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Setting invalid value to /sys/devices/system/cpu/cpuX/hotplug/fail
can control `struct cpuhp_step *sp` address, results in the following
global-out-of-bounds read.
Reproducer:
# echo -2 > /sys/devices/system/cpu/cpu0/hotplug/fail
KASAN report:
BUG: KASAN: global-out-of-bounds in write_cpuhp_fail+0x2cd/0x2e0
Read of size 8 at addr ffffffff89734438 by task bash/1941
CPU: 0 PID: 1941 Comm: bash Not tainted 5.2.0-rc6+ #31
Call Trace:
write_cpuhp_fail+0x2cd/0x2e0
dev_attr_store+0x58/0x80
sysfs_kf_write+0x13d/0x1a0
kernfs_fop_write+0x2bc/0x460
vfs_write+0x1e1/0x560
ksys_write+0x126/0x250
do_syscall_64+0xc1/0x390
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f05e4f4c970
The buggy address belongs to the variable:
cpu_hotplug_lock+0x98/0xa0
Memory state around the buggy address:
ffffffff89734300: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
ffffffff89734380: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffff89734400: 00 00 00 00 fa fa fa fa 00 00 00 00 fa fa fa fa
^
ffffffff89734480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
ffffffff89734500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Add a sanity check for the value written from user space.
Fixes: 1db49484f21ed ("smp/hotplug: Hotplug state fail injection")
Signed-off-by: Eiichi Tsukata <devel@etsukata.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: peterz@infradead.org
Link: https://lkml.kernel.org/r/20190627024732.31672-1-devel@etsukata.com
Currently, if the user specifies an unsupported mitigation strategy on the
kernel command line, it will be ignored silently. The code will fall back
to the default strategy, possibly leaving the system more vulnerable than
expected.
This may happen due to e.g. a simple typo, or, for a stable kernel release,
because not all mitigation strategies have been backported.
Inform the user by printing a message.
Fixes: 98af8452945c5565 ("cpu/speculation: Add 'mitigations=' cmdline option")
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20190516070935.22546-1-geert@linux-m68k.org
Pull iommu fix from Joerg Roedel:
"Revert a commit from the previous pile of fixes which causes new
lockdep splats. It is better to revert it for now and work on a better
and more well tested fix"
* tag 'iommu-fix-v5.2-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
Revert "iommu/vt-d: Fix lock inversion between iommu->lock and device_domain_lock"
Pull PCI fix from Bjorn Helgaas:
"If an IOMMU is present, ignore the P2PDMA whitelist we added for v5.2
because we don't yet know how to support P2PDMA in that case (Logan
Gunthorpe)"
* tag 'pci-v5.2-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
PCI/P2PDMA: Ignore root complex whitelist when an IOMMU is present
This reverts commit 7560cc3ca7d9d11555f80c830544e463fcdb28b8.
With 5.2.0-rc5 I can easily trigger this with lockdep and iommu=pt:
======================================================
WARNING: possible circular locking dependency detected
5.2.0-rc5 #78 Not tainted
------------------------------------------------------
swapper/0/1 is trying to acquire lock:
00000000ea2b3beb (&(&iommu->lock)->rlock){+.+.}, at: domain_context_mapping_one+0xa5/0x4e0
but task is already holding lock:
00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #1 (device_domain_lock){....}:
_raw_spin_lock_irqsave+0x3c/0x50
dmar_insert_one_dev_info+0xbb/0x510
domain_add_dev_info+0x50/0x90
dev_prepare_static_identity_mapping+0x30/0x68
intel_iommu_init+0xddd/0x1422
pci_iommu_init+0x16/0x3f
do_one_initcall+0x5d/0x2b4
kernel_init_freeable+0x218/0x2c1
kernel_init+0xa/0x100
ret_from_fork+0x3a/0x50
-> #0 (&(&iommu->lock)->rlock){+.+.}:
lock_acquire+0x9e/0x170
_raw_spin_lock+0x25/0x30
domain_context_mapping_one+0xa5/0x4e0
pci_for_each_dma_alias+0x30/0x140
dmar_insert_one_dev_info+0x3b2/0x510
domain_add_dev_info+0x50/0x90
dev_prepare_static_identity_mapping+0x30/0x68
intel_iommu_init+0xddd/0x1422
pci_iommu_init+0x16/0x3f
do_one_initcall+0x5d/0x2b4
kernel_init_freeable+0x218/0x2c1
kernel_init+0xa/0x100
ret_from_fork+0x3a/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(device_domain_lock);
lock(&(&iommu->lock)->rlock);
lock(device_domain_lock);
lock(&(&iommu->lock)->rlock);
*** DEADLOCK ***
2 locks held by swapper/0/1:
#0: 00000000033eb13d (dmar_global_lock){++++}, at: intel_iommu_init+0x1e0/0x1422
#1: 00000000a681907b (device_domain_lock){....}, at: domain_context_mapping_one+0x8d/0x4e0
stack backtrace:
CPU: 2 PID: 1 Comm: swapper/0 Not tainted 5.2.0-rc5 #78
Hardware name: LENOVO 20KGS35G01/20KGS35G01, BIOS N23ET50W (1.25 ) 06/25/2018
Call Trace:
dump_stack+0x85/0xc0
print_circular_bug.cold.57+0x15c/0x195
__lock_acquire+0x152a/0x1710
lock_acquire+0x9e/0x170
? domain_context_mapping_one+0xa5/0x4e0
_raw_spin_lock+0x25/0x30
? domain_context_mapping_one+0xa5/0x4e0
domain_context_mapping_one+0xa5/0x4e0
? domain_context_mapping_one+0x4e0/0x4e0
pci_for_each_dma_alias+0x30/0x140
dmar_insert_one_dev_info+0x3b2/0x510
domain_add_dev_info+0x50/0x90
dev_prepare_static_identity_mapping+0x30/0x68
intel_iommu_init+0xddd/0x1422
? printk+0x58/0x6f
? lockdep_hardirqs_on+0xf0/0x180
? do_early_param+0x8e/0x8e
? e820__memblock_setup+0x63/0x63
pci_iommu_init+0x16/0x3f
do_one_initcall+0x5d/0x2b4
? do_early_param+0x8e/0x8e
? rcu_read_lock_sched_held+0x55/0x60
? do_early_param+0x8e/0x8e
kernel_init_freeable+0x218/0x2c1
? rest_init+0x230/0x230
kernel_init+0xa/0x100
ret_from_fork+0x3a/0x50
domain_context_mapping_one() is taking device_domain_lock first then
iommu lock, while dmar_insert_one_dev_info() is doing the reverse.
That should be introduced by commit:
7560cc3ca7d9 ("iommu/vt-d: Fix lock inversion between iommu->lock and
device_domain_lock", 2019-05-27)
So far I still cannot figure out how the previous deadlock was
triggered (I cannot find iommu lock taken before calling of
iommu_flush_dev_iotlb()), however I'm pretty sure that that change
should be incomplete at least because it does not fix all the places
so we're still taking the locks in different orders, while reverting
that commit is very clean to me so far that we should always take
device_domain_lock first then the iommu lock.
We can continue to try to find the real culprit mentioned in
7560cc3ca7d9, but for now I think we should revert it to fix current
breakage.
CC: Joerg Roedel <joro@8bytes.org>
CC: Lu Baolu <baolu.lu@linux.intel.com>
CC: dave.jiang@intel.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Tested-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Pull SCSI fixes from James Bottomley:
"Three driver fixes (and one version number update): a suspend hang in
ufs, a qla hard lock on module removal and a qedi panic during
discovery"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: qla2xxx: Fix hardlockup in abort command during driver remove
scsi: ufs: Avoid runtime suspend possibly being blocked forever
scsi: qedi: update driver version to 8.37.0.20
scsi: qedi: Check targetname while finding boot target information
Presently, there is no path to DMA map P2PDMA memory, so if a TLP targeting
this memory hits the root complex and an IOMMU is present, the IOMMU will
reject the transaction, even if the RC would support P2PDMA.
So until the kernel knows to map these DMA addresses in the IOMMU, we
should not enable the whitelist when an IOMMU is present.
Link: https://lore.kernel.org/linux-pci/20190522201252.2997-1-logang@deltatee.com/
Fixes: 0f97da831026 ("PCI/P2PDMA: Allow P2P DMA between any devices under AMD ZEN Root Complex")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Christoph Hellwig <hch@lst.de>
Pull powerpc fixes from Michael Ellerman:
"This is a frustratingly large batch at rc5. Some of these were sent
earlier but were missed by me due to being distracted by other things,
and some took a while to track down due to needing manual bisection on
old hardware. But still we clearly need to improve our testing of KVM,
and of 32-bit, so that we catch these earlier.
Summary: seven fixes, all for bugs introduced this cycle.
- The commit to add KASAN support broke booting on 32-bit SMP
machines, due to a refactoring that moved some setup out of the
secondary CPU path.
- A fix for another 32-bit SMP bug introduced by the fast syscall
entry implementation for 32-bit BOOKE. And a build fix for the same
commit.
- Our change to allow the DAWR to be force enabled on Power9
introduced a bug in KVM, where we clobber r3 leading to a host
crash.
- The same commit also exposed a previously unreachable bug in the
nested KVM handling of DAWR, which could lead to an oops in a
nested host.
- One of the DMA reworks broke the b43legacy WiFi driver on some
people's powermacs, fix it by enabling a 30-bit ZONE_DMA on 32-bit.
- A fix for TLB flushing in KVM introduced a new bug, as it neglected
to also flush the ERAT, this could lead to memory corruption in the
guest.
Thanks to: Aaro Koskinen, Christoph Hellwig, Christophe Leroy, Larry
Finger, Michael Neuling, Suraj Jitindar Singh"
* tag 'powerpc-5.2-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
KVM: PPC: Book3S HV: Invalidate ERAT when flushing guest TLB entries
powerpc: enable a 30-bit ZONE_DMA for 32-bit pmac
KVM: PPC: Book3S HV: Only write DAWR[X] when handling h_set_dawr in real mode
KVM: PPC: Book3S HV: Fix r3 corruption in h_set_dabr()
powerpc/32: fix build failure on book3e with KVM
powerpc/booke: fix fast syscall entry on SMP
powerpc/32s: fix initial setup of segment registers on secondary CPU
[436194.555537] NMI watchdog: Watchdog detected hard LOCKUP on cpu 5
[436194.555558] RIP: 0010:native_queued_spin_lock_slowpath+0x63/0x1e0
[436194.555563] Call Trace:
[436194.555564] _raw_spin_lock_irqsave+0x30/0x40
[436194.555564] qla24xx_async_abort_command+0x29/0xd0 [qla2xxx]
[436194.555565] qla24xx_abort_command+0x208/0x2d0 [qla2xxx]
[436194.555565] __qla2x00_abort_all_cmds+0x16b/0x290 [qla2xxx]
[436194.555565] qla2x00_abort_all_cmds+0x42/0x60 [qla2xxx]
[436194.555566] qla2x00_abort_isp_cleanup+0x2bd/0x3a0 [qla2xxx]
[436194.555566] qla2x00_remove_one+0x1ad/0x360 [qla2xxx]
[436194.555566] pci_device_remove+0x3b/0xb0
Fixes: 219d27d7147e (scsi: qla2xxx: Fix race conditions in the code for aborting SCSI commands)
Cc: stable@vger.kernel.org # 5.2
Signed-off-by: Arun Easi <aeasi@marvell.com>
Signed-off-by: Himanshu Madhani <hmadhani@marvell.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Pull x86 fixes from Thomas Gleixner:
"The accumulated fixes from this and last week:
- Fix vmalloc TLB flush and map range calculations which lead to
stale TLBs, spurious faults and other hard to diagnose issues.
- Use fault_in_pages_writable() for prefaulting the user stack in the
FPU code as it's less fragile than the current solution
- Use the PF_KTHREAD flag when checking for a kernel thread instead
of current->mm as the latter can give the wrong answer due to
use_mm()
- Compute the vmemmap size correctly for KASLR and 5-Level paging.
Otherwise this can end up with a way too small vmemmap area.
- Make KASAN and 5-level paging work again by making sure that all
invalid bits are masked out when computing the P4D offset. This
worked before but got broken recently when the LDT remap area was
moved.
- Prevent a NULL pointer dereference in the resource control code
which can be triggered with certain mount options when the
requested resource is not available.
- Enforce ordering of microcode loading vs. perf initialization on
secondary CPUs. Otherwise perf tries to access a non-existing MSR
as the boot CPU marked it as available.
- Don't stop the resource control group walk early otherwise the
control bitmaps are not updated correctly and become inconsistent.
- Unbreak kgdb by returning 0 on success from
kgdb_arch_set_breakpoint() instead of an error code.
- Add more Icelake CPU model defines so depending changes can be
queued in other trees"
* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/microcode, cpuhotplug: Add a microcode loader CPU hotplug callback
x86/kasan: Fix boot with 5-level paging and KASAN
x86/fpu: Don't use current->mm to check for a kthread
x86/kgdb: Return 0 from kgdb_arch_set_breakpoint()
x86/resctrl: Prevent NULL pointer dereference when local MBM is disabled
x86/resctrl: Don't stop walking closids when a locksetup group is found
x86/fpu: Update kernel's FPU state before using for the fsave header
x86/mm/KASLR: Compute the size of the vmemmap section properly
x86/fpu: Use fault_in_pages_writeable() for pre-faulting
x86/CPU: Add more Icelake model numbers
mm/vmalloc: Avoid rare case of flushing TLB with weird arguments
mm/vmalloc: Fix calculation of direct map addr range
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