CVE-2024-26625

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

llc: call sock_orphan() at release time

syzbot reported an interesting trace [1] caused by a stale sk->sk_wq pointer in a closed llc socket.

In commit ff7b11aa481f ("net: socket: set sock->sk to NULL after calling protoops::release()") Eric Biggers hinted that some protocols are missing a sockorphan(), we need to perform a full audit.

In net-next, I plan to clear sock->sk from sock_orphan() and amend Eric patch to add a warning.

[1] BUG: KASAN: slab-use-after-free in listempty include/linux/list.h:373 [inline] BUG: KASAN: slab-use-after-free in waitqueueactive include/linux/wait.h:127 [inline] BUG: KASAN: slab-use-after-free in sockdefwritespacewfree net/core/sock.c:3384 [inline] BUG: KASAN: slab-use-after-free in sock_wfree+0x9a8/0x9d0 net/core/sock.c:2468 Read of size 8 at addr ffff88802f4fc880 by task ksoftirqd/1/27

CPU: 1 PID: 27 Comm: ksoftirqd/1 Not tainted 6.8.0-rc1-syzkaller-00049-g6098d87eaf31 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: <TASK> _dumpstack lib/dumpstack.c:88 [inline] dumpstacklvl+0xd9/0x1b0 lib/dumpstack.c:106 printaddressdescription mm/kasan/report.c:377 [inline] printreport+0xc4/0x620 mm/kasan/report.c:488 kasanreport+0xda/0x110 mm/kasan/report.c:601 listempty include/linux/list.h:373 [inline] waitqueueactive include/linux/wait.h:127 [inline] sockdefwritespacewfree net/core/sock.c:3384 [inline] sockwfree+0x9a8/0x9d0 net/core/sock.c:2468 skbreleaseheadstate+0xa3/0x2b0 net/core/skbuff.c:1080 skbreleaseall net/core/skbuff.c:1092 [inline] napiconsumeskb+0x119/0x2b0 net/core/skbuff.c:1404 e1000unmapandfreetxresource+0x144/0x200 drivers/net/ethernet/intel/e1000/e1000main.c:1970 e1000cleantxirq drivers/net/ethernet/intel/e1000/e1000main.c:3860 [inline] e1000clean+0x4a1/0x26e0 drivers/net/ethernet/intel/e1000/e1000main.c:3801 _napipoll.constprop.0+0xb4/0x540 net/core/dev.c:6576 napipoll net/core/dev.c:6645 [inline] netrxaction+0x956/0xe90 net/core/dev.c:6778 _dosoftirq+0x21a/0x8de kernel/softirq.c:553 runksoftirqd kernel/softirq.c:921 [inline] runksoftirqd+0x31/0x60 kernel/softirq.c:913 smpbootthreadfn+0x660/0xa10 kernel/smpboot.c:164 kthread+0x2c6/0x3a0 kernel/kthread.c:388 retfromfork+0x45/0x80 arch/x86/kernel/process.c:147 retfromforkasm+0x11/0x20 arch/x86/entry/entry_64.S:242 </TASK>

Allocated by task 5167: kasansavestack+0x33/0x50 mm/kasan/common.c:47 kasansavetrack+0x14/0x30 mm/kasan/common.c:68 unpoisonslabobject mm/kasan/common.c:314 [inline] _kasanslaballoc+0x81/0x90 mm/kasan/common.c:340 kasanslaballoc include/linux/kasan.h:201 [inline] slabpostallochook mm/slub.c:3813 [inline] slaballocnode mm/slub.c:3860 [inline] kmemcachealloclru+0x142/0x6f0 mm/slub.c:3879 allocinodesb include/linux/fs.h:3019 [inline] sockallocinode+0x25/0x1c0 net/socket.c:308 allocinode+0x5d/0x220 fs/inode.c:260 newinodepseudo+0x16/0x80 fs/inode.c:1005 sockalloc+0x40/0x270 net/socket.c:634 _sockcreate+0xbc/0x800 net/socket.c:1535 sockcreate net/socket.c:1622 [inline] _syssocketcreate net/socket.c:1659 [inline] _syssocket+0x14c/0x260 net/socket.c:1706 _dosyssocket net/socket.c:1720 [inline] _sesyssocket net/socket.c:1718 [inline] _x64syssocket+0x72/0xb0 net/socket.c:1718 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0xd3/0x250 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x63/0x6b

Freed by task 0: kasansavestack+0x33/0x50 mm/kasan/common.c:47 kasansavetrack+0x14/0x30 mm/kasan/common.c:68 kasansavefreeinfo+0x3f/0x60 mm/kasan/generic.c:640 poisonslabobject mm/kasan/common.c:241 [inline] _kasanslabfree+0x121/0x1b0 mm/kasan/common.c:257 kasanslabfree include/linux/kasan.h:184 [inline] slabfreehook mm/slub.c:2121 [inlin ---truncated---