DEBIAN-CVE-2022-48839

In the Linux kernel, the following vulnerability has been resolved: net/packet: fix slab-out-of-bounds access in packetrecvmsg() syzbot found that when an AFPACKET socket is using PACKETCOPYTHRESH and mmap operations, tpacketrcv() is queueing skbs with garbage in skb->cb[], triggering a too big copy [1] Presumably, users of afpacket using mmap() already gets correct metadata from the mapped buffer, we can simply make sure to clear 12 bytes that might be copied to user space later. BUG: KASAN: stack-out-of-bounds in memcpy include/linux/fortify-string.h:225 [inline] BUG: KASAN: stack-out-of-bounds in packetrecvmsg+0x56c/0x1150 net/packet/afpacket.c:3489 Write of size 165 at addr ffffc9000385fb78 by task syz-executor233/3631 CPU: 0 PID: 3631 Comm: syz-executor233 Not tainted 5.17.0-rc7-syzkaller-02396-g0b3660695e80 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <TASK> dumpstack lib/dumpstack.c:88 [inline] dumpstacklvl+0xcd/0x134 lib/dumpstack.c:106 printaddressdescription.constprop.0.cold+0xf/0x336 mm/kasan/report.c:255 _kasanreport mm/kasan/report.c:442 [inline] kasanreport.cold+0x83/0xdf mm/kasan/report.c:459 checkregioninline mm/kasan/generic.c:183 [inline] kasancheckrange+0x13d/0x180 mm/kasan/generic.c:189 memcpy+0x39/0x60 mm/kasan/shadow.c:66 memcpy include/linux/fortify-string.h:225 [inline] packetrecvmsg+0x56c/0x1150 net/packet/afpacket.c:3489 sockrecvmsgnosec net/socket.c:948 [inline] sockrecvmsg net/socket.c:966 [inline] sockrecvmsg net/socket.c:962 [inline] sysrecvmsg+0x2c4/0x600 net/socket.c:2632 sysrecvmsg+0x127/0x200 net/socket.c:2674 _sysrecvmsg+0xe2/0x1a0 net/socket.c:2704 dosyscallx64 arch/x86/entry/common.c:50 [inline] dosyscall64+0x35/0xb0 arch/x86/entry/common.c:80 entrySYSCALL64afterhwframe+0x44/0xae RIP: 0033:0x7fdfd5954c29 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 41 15 00 00 90 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 c0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffcf8e71e48 EFLAGS: 00000246 ORIGRAX: 000000000000002f RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fdfd5954c29 RDX: 0000000000000000 RSI: 0000000020000500 RDI: 0000000000000005 RBP: 0000000000000000 R08: 000000000000000d R09: 000000000000000d R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffcf8e71e60 R13: 00000000000f4240 R14: 000000000000c1ff R15: 00007ffcf8e71e54 </TASK> addr ffffc9000385fb78 is located in stack of task syz-executor233/3631 at offset 32 in frame: sys_recvmsg+0x0/0x600 include/linux/uio.h:246 this frame has 1 object: [32, 160) 'addr' Memory state around the buggy address: ffffc9000385fa80: 00 04 f3 f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 ffffc9000385fb00: 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 >ffffc9000385fb80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f3 ^ ffffc9000385fc00: f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00 f1 ffffc9000385fc80: f1 f1 f1 00 f2 f2 f2 00 f2 f2 f2 00 00 00 00 00 ==================================================================