title: powerpc/iommu: Fix the missing iommu_group_put() during platform domain attach
description: In the Linux kernel, the following vulnerability has been resolved:
powerpc/iommu: Fix the missing iommu_group_put() during platform domain attach
The function spapr_tce_platform_iommu_attach_dev() is missing to call
iommu_group_put() when the domain is already set. This refcount leak
shows up with BUG_ON() during DLPAR remove operation as:
KernelBug: Kernel bug in state 'None': kernel BUG at arch/powerpc/platforms/pseries/iommu.c:100!
Oops: Exception in kernel mode, sig: 5 [#1]
LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=8192 NUMA pSeries
<snip>
Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_016) hv:phyp pSeries
NIP:  c0000000000ff4d4 LR: c0000000000ff4cc CTR: 0000000000000000
REGS: c0000013aed5f840 TRAP: 0700   Tainted: G          I         (6.8.0-rc3-autotest-g99bd3cb0d12e)
MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 44002402  XER: 20040000
CFAR: c000000000a0d170 IRQMASK: 0
...
NIP iommu_reconfig_notifier+0x94/0x200
LR  iommu_reconfig_notifier+0x8c/0x200
Call Trace:
iommu_reconfig_notifier+0x8c/0x200 (unreliable)
notifier_call_chain+0xb8/0x19c
blocking_notifier_call_chain+0x64/0x98
of_reconfig_notify+0x44/0xdc
of_detach_node+0x78/0xb0
ofdt_write.part.0+0x86c/0xbb8
proc_reg_write+0xf4/0x150
vfs_write+0xf8/0x488
ksys_write+0x84/0x140
system_call_exception+0x138/0x330
system_call_vectored_common+0x15c/0x2ec
The patch adds the missing iommu_group_put() call.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: a8ca9fc9134c, lessThan: c90fdea9cac9, status: affected, versionType: git
version: a8ca9fc9134c, lessThan: 0846dd77c834, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 6.7, status: affected
version: 0, lessThan: 6.7, status: unaffected, versionType: custom
version: 6.7.6, lessThanOrEqual: 6.7.*, status: unaffected, versionType: custom
version: 6.8, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
