Subject: CVE-2024-26765: LoongArch: Disable IRQ before init_fn() for nonboot CPUs

From: Greg Kroah-Hartman <[email-masked]>

Description
===========

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

LoongArch: Disable IRQ before init_fn() for nonboot CPUs

Disable IRQ before init_fn() for nonboot CPUs when hotplug, in order to
silence such warnings (and also avoid potential errors due to unexpected
interrupts):

WARNING: CPU: 1 PID: 0 at kernel/rcu/tree.c:4503 rcu_cpu_starting+0x214/0x280
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.6.17+ #1198
pc 90000000048e3334 ra 90000000047bd56c tp 900000010039c000 sp 900000010039fdd0
a0 0000000000000001 a1 0000000000000006 a2 900000000802c040 a3 0000000000000000
a4 0000000000000001 a5 0000000000000004 a6 0000000000000000 a7 90000000048e3f4c
t0 0000000000000001 t1 9000000005c70968 t2 0000000004000000 t3 000000000005e56e
t4 00000000000002e4 t5 0000000000001000 t6 ffffffff80000000 t7 0000000000040000
t8 9000000007931638 u0 0000000000000006 s9 0000000000000004 s0 0000000000000001
s1 9000000006356ac0 s2 9000000007244000 s3 0000000000000001 s4 0000000000000001
s5 900000000636f000 s6 7fffffffffffffff s7 9000000002123940 s8 9000000001ca55f8
   ra: 90000000047bd56c tlb_init+0x24c/0x528
  ERA: 90000000048e3334 rcu_cpu_starting+0x214/0x280
 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE)
 PRMD: 00000000 (PPLV0 -PIE -PWE)
 EUEN: 00000000 (-FPE -SXE -ASXE -BTE)
 ECFG: 00071000 (LIE=12 VS=7)
ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0)
 PRID: 0014c010 (Loongson-64bit, Loongson-3A5000)
CPU: 1 PID: 0 Comm: swapper/1 Not tainted 6.6.17+ #1198
Stack : 0000000000000000 9000000006375000 9000000005b61878 900000010039c000
        900000010039fa30 0000000000000000 900000010039fa38 900000000619a140
        9000000006456888 9000000006456880 900000010039f950 0000000000000001
        0000000000000001 cb0cb028ec7e52e1 0000000002b90000 9000000100348700
        0000000000000000 0000000000000001 ffffffff916d12f1 0000000000000003
        0000000000040000 9000000007930370 0000000002b90000 0000000000000004
        9000000006366000 900000000619a140 0000000000000000 0000000000000004
        0000000000000000 0000000000000009 ffffffffffc681f2 9000000002123940
        9000000001ca55f8 9000000006366000 90000000047a4828 00007ffff057ded8
        00000000000000b0 0000000000000000 0000000000000000 0000000000071000
        ...
Call Trace:
[<90000000047a4828>] show_stack+0x48/0x1a0
[<9000000005b61874>] dump_stack_lvl+0x84/0xcc
[<90000000047f60ac>] __warn+0x8c/0x1e0
[<9000000005b0ab34>] report_bug+0x1b4/0x280
[<9000000005b63110>] do_bp+0x2d0/0x480
[<90000000047a2e20>] handle_bp+0x120/0x1c0
[<90000000048e3334>] rcu_cpu_starting+0x214/0x280
[<90000000047bd568>] tlb_init+0x248/0x528
[<90000000047a4c44>] per_cpu_trap_init+0x124/0x160
[<90000000047a19f4>] cpu_probe+0x494/0xa00
[<90000000047b551c>] start_secondary+0x3c/0xc0
[<9000000005b66134>] smpboot_entry+0x50/0x58

The Linux kernel CVE team has assigned CVE-2024-26765 to this issue.

Affected and fixed versions
===========================

	Fixed in 6.1.80 with commit a262b78dd085
	Fixed in 6.6.19 with commit dffdf7c783ef
	Fixed in 6.7.7 with commit 8bf2ca8c6071
	Fixed in 6.8 with commit 1001db6c42e4

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-26765
will be updated if fixes are backported, please check that for the most
up to date information about this issue.

Affected files
==============

The file(s) affected by this issue are:
	arch/loongarch/kernel/smp.c

Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/a262b78dd085dbe9b3c75dc1d9c4cd102b110b53
	https://git.kernel.org/stable/c/dffdf7c783ef291eef38a5a0037584fd1a7fa464
	https://git.kernel.org/stable/c/8bf2ca8c60712af288b88ba80f8e4df4573d923f
	https://git.kernel.org/stable/c/1001db6c42e4012b55e5ee19405490f23e033b5a