This is a note to let you know that I've just added the patch titled
ip6_gre: better validate user provided tunnel names
to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: ip6_gre-better-validate-user-provided-tunnel-names.patch and it can be found in the queue-4.9 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From foo@baz Wed Apr 11 10:26:56 CEST 2018
From: Eric Dumazet edumazet@google.com Date: Thu, 5 Apr 2018 06:39:29 -0700 Subject: ip6_gre: better validate user provided tunnel names
From: Eric Dumazet edumazet@google.com
[ Upstream commit 5f42df013b8bc1b6511af7a04bf93b014884ae2a ]
Use dev_valid_name() to make sure user does not provide illegal device name.
syzbot caught the following bug :
BUG: KASAN: stack-out-of-bounds in strlcpy include/linux/string.h:300 [inline] BUG: KASAN: stack-out-of-bounds in ip6gre_tunnel_locate+0x334/0x860 net/ipv6/ip6_gre.c:339 Write of size 20 at addr ffff8801afb9f7b8 by task syzkaller851048/4466
CPU: 1 PID: 4466 Comm: syzkaller851048 Not tainted 4.16.0+ #1 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+0x1b9/0x29f lib/dump_stack.c:53 print_address_description+0x6c/0x20b mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.7+0xac/0x2f5 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 memcpy+0x37/0x50 mm/kasan/kasan.c:303 strlcpy include/linux/string.h:300 [inline] ip6gre_tunnel_locate+0x334/0x860 net/ipv6/ip6_gre.c:339 ip6gre_tunnel_ioctl+0x69d/0x12e0 net/ipv6/ip6_gre.c:1195 dev_ifsioc+0x43e/0xb90 net/core/dev_ioctl.c:334 dev_ioctl+0x69a/0xcc0 net/core/dev_ioctl.c:525 sock_ioctl+0x47e/0x680 net/socket.c:1015 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:500 [inline] do_vfs_ioctl+0x1cf/0x1650 fs/ioctl.c:684 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701 SYSC_ioctl fs/ioctl.c:708 [inline] SyS_ioctl+0x24/0x30 fs/ioctl.c:706 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7
Fixes: c12b395a4664 ("gre: Support GRE over IPv6") Signed-off-by: Eric Dumazet edumazet@google.com Reported-by: syzbot syzkaller@googlegroups.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/ip6_gre.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)
--- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -319,11 +319,13 @@ static struct ip6_tnl *ip6gre_tunnel_loc if (t || !create) return t;
- if (parms->name[0]) + if (parms->name[0]) { + if (!dev_valid_name(parms->name)) + return NULL; strlcpy(name, parms->name, IFNAMSIZ); - else + } else { strcpy(name, "ip6gre%d"); - + } dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN, ip6gre_tunnel_setup); if (!dev)
Patches currently in stable-queue which might be from edumazet@google.com are
queue-4.9/tcp-better-validation-of-received-ack-sequences.patch queue-4.9/sctp-sctp_sockaddr_af-must-check-minimal-addr-length-for-af_inet6.patch queue-4.9/net-fix-possible-out-of-bound-read-in-skb_network_protocol.patch queue-4.9/pptp-remove-a-buggy-dst-release-in-pptp_connect.patch queue-4.9/x86-asm-don-t-use-rbp-as-a-temporary-register-in-csum_partial_copy_generic.patch queue-4.9/net-fool-proof-dev_valid_name.patch queue-4.9/ipv6-the-entire-ipv6-header-chain-must-fit-the-first-fragment.patch queue-4.9/vti6-better-validate-user-provided-tunnel-names.patch queue-4.9/ipv6-sit-better-validate-user-provided-tunnel-names.patch queue-4.9/ip6_tunnel-better-validate-user-provided-tunnel-names.patch queue-4.9/sctp-do-not-leak-kernel-memory-to-user-space.patch queue-4.9/ip_tunnel-better-validate-user-provided-tunnel-names.patch queue-4.9/skbuff-only-inherit-relevant-tx_flags.patch queue-4.9/netlink-make-sure-nladdr-has-correct-size-in-netlink_connect.patch queue-4.9/ip6_gre-better-validate-user-provided-tunnel-names.patch