kernel.git/net/sctp/ipv6.c, branch linux-4.16.y

sctp: handle two v4 addrs comparison in sctp_inet6_cmp_addr

2018-05-19T08:19:33Z

[ Upstream commit d625329b06e46bd20baf9ee40847d11982569204 ] Since sctp ipv6 socket also supports v4 addrs, it's possible to compare two v4 addrs in pf v6 .cmp_addr, sctp_inet6_cmp_addr. However after Commit 1071ec9d453a ("sctp: do not check port in sctp_inet6_cmp_addr"), it no longer calls af1->cmp_addr, which in this case is sctp_v4_cmp_addr, but calls __sctp_v6_cmp_addr where it handles them as two v6 addrs. It would cause a out of bounds crash. syzbot found this crash when trying to bind two v4 addrs to a v6 socket. This patch fixes it by adding the process for two v4 addrs in sctp_inet6_cmp_addr. Fixes: 1071ec9d453a ("sctp: do not check port in sctp_inet6_cmp_addr") Reported-by: syzbot+cd494c1dd681d4d93ebb@syzkaller.appspotmail.com Signed-off-by: Xin Long Acked-by: Neil Horman Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: do not check port in sctp_inet6_cmp_addr

2018-04-29T09:35:46Z

[ Upstream commit 1071ec9d453a38023579714b64a951a2fb982071 ] pf->cmp_addr() is called before binding a v6 address to the sock. It should not check ports, like in sctp_inet_cmp_addr. But sctp_inet6_cmp_addr checks the addr by invoking af(6)->cmp_addr, sctp_v6_cmp_addr where it also compares the ports. This would cause that setsockopt(SCTP_SOCKOPT_BINDX_ADD) could bind multiple duplicated IPv6 addresses after Commit 40b4f0fd74e4 ("sctp: lack the check for ports in sctp_v6_cmp_addr"). This patch is to remove af->cmp_addr called in sctp_inet6_cmp_addr, but do the proper check for both v6 addrs and v4mapped addrs. v1->v2: - define __sctp_v6_cmp_addr to do the common address comparison used for both pf and af v6 cmp_addr. Fixes: 40b4f0fd74e4 ("sctp: lack the check for ports in sctp_v6_cmp_addr") Reported-by: Jianwen Ji Signed-off-by: Xin Long Acked-by: Neil Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: do not leak kernel memory to user space

2018-04-12T10:30:00Z

[ Upstream commit 6780db244d6b1537d139dea0ec8aad10cf9e4adb ] syzbot produced a nice report [1] Issue here is that a recvmmsg() managed to leak 8 bytes of kernel memory to user space, because sin_zero (padding field) was not properly cleared. [1] BUG: KMSAN: uninit-value in copy_to_user include/linux/uaccess.h:184 [inline] BUG: KMSAN: uninit-value in move_addr_to_user+0x32e/0x530 net/socket.c:227 CPU: 1 PID: 3586 Comm: syzkaller481044 Not tainted 4.16.0+ #82 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 kmsan_report+0x142/0x240 mm/kmsan/kmsan.c:1067 kmsan_internal_check_memory+0x164/0x1d0 mm/kmsan/kmsan.c:1176 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199 copy_to_user include/linux/uaccess.h:184 [inline] move_addr_to_user+0x32e/0x530 net/socket.c:227 ___sys_recvmsg+0x4e2/0x810 net/socket.c:2211 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313 SYSC_recvmmsg+0x29b/0x3e0 net/socket.c:2394 SyS_recvmmsg+0x76/0xa0 net/socket.c:2378 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 RIP: 0033:0x4401c9 RSP: 002b:00007ffc56f73098 EFLAGS: 00000217 ORIG_RAX: 000000000000012b RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 00000000004401c9 RDX: 0000000000000001 RSI: 0000000020003ac0 RDI: 0000000000000003 RBP: 00000000006ca018 R08: 0000000020003bc0 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000217 R12: 0000000000401af0 R13: 0000000000401b80 R14: 0000000000000000 R15: 0000000000000000 Local variable description: ----addr@___sys_recvmsg Variable was created at: ___sys_recvmsg+0xd5/0x810 net/socket.c:2172 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313 Bytes 8-15 of 16 are uninitialized ================================================================== Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 3586 Comm: syzkaller481044 Tainted: G B 4.16.0+ #82 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x185/0x1d0 lib/dump_stack.c:53 panic+0x39d/0x940 kernel/panic.c:183 kmsan_report+0x238/0x240 mm/kmsan/kmsan.c:1083 kmsan_internal_check_memory+0x164/0x1d0 mm/kmsan/kmsan.c:1176 kmsan_copy_to_user+0x69/0x160 mm/kmsan/kmsan.c:1199 copy_to_user include/linux/uaccess.h:184 [inline] move_addr_to_user+0x32e/0x530 net/socket.c:227 ___sys_recvmsg+0x4e2/0x810 net/socket.c:2211 __sys_recvmmsg+0x54e/0xdb0 net/socket.c:2313 SYSC_recvmmsg+0x29b/0x3e0 net/socket.c:2394 SyS_recvmmsg+0x76/0xa0 net/socket.c:2378 do_syscall_64+0x309/0x430 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x3d/0xa2 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Cc: Vlad Yasevich Cc: Neil Horman Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

sctp: fix dst refcnt leak in sctp_v6_get_dst()

2018-02-06T02:21:13Z

When going through the bind address list in sctp_v6_get_dst() and the previously found address is better ('matchlen > bmatchlen'), the code continues to the next iteration without releasing currently held destination. Fix it by releasing 'bdst' before continue to the next iteration, and instead of introducing one more '!IS_ERR(bdst)' check for dst_release(), move the already existed one right after ip6_dst_lookup_flow(), i.e. we shouldn't proceed further if we get an error for the route lookup. Fixes: dbc2b5e9a09e ("sctp: fix src address selection if using secondary addresses for ipv6") Signed-off-by: Alexey Kodanev Acked-by: Neil Horman Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller

sctp: avoid compiler warning on implicit fallthru

2018-01-15T18:56:13Z

These fall-through are expected. Signed-off-by: Marcelo Ricardo Leitner Acked-by: Neil Horman Reviewed-by: Xin Long Signed-off-by: David S. Miller

net/sctp: Always set scope_id in sctp_inet6_skb_msgname

2017-11-16T14:00:30Z

Alexandar Potapenko while testing the kernel with KMSAN and syzkaller discovered that in some configurations sctp would leak 4 bytes of kernel stack. Working with his reproducer I discovered that those 4 bytes that are leaked is the scope id of an ipv6 address returned by recvmsg. With a little code inspection and a shrewd guess I discovered that sctp_inet6_skb_msgname only initializes the scope_id field for link local ipv6 addresses to the interface index the link local address pertains to instead of initializing the scope_id field for all ipv6 addresses. That is almost reasonable as scope_id's are meaniningful only for link local addresses. Set the scope_id in all other cases to 0 which is not a valid interface index to make it clear there is nothing useful in the scope_id field. There should be no danger of breaking userspace as the stack leak guaranteed that previously meaningless random data was being returned. Fixes: 372f525b495c ("SCTP: Resync with LKSCTP tree.") History-tree: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git Reported-by: Alexander Potapenko Tested-by: Alexander Potapenko Signed-off-by: "Eric W. Biederman" Signed-off-by: David S. Miller

sctp: fix some type cast warnings introduced since very beginning

2017-10-29T09:03:24Z

These warnings were found by running 'make C=2 M=net/sctp/'. They are there since very beginning. Note after this patch, there still one warning left in sctp_outq_flush(): sctp_chunk_fail(chunk, SCTP_ERROR_INV_STRM) Since it has been moved to sctp_stream_outq_migrate on net-next, to avoid the extra job when merging net-next to net, I will post the fix for it after the merging is done. Reported-by: Eric Dumazet Signed-off-by: Xin Long Signed-off-by: David S. Miller

sctp: full support for ipv6 ip_nonlocal_bind & IP_FREEBIND

2017-10-24T09:39:46Z

Commit 9b9742022888 ("sctp: support ipv6 nonlocal bind") introduced support for the above options as v4 sctp did, so patched sctp_v6_available(). In the v4 implementation it's enough, because sctp_inet_bind_verify() just returns with sctp_v4_available(). However sctp_inet6_bind_verify() has an extra check before that for link-local scope_id, which won't respect the above options. Added the checks before calling ipv6_chk_addr(), but not before the validation of scope_id. before (w/ both options): ./v6test fe80::10 sctp bind failed, errno: 99 (Cannot assign requested address) ./v6test fe80::10 tcp bind success, errno: 0 (Success) after (w/ both options): ./v6test fe80::10 sctp bind success, errno: 0 (Success) Signed-off-by: Laszlo Toth Reviewed-by: Xin Long Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2017-08-22T00:06:42Z

sctp: fully initialize the IPv6 address in sctp_v6_to_addr()

2017-08-18T23:00:47Z

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 Reviewed-by: Xin Long Acked-by: Marcelo Ricardo Leitner Signed-off-by: David S. Miller