rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed

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

rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed

Registering a kprobe on __rcu_irq_enter_check_tick() can cause kernel

stack overflow as shown below. This issue can be reproduced by enabling

CONFIG_NO_HZ_FULL and booting the kernel with argument "nohz_full=",

and then giving the following commands at the shell prompt:

# cd /sys/kernel/tracing/

# echo 'p:mp1 __rcu_irq_enter_check_tick' >> kprobe_events

# echo 1 > events/kprobes/enable

This commit therefore adds __rcu_irq_enter_check_tick() to the kprobes

blacklist using NOKPROBE_SYMBOL().

Insufficient stack space to handle exception!

ESR: 0x00000000f2000004 -- BRK (AArch64)

FAR: 0x0000ffffccf3e510

Task stack: [0xffff80000ad30000..0xffff80000ad38000]

IRQ stack: [0xffff800008050000..0xffff800008058000]

Overflow stack: [0xffff089c36f9f310..0xffff089c36fa0310]

CPU: 5 PID: 190 Comm: bash Not tainted 6.2.0-rc2-00320-g1f5abbd77e2c #19

Hardware name: linux,dummy-virt (DT)

pstate: 400003c5 (nZcv DAIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--)

pc : __rcu_irq_enter_check_tick+0x0/0x1b8

lr : ct_nmi_enter+0x11c/0x138

sp : ffff80000ad30080

x29: ffff80000ad30080 x28: ffff089c82e20000 x27: 0000000000000000

x26: 0000000000000000 x25: ffff089c02a8d100 x24: 0000000000000000

x23: 00000000400003c5 x22: 0000ffffccf3e510 x21: ffff089c36fae148

x20: ffff80000ad30120 x19: ffffa8da8fcce148 x18: 0000000000000000

x17: 0000000000000000 x16: 0000000000000000 x15: ffffa8da8e44ea6c

x14: ffffa8da8e44e968 x13: ffffa8da8e03136c x12: 1fffe113804d6809

x11: ffff6113804d6809 x10: 0000000000000a60 x9 : dfff800000000000

x8 : ffff089c026b404f x7 : 00009eec7fb297f7 x6 : 0000000000000001

x5 : ffff80000ad30120 x4 : dfff800000000000 x3 : ffffa8da8e3016f4

x2 : 0000000000000003 x1 : 0000000000000000 x0 : 0000000000000000

Kernel panic - not syncing: kernel stack overflow

CPU: 5 PID: 190 Comm: bash Not tainted 6.2.0-rc2-00320-g1f5abbd77e2c #19

Hardware name: linux,dummy-virt (DT)

Call trace:

dump_backtrace+0xf8/0x108

show_stack+0x20/0x30

dump_stack_lvl+0x68/0x84

dump_stack+0x1c/0x38

panic+0x214/0x404

add_taint+0x0/0xf8

panic_bad_stack+0x144/0x160

handle_bad_stack+0x38/0x58

__bad_stack+0x78/0x7c

__rcu_irq_enter_check_tick+0x0/0x1b8

arm64_enter_el1_dbg.isra.0+0x14/0x20

el1_dbg+0x2c/0x90

el1h_64_sync_handler+0xcc/0xe8

el1h_64_sync+0x64/0x68

__rcu_irq_enter_check_tick+0x0/0x1b8

arm64_enter_el1_dbg.isra.0+0x14/0x20

el1_dbg+0x2c/0x90

el1h_64_sync_handler+0xcc/0xe8

el1h_64_sync+0x64/0x68

__rcu_irq_enter_check_tick+0x0/0x1b8

arm64_enter_el1_dbg.isra.0+0x14/0x20

el1_dbg+0x2c/0x90

el1h_64_sync_handler+0xcc/0xe8

el1h_64_sync+0x64/0x68

__rcu_irq_enter_check_tick+0x0/0x1b8

[...]

el1_dbg+0x2c/0x90

el1h_64_sync_handler+0xcc/0xe8

el1h_64_sync+0x64/0x68

__rcu_irq_enter_check_tick+0x0/0x1b8

arm64_enter_el1_dbg.isra.0+0x14/0x20

el1_dbg+0x2c/0x90

el1h_64_sync_handler+0xcc/0xe8

el1h_64_sync+0x64/0x68

__rcu_irq_enter_check_tick+0x0/0x1b8

arm64_enter_el1_dbg.isra.0+0x14/0x20

el1_dbg+0x2c/0x90

el1h_64_sync_handler+0xcc/0xe8

el1h_64_sync+0x64/0x68

__rcu_irq_enter_check_tick+0x0/0x1b8

el1_interrupt+0x28/0x60

el1h_64_irq_handler+0x18/0x28

el1h_64_irq+0x64/0x68

__ftrace_set_clr_event_nolock+0x98/0x198

__ftrace_set_clr_event+0x58/0x80

system_enable_write+0x144/0x178

vfs_write+0x174/0x738

ksys_write+0xd0/0x188

__arm64_sys_write+0x4c/0x60

invoke_syscall+0x64/0x180

el0_svc_common.constprop.0+0x84/0x160

do_el0_svc+0x48/0xe8

el0_svc+0x34/0xd0

el0t_64_sync_handler+0xb8/0xc0

el0t_64_sync+0x190/0x194

SMP: stopping secondary CPUs

Kernel Offset: 0x28da86000000 from 0xffff800008000000

PHYS_OFFSET: 0xfffff76600000000

CPU features: 0x00000,01a00100,0000421b

Memory Limit: none