Affected: Linux, Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem, Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP, Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP, Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

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

af_packet: fix vlan_get_protocol_dgram() vs MSG_PEEK

Blamed commit forgot MSG_PEEK case, allowing a crash [1] as found by syzbot.

Rework vlan_get_protocol_dgram() to not touch skb at all, so that it can be used from many cpus on the same skb.

Add a const qualifier to skb argument.

[1] skbuff: skb_under_panic: text:ffffffff8a8ccd05 len:29 put:14 head:ffff88807fc8e400 data:ffff88807fc8e3f4 tail:0x11 end:0x140 dev:<NULL> ------------[ cut here ]------------ kernel BUG at net/core/skbuff.c:206 ! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 1 UID: 0 PID: 5892 Comm: syz-executor883 Not tainted 6.13.0-rc4-syzkaller-00054-gd6ef8b40d075 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:skb_panic net/core/skbuff.c:206 [inline] RIP: 0010:skb_under_panic+0x14b/0x150 net/core/skbuff.c:216 Code: 0b 8d 48 c7 c6 86 d5 25 8e 48 8b 54 24 08 8b 0c 24 44 8b 44 24 04 4d 89 e9 50 41 54 41 57 41 56 e8 5a 69 79 f7 48 83 c4 20 90 <0f> 0b 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 RSP: 0018:ffffc900038d7638 EFLAGS: 00010282 RAX: 0000000000000087 RBX: dffffc0000000000 RCX: 609ffd18ea660600 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: ffff88802483c8d0 R08: ffffffff817f0a8c R09: 1ffff9200071ae60 R10: dffffc0000000000 R11: fffff5200071ae61 R12: 0000000000000140 R13: ffff88807fc8e400 R14: ffff88807fc8e3f4 R15: 000000000000…