
 RBP: 007080a8 R08: 20b85fe4 R09: 001c
 R10: 00040005 R11: 0286 R12: 
 R13: 3760 R14: 006e5820 R15: 00ff8000
 origin description: dst_saddr@sctp_v6_get_dst
 local variable created at:
  sk_fullsock include/net/sock.h:2321 [inline]
  inet6_sk include/linux/ipv6.h:309 [inline]
  sctp_v6_get_dst+0x91/0x1630 net/sctp/ipv6.c:241
  sctp_transport_route+0x101/0x570 net/sctp/transport.c:292
==

Signed-off-by: Alexander Potapenko 
Reviewed-by: Xin Long 
---
v2 is identical to v1, resending per request by Marcelo Ricardo Leitner.
---
 net/sctp/ipv6.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/net/sctp/ipv6.c b/net/sctp/ipv6.c
index 2a186b201ad2..a15d691829c6 100644
--- a/net/sctp/ipv6.c
+++ b/net/sctp/ipv6.c
@@ -513,6 +513,8 @@ static void sctp_v6_to_addr(union sctp_addr *addr, struct 
in6_addr *saddr,
addr->sa.sa_family = AF_INET6;
addr->v6.sin6_port = port;
addr->v6.sin6_addr = *saddr;
+   addr->v6.sin6_flowinfo = 0;
+   addr->v6.sin6_scope_id = 0;
 }
 
 /* Compare addresses exactly.
-- 
2.14.0.434.g98096fd7a8-goog