CVE-2022-50295

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> io_uring/msg_ring: Fix NULL pointer dereference in io_msg_send_fd()<br /> <br /> Syzkaller produced the below call trace:<br /> <br /> BUG: KASAN: null-ptr-deref in io_msg_ring+0x3cb/0x9f0<br /> Write of size 8 at addr 0000000000000070 by task repro/16399<br /> <br /> CPU: 0 PID: 16399 Comm: repro Not tainted 6.1.0-rc1 #28<br /> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7<br /> Call Trace:<br /> <br /> dump_stack_lvl+0xcd/0x134<br /> ? io_msg_ring+0x3cb/0x9f0<br /> kasan_report+0xbc/0xf0<br /> ? io_msg_ring+0x3cb/0x9f0<br /> kasan_check_range+0x140/0x190<br /> io_msg_ring+0x3cb/0x9f0<br /> ? io_msg_ring_prep+0x300/0x300<br /> io_issue_sqe+0x698/0xca0<br /> io_submit_sqes+0x92f/0x1c30<br /> __do_sys_io_uring_enter+0xae4/0x24b0<br /> ....<br /> RIP: 0033:0x7f2eaf8f8289<br /> RSP: 002b:00007fff40939718 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa<br /> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f2eaf8f8289<br /> RDX: 0000000000000000 RSI: 0000000000006f71 RDI: 0000000000000004<br /> RBP: 00007fff409397a0 R08: 0000000000000000 R09: 0000000000000039<br /> R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004006d0<br /> R13: 00007fff40939880 R14: 0000000000000000 R15: 0000000000000000<br /> <br /> Kernel panic - not syncing: panic_on_warn set ...<br /> <br /> We don&amp;#39;t have a NULL check on file_ptr in io_msg_send_fd() function,<br /> so when file_ptr is NUL src_file is also NULL and get_file()<br /> dereferences a NULL pointer and leads to above crash.<br /> <br /> Add a NULL check to fix this issue.