Wind River Support Network

Description

In the Linux kernel, the following vulnerability has been resolved:EOL][EOL]tracing/eprobes: Do not allow eprobes to use $stack, or % for regs[EOL][EOL]While playing with event probes (eprobes), I tried to see what would[EOL]happen if I attempted to retrieve the instruction pointer (%rip) knowing[EOL]that event probes do not use pt_regs. The result was:[EOL][EOL] BUG: kernel NULL pointer dereference, address: 0000000000000024[EOL] #PF: supervisor read access in kernel mode[EOL] #PF: error_code(0x0000) - not-present page[EOL] PGD 0 P4D 0[EOL] Oops: 0000 [#1] PREEMPT SMP PTI[EOL] CPU: 1 PID: 1847 Comm: trace-cmd Not tainted 5.19.0-rc5-test+ #309[EOL] Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01[EOL]v03.03 07/14/2016[EOL] RIP: 0010:get_event_field.isra.0+0x0/0x50[EOL] Code: ff 48 c7 c7 c0 8f 74 a1 e8 3d 8b f5 ff e8 88 09 f6 ff 4c 89 e7 e8[EOL]50 6a 13 00 48 89 ef 5b 5d 41 5c 41 5d e9 42 6a 13 00 66 90 <48> 63 47 24[EOL]8b 57 2c 48 01 c6 8b 47 28 83 f8 02 74 0e 83 f8 04 74[EOL] RSP: 0018:ffff916c394bbaf0 EFLAGS: 00010086[EOL] RAX: ffff916c854041d8 RBX: ffff916c8d9fbf50 RCX: ffff916c255d2000[EOL] RDX: 0000000000000000 RSI: ffff916c255d2008 RDI: 0000000000000000[EOL] RBP: 0000000000000000 R08: ffff916c3a2a0c08 R09: ffff916c394bbda8[EOL] R10: 0000000000000000 R11: 0000000000000000 R12: ffff916c854041d8[EOL] R13: ffff916c854041b0 R14: 0000000000000000 R15: 0000000000000000[EOL] FS:  0000000000000000(0000) GS:ffff916c9ea40000(0000)[EOL]knlGS:0000000000000000[EOL] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033[EOL] CR2: 0000000000000024 CR3: 000000011b60a002 CR4: 00000000001706e0[EOL] Call Trace:[EOL]  <TASK>[EOL]  get_eprobe_size+0xb4/0x640[EOL]  ? __mod_node_page_state+0x72/0xc0[EOL]  __eprobe_trace_func+0x59/0x1a0[EOL]  ? __mod_lruvec_page_state+0xaa/0x1b0[EOL]  ? page_remove_file_rmap+0x14/0x230[EOL]  ? page_remove_rmap+0xda/0x170[EOL]  event_triggers_call+0x52/0xe0[EOL]  trace_event_buffer_commit+0x18f/0x240[EOL]  trace_event_raw_event_sched_wakeup_template+0x7a/0xb0[EOL]  try_to_wake_up+0x260/0x4c0[EOL]  __wake_up_common+0x80/0x180[EOL]  __wake_up_common_lock+0x7c/0xc0[EOL]  do_notify_parent+0x1c9/0x2a0[EOL]  exit_notify+0x1a9/0x220[EOL]  do_exit+0x2ba/0x450[EOL]  do_group_exit+0x2d/0x90[EOL]  __x64_sys_exit_group+0x14/0x20[EOL]  do_syscall_64+0x3b/0x90[EOL]  entry_SYSCALL_64_after_hwframe+0x46/0xb0[EOL][EOL]Obviously this is not the desired result.[EOL][EOL]Move the testing for TPARG_FL_TPOINT which is only used for event probes[EOL]to the top of the "$" variable check, as all the other variables are not[EOL]used for event probes. Also add a check in the register parsing "%" to[EOL]fail if an event probe is used.

CREATE(Triage):(User=lchen-cn) [CVE-2022-50078 (https://nvd.nist.gov/vuln/detail/CVE-2022-50078)