CVE-2022-50270

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

f2fs: fix the assign logic of iocb

commit 18ae8d12991b ("f2fs: show more DIO information in tracepoint")

introduces iocb field in 'f2fs_direct_IO_enter' trace event

And it only assigns the pointer and later it accesses its field

in trace print log.

Unable to handle kernel paging request at virtual address ffffffc04cef3d30

Mem abort info:

ESR = 0x96000007

EC = 0x25: DABT (current EL), IL = 32 bits

pc : trace_raw_output_f2fs_direct_IO_enter+0x54/0xa4

lr : trace_raw_output_f2fs_direct_IO_enter+0x2c/0xa4

sp : ffffffc0443cbbd0

x29: ffffffc0443cbbf0 x28: ffffff8935b120d0 x27: ffffff8935b12108

x26: ffffff8935b120f0 x25: ffffff8935b12100 x24: ffffff8935b110c0

x23: ffffff8935b10000 x22: ffffff88859a936c x21: ffffff88859a936c

x20: ffffff8935b110c0 x19: ffffff8935b10000 x18: ffffffc03b195060

x17: ffffff8935b11e76 x16: 00000000000000cc x15: ffffffef855c4f2c

x14: 0000000000000001 x13: 000000000000004e x12: ffff0000ffffff00

x11: ffffffef86c350d0 x10: 00000000000010c0 x9 : 000000000fe0002c

x8 : ffffffc04cef3d28 x7 : 7f7f7f7f7f7f7f7f x6 : 0000000002000000

x5 : ffffff8935b11e9a x4 : 0000000000006250 x3 : ffff0a00ffffff04

x2 : 0000000000000002 x1 : ffffffef86a0a31f x0 : ffffff8935b10000

Call trace:

trace_raw_output_f2fs_direct_IO_enter+0x54/0xa4

print_trace_fmt+0x9c/0x138

print_trace_line+0x154/0x254

tracing_read_pipe+0x21c/0x380

vfs_read+0x108/0x3ac

ksys_read+0x7c/0xec

__arm64_sys_read+0x20/0x30

invoke_syscall+0x60/0x150

el0_svc_common.llvm.1237943816091755067+0xb8/0xf8

do_el0_svc+0x28/0xa0

Fix it by copying the required variables for printing and while at

it fix the similar issue at some other places in the same file.