| Message ID | 20170814184304.82747-1-glider@google.com |
|---|---|
| State | Changes Requested, archived |
| Delegated to: | David Miller |
| Headers | show |
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:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c > RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479 > RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006 > RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c > R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff > R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000 > 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:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c > RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479 > RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006 > RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c > R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff > R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000 > 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 <glider@google.com> > Reviewed-by: Xin Long <lucien.xin@gmail.com> Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> > --- > 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 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
Hi, 2017-08-15 3:43 GMT+09:00 Alexander Potapenko <glider@google.com>: > 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:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c > RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479 > RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006 > RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c > R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff > R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000 > 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:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c > RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479 > RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006 > RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c > R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff > R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000 > 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 <glider@google.com> > Reviewed-by: Xin Long <lucien.xin@gmail.com> > --- > 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; Please set flowinfo between port and addr. --yoshfuji > } > > /* Compare addresses exactly. > -- > 2.14.0.434.g98096fd7a8-goog >
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 <glider@google.com>: > > 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:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c > > RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479 > > RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006 > > RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c > > R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff > > R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000 > > 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:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c > > RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479 > > RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006 > > RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c > > R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff > > R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000 > > 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 <glider@google.com> > > Reviewed-by: Xin Long <lucien.xin@gmail.com> > > --- > > 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; > > Please set flowinfo between port and addr. Why? > > --yoshfuji > > > } > > > > /* Compare addresses exactly. > > -- > > 2.14.0.434.g98096fd7a8-goog > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-sctp" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >
From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> 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.
On Mon, Aug 14, 2017 at 07:40:51PM -0700, David Miller wrote: > From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> > 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_addr sin6_addr; /* 8 16 */ __u32 sin6_scope_id; /* 24 4 */ Current code: 12a1: ba 0a 00 00 00 mov $0xa,%edx 12a6: 49 8b 5f 68 mov 0x68(%r15),%rbx 12aa: 66 89 55 a0 mov %dx,-0x60(%rbp) union/struct start -----^ 12ae: 4d 8d 4f 68 lea 0x68(%r15),%r9 12b2: 49 8b 55 40 mov 0x40(%r13),%rdx 12b6: 66 c1 c0 08 rol $0x8,%ax (htons) 12ba: 4c 39 cb cmp %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 mov 0x38(%r13),%rax 12c9: 48 89 45 a8 mov %rax,-0x58(%rbp) and this are the ipv6 addr bytes ---^ 12cd: 74 30 je 12ff <sctp_v6_get_dst+0x37f> Alexander's: 12a1: ba 0a 00 00 00 mov $0xa,%edx 12a6: 49 8b 5f 68 mov 0x68(%r15),%rbx 12aa: 66 89 55 a0 mov %dx,-0x60(%rbp) 12ae: 4d 8d 4f 68 lea 0x68(%r15),%r9 12b2: 49 8b 55 40 mov 0x40(%r13),%rdx 12b6: c7 45 a4 00 00 00 00 movl $0x0,-0x5c(%rbp) 12bd: c7 45 b8 00 00 00 00 movl $0x0,-0x48(%rbp) 12c4: 66 c1 c0 08 rol $0x8,%ax 12c8: 4c 39 cb cmp %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 mov 0x38(%r13),%rax 12d7: 48 89 45 a8 mov %rax,-0x58(%rbp) 12db: 74 30 je 130d <sctp_v6_get_dst+0x38d> Hideaki's: 12a1: ba 0a 00 00 00 mov $0xa,%edx 12a6: 49 8b 5f 68 mov 0x68(%r15),%rbx 12aa: 66 89 55 a0 mov %dx,-0x60(%rbp) 12ae: 4d 8d 4f 68 lea 0x68(%r15),%r9 12b2: 49 8b 55 40 mov 0x40(%r13),%rdx 12b6: c7 45 a4 00 00 00 00 movl $0x0,-0x5c(%rbp) 12bd: c7 45 b8 00 00 00 00 movl $0x0,-0x48(%rbp) 12c4: 66 c1 c0 08 rol $0x8,%ax 12c8: 4c 39 cb cmp %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 mov 0x38(%r13),%rax 12d7: 48 89 45 a8 mov %rax,-0x58(%rbp) 12db: 74 30 je 130d <sctp_v6_get_dst+0x38d> 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
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)
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
================================================================== 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:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479 RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006 RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000 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:00007f6213f21c08 EFLAGS: 00000286 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000020000000 RCX: 000000000044b479 RDX: 0000000000000041 RSI: 0000000020edd000 RDI: 0000000000000006 RBP: 00000000007080a8 R08: 0000000020b85fe4 R09: 000000000000001c R10: 0000000000040005 R11: 0000000000000286 R12: 00000000ffffffff R13: 0000000000003760 R14: 00000000006e5820 R15: 0000000000ff8000 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 <glider@google.com> Reviewed-by: Xin Long <lucien.xin@gmail.com> --- 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.