CVE-2022-50363

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

skmsg: pass gfp argument to allocskmsg()

syzbot found that allocskmsg() could be called from a non sleepable context. skpsockverdictrecv() uses rcuread_lock() protection.

We need the callers to pass a gfp_t argument to avoid issues.

syzbot report was:

BUG: sleeping function called from invalid context at include/linux/sched/mm.h:274 inatomic(): 0, irqsdisabled(): 0, nonblock: 0, pid: 3613, name: syz-executor414 preemptcount: 0, expected: 0 RCU nest depth: 1, expected: 0 INFO: lockdep is turned off. CPU: 0 PID: 3613 Comm: syz-executor414 Not tainted 6.0.0-syzkaller-09589-g55be6084c8e0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022 Call Trace: <TASK> _dumpstack lib/dumpstack.c:88 [inline] dumpstacklvl+0x1e3/0x2cb lib/dumpstack.c:106 _mightresched+0x538/0x6a0 kernel/sched/core.c:9877 mightalloc include/linux/sched/mm.h:274 [inline] slabpreallochook mm/slab.h:700 [inline] slaballocnode mm/slub.c:3162 [inline] slaballoc mm/slub.c:3256 [inline] kmemcachealloctrace+0x59/0x310 mm/slub.c:3287 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:733 [inline] allocskmsg net/core/skmsg.c:507 [inline] skpsockskbingressself+0x5c/0x330 net/core/skmsg.c:600 skpsockverdictapply+0x395/0x440 net/core/skmsg.c:1014 skpsockverdictrecv+0x34d/0x560 net/core/skmsg.c:1201 tcpreadskb+0x4a1/0x790 net/ipv4/tcp.c:1770 tcprcvestablished+0x129d/0x1a10 net/ipv4/tcpinput.c:5971 tcpv4dorcv+0x479/0xac0 net/ipv4/tcpipv4.c:1681 skbacklogrcv include/net/sock.h:1109 [inline] _releasesock+0x1d8/0x4c0 net/core/sock.c:2906 releasesock+0x5d/0x1c0 net/core/sock.c:3462 tcpsendmsg+0x36/0x40 net/ipv4/tcp.c:1483 socksendmsgnosec net/socket.c:714 [inline] socksendmsg net/socket.c:734 [inline] _syssendto+0x46d/0x5f0 net/socket.c:2117 _dosyssendto net/socket.c:2129 [inline] _sesyssendto net/socket.c:2125 [inline] _x64syssendto+0xda/0xf0 net/socket.c:2125 dosyscallx64 arch/x86/entry/common.c:50 [inline] dosyscall64+0x2b/0x70 arch/x86/entry/common.c:80 entrySYSCALL64after_hwframe+0x63/0xcd