A security regression (CVE-2006-5051) was discovered in OpenSSH's server (sshd). There is a race condition which can lead sshd to handle some signals in an unsafe manner. An unauthenticated, remote attacker may be able to trigger it by failing to authenticate within a set time period.

In the Linux kernel, the following vulnerability has been resolved:

arp: Prevent overflow in arpreqget().

syzkaller reported an overflown write in arpreqget(). [0]

When ioctl(SIOCGARP) is issued, arpreqget() looks up an neighbour entry and copies neigh->ha to struct arpreq.arpha.sadata.

The arpha here is struct sockaddr, not struct sockaddrstorage, so the sadata buffer is just 14 bytes.

In the splat below, 2 bytes are overflown to the next int field, arpflags. We initialise the field just after the memcpy(), so it's not a problem.

However, when dev->addrlen is greater than 22 (e.g. MAXADDRLEN), arpnetmask is overwritten, which could be set as htonl(0xFFFFFFFFUL) in arpioctl() before calling arpreqget().

To avoid the overflow, let's limit the max length of memcpy().

Note that commit b5f0de6df6dc ("net: dev: Convert sadata to flexible array in struct sockaddr") just silenced syzkaller.

[0]: memcpy: detected field-spanning write (size 16) of single field "r->arpha.sadata" at net/ipv4/arp.c:1128 (size 14) WARNING: CPU: 0 PID: 144638 at net/ipv4/arp.c:1128 arpreqget+0x411/0x4a0 net/ipv4/arp.c:1128 Modules linked in: CPU: 0 PID: 144638 Comm: syz-executor.4 Not tainted 6.1.74 #31 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-5 04/01/2014 RIP: 0010:arpreqget+0x411/0x4a0 net/ipv4/arp.c:1128 Code: fd ff ff e8 41 42 de fb b9 0e 00 00 00 4c 89 fe 48 c7 c2 20 6d ab 87 48 c7 c7 80 6d ab 87 c6 05 25 af 72 04 01 e8 5f 8d ad fb <0f> 0b e9 6c fd ff ff e8 13 42 de fb be 03 00 00 00 4c 89 e7 e8 a6 RSP: 0018:ffffc900050b7998 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88803a815000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8641a44a RDI: 0000000000000001 RBP: ffffc900050b7a98 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 203a7970636d656d R12: ffff888039c54000 R13: 1ffff92000a16f37 R14: ffff88803a815084 R15: 0000000000000010 FS: 00007f172bf306c0(0000) GS:ffff88805aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f172b3569f0 CR3: 0000000057f12005 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: arpioctl+0x33f/0x4b0 net/ipv4/arp.c:1261 inetioctl+0x314/0x3a0 net/ipv4/afinet.c:981 sockdoioctl+0xdf/0x260 net/socket.c:1204 sockioctl+0x3ef/0x650 net/socket.c:1321 vfsioctl fs/ioctl.c:51 [inline] dosysioctl fs/ioctl.c:870 [inline] sesysioctl fs/ioctl.c:856 [inline] x64sysioctl+0x18e/0x220 fs/ioctl.c:856 dosyscallx64 arch/x86/entry/common.c:51 [inline] dosyscall64+0x37/0x90 arch/x86/entry/common.c:81 entrySYSCALL64afterhwframe+0x64/0xce RIP: 0033:0x7f172b262b8d Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f172bf300b8 EFLAGS: 00000246 ORIGRAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f172b3abf80 RCX: 00007f172b262b8d RDX: 0000000020000000 RSI: 0000000000008954 RDI: 0000000000000003 RBP: 00007f172b2d3493 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f172b3abf80 R15: 00007f172bf10000

In the Linux kernel, the following vulnerability has been resolved:

ip6tunnel: fix NEXTHDRFRAGMENT handling in ip6tnlparsetlvenclim()

syzbot pointed out [1] that NEXTHDRFRAGMENT handling is broken.

Reading fragoff can only be done if we pulled enough bytes to skb->head. Currently we might access garbage.

[1] BUG: KMSAN: uninit-value in ip6tnlparsetlvenclim+0x94f/0xbb0 ip6tnlparsetlvenclim+0x94f/0xbb0 ipxip6tnlxmit net/ipv6/ip6tunnel.c:1326 [inline] ip6tnlstartxmit+0xab2/0x1a70 net/ipv6/ip6tunnel.c:1432 netdevstartxmit include/linux/netdevice.h:4940 [inline] netdevstartxmit include/linux/netdevice.h:4954 [inline] xmitone net/core/dev.c:3548 [inline] devhardstartxmit+0x247/0xa10 net/core/dev.c:3564 devqueuexmit+0x33b8/0x5130 net/core/dev.c:4349 devqueuexmit include/linux/netdevice.h:3134 [inline] neighconnectedoutput+0x569/0x660 net/core/neighbour.c:1592 neighoutput include/net/neighbour.h:542 [inline] ip6finishoutput2+0x23a9/0x2b30 net/ipv6/ip6output.c:137 ip6finishoutput+0x855/0x12b0 net/ipv6/ip6output.c:222 NFHOOKCOND include/linux/netfilter.h:303 [inline] ip6output+0x323/0x610 net/ipv6/ip6output.c:243 dstoutput include/net/dst.h:451 [inline] ip6localout+0xe9/0x140 net/ipv6/outputcore.c:155 ip6sendskb net/ipv6/ip6output.c:1952 [inline] ip6pushpendingframes+0x1f9/0x560 net/ipv6/ip6output.c:1972 rawv6pushpendingframes+0xbe8/0xdf0 net/ipv6/raw.c:582 rawv6sendmsg+0x2b66/0x2e70 net/ipv6/raw.c:920 inetsendmsg+0x105/0x190 net/ipv4/afinet.c:847 socksendmsgnosec net/socket.c:730 [inline] socksendmsg net/socket.c:745 [inline] syssendmsg+0x9c2/0xd60 net/socket.c:2584 syssendmsg+0x28d/0x3c0 net/socket.c:2638 syssendmsg net/socket.c:2667 [inline] dosyssendmsg net/socket.c:2676 [inline] sesyssendmsg net/socket.c:2674 [inline] x64syssendmsg+0x307/0x490 net/socket.c:2674 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0x44/0x110 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x63/0x6b

Uninit was created at: slabpostallochook+0x129/0xa70 mm/slab.h:768 slaballocnode mm/slub.c:3478 [inline] kmemcacheallocnode+0x5c9/0x970 mm/slub.c:3517 dokmallocnode mm/slabcommon.c:1006 [inline] kmallocnodetrackcaller+0x118/0x3c0 mm/slabcommon.c:1027 kmallocreserve+0x249/0x4a0 net/core/skbuff.c:582 pskbexpandhead+0x226/0x1a00 net/core/skbuff.c:2098 pskbpulltail+0x13b/0x2310 net/core/skbuff.c:2655 pskbmaypullreason include/linux/skbuff.h:2673 [inline] pskbmaypull include/linux/skbuff.h:2681 [inline] ip6tnlparsetlvenclim+0x901/0xbb0 net/ipv6/ip6tunnel.c:408 ipxip6tnlxmit net/ipv6/ip6tunnel.c:1326 [inline] ip6tnlstartxmit+0xab2/0x1a70 net/ipv6/ip6tunnel.c:1432 netdevstartxmit include/linux/netdevice.h:4940 [inline] netdevstartxmit include/linux/netdevice.h:4954 [inline] xmitone net/core/dev.c:3548 [inline] devhardstartxmit+0x247/0xa10 net/core/dev.c:3564 devqueuexmit+0x33b8/0x5130 net/core/dev.c:4349 devqueuexmit include/linux/netdevice.h:3134 [inline] neighconnectedoutput+0x569/0x660 net/core/neighbour.c:1592 neighoutput include/net/neighbour.h:542 [inline] ip6finishoutput2+0x23a9/0x2b30 net/ipv6/ip6output.c:137 ip6finishoutput+0x855/0x12b0 net/ipv6/ip6output.c:222 NFHOOKCOND include/linux/netfilter.h:303 [inline] ip6output+0x323/0x610 net/ipv6/ip6output.c:243 dstoutput include/net/dst.h:451 [inline] ip6localout+0xe9/0x140 net/ipv6/outputcore.c:155 ip6sendskb net/ipv6/ip6output.c:1952 [inline] ip6pushpendingframes+0x1f9/0x560 net/ipv6/ip6output.c:1972 rawv6pushpendingframes+0xbe8/0xdf0 net/ipv6/raw.c:582 rawv6sendmsg+0x2b66/0x2e70 net/ipv6/raw.c:920 inetsendmsg+0x105/0x190 net/ipv4/afinet.c:847 socksendmsgnosec net/socket.c:730 [inline] socksendmsg net/socket.c:745 [inline] syssendmsg+0x9c2/0xd60 net/socket.c:2584 syssendmsg+0x28d/0x3c0 net/socket.c:2638 syssendmsg net/socket.c:2667 [inline] dosyssendms ---truncated---

In the Linux kernel, the following vulnerability has been resolved:

ip6tunnel: make sure to pull inner header in ip6tnlrcv()

syzbot found ip6tnlrcv() could access unitiliazed data [1].

Call pskbinetmaypull() to fix this, and initialize ipv6h variable after this call as it can change skb->head.

[1] BUG: KMSAN: uninit-value in INETECNdecapsulate include/net/inetecn.h:253 [inline] BUG: KMSAN: uninit-value in INETECNdecapsulate include/net/inetecn.h:275 [inline] BUG: KMSAN: uninit-value in IP6ECNdecapsulate+0x7df/0x1e50 include/net/inetecn.h:321 INETECNdecapsulate include/net/inetecn.h:253 [inline] INETECNdecapsulate include/net/inetecn.h:275 [inline] IP6ECNdecapsulate+0x7df/0x1e50 include/net/inetecn.h:321 ip6ip6dscpecndecapsulate+0x178/0x1b0 net/ipv6/ip6tunnel.c:727 ip6tnlrcv+0xd4e/0x1590 net/ipv6/ip6tunnel.c:845 ip6tnlrcv+0xce/0x100 net/ipv6/ip6tunnel.c:888 grercv+0x143f/0x1870 ip6protocoldeliverrcu+0xda6/0x2a60 net/ipv6/ip6input.c:438 ip6inputfinish net/ipv6/ip6input.c:483 [inline] NFHOOK include/linux/netfilter.h:314 [inline] ip6input+0x15d/0x430 net/ipv6/ip6input.c:492 ip6mcinput+0xa7e/0xc80 net/ipv6/ip6input.c:586 dstinput include/net/dst.h:461 [inline] ip6rcvfinish+0x5db/0x870 net/ipv6/ip6input.c:79 NFHOOK include/linux/netfilter.h:314 [inline] ipv6rcv+0xda/0x390 net/ipv6/ip6input.c:310 netifreceiveskbonecore net/core/dev.c:5532 [inline] netifreceiveskb+0x1a6/0x5a0 net/core/dev.c:5646 netifreceiveskbinternal net/core/dev.c:5732 [inline] netifreceiveskb+0x58/0x660 net/core/dev.c:5791 tunrxbatched+0x3ee/0x980 drivers/net/tun.c:1555 tungetuser+0x53af/0x66d0 drivers/net/tun.c:2002 tunchrwriteiter+0x3af/0x5d0 drivers/net/tun.c:2048 callwriteiter include/linux/fs.h:2084 [inline] newsyncwrite fs/readwrite.c:497 [inline] vfswrite+0x786/0x1200 fs/readwrite.c:590 ksyswrite+0x20f/0x4c0 fs/readwrite.c:643 dosyswrite fs/readwrite.c:655 [inline] sesyswrite fs/readwrite.c:652 [inline] x64syswrite+0x93/0xd0 fs/readwrite.c:652 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0x6d/0x140 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x63/0x6b

Uninit was created at: slabpostallochook+0x129/0xa70 mm/slab.h:768 slaballocnode mm/slub.c:3478 [inline] kmemcacheallocnode+0x5e9/0xb10 mm/slub.c:3523 kmallocreserve+0x13d/0x4a0 net/core/skbuff.c:560 allocskb+0x318/0x740 net/core/skbuff.c:651 allocskb include/linux/skbuff.h:1286 [inline] allocskbwithfrags+0xc8/0xbd0 net/core/skbuff.c:6334 sockallocsendpskb+0xa80/0xbf0 net/core/sock.c:2787 tunallocskb drivers/net/tun.c:1531 [inline] tungetuser+0x1e8a/0x66d0 drivers/net/tun.c:1846 tunchrwriteiter+0x3af/0x5d0 drivers/net/tun.c:2048 callwriteiter include/linux/fs.h:2084 [inline] newsyncwrite fs/readwrite.c:497 [inline] vfswrite+0x786/0x1200 fs/readwrite.c:590 ksyswrite+0x20f/0x4c0 fs/readwrite.c:643 dosyswrite fs/readwrite.c:655 [inline] sesyswrite fs/readwrite.c:652 [inline] x64syswrite+0x93/0xd0 fs/readwrite.c:652 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0x6d/0x140 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x63/0x6b

CPU: 0 PID: 5034 Comm: syz-executor331 Not tainted 6.7.0-syzkaller-00562-g9f8413c4a66f #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023

Out-of-bounds write in the BIOS firmware for some Intel(R) Processors may allow an authenticated user to potentially enable escalation of privilege via local access.