When a ZONE_DEVICE private page is freed, the page->mapping field can be
set. If this page is reused as an anonymous page, the previous value can
prevent the page from being inserted into the CPU's anon rmap table.
For example, when migrating a pte_none() page to device memory:
migrate_vma(ops, vma, start, end, src, dst, private)
migrate_vma_collect()
src[] = MIGRATE_PFN_MIGRATE
migrate_vma_prepare()
/* no page to lock or isolate so OK */
migrate_vma_unmap()
/* no page to unmap so OK */
ops->alloc_and_copy()
/* driver allocates ZONE_DEVICE page for dst[] */
migrate_vma_pages()
migrate_vma_insert_page()
page_add_new_anon_rmap()
__page_set_anon_rmap()
/* This check sees the page's stale mapping field */
if (PageAnon(page))
return
/* page->mapping is not updated */
The result is that the migration appears to succeed but a subsequent CPU
fault will be unable to migrate the page back to system memory or worse.
Clear the page->mapping field when freeing the ZONE_DEVICE page so stale
pointer data doesn't affect future page use.
Fixes: b7a523109fb5c9d2d6dd ("mm: don't clear ->mapping in hmm_devmem_free")
Cc: stable(a)vger.kernel.org
Signed-off-by: Ralph Campbell <rcampbell(a)nvidia.com>
Cc: Christoph Hellwig <hch(a)lst.de>
Cc: Dan Williams <dan.j.williams(a)intel.com>
Cc: Andrew Morton <akpm(a)linux-foundation.org>
Cc: Jason Gunthorpe <jgg(a)mellanox.com>
Cc: Logan Gunthorpe <logang(a)deltatee.com>
Cc: Ira Weiny <ira.weiny(a)intel.com>
Cc: Matthew Wilcox <willy(a)infradead.org>
Cc: Mel Gorman <mgorman(a)techsingularity.net>
Cc: Jan Kara <jack(a)suse.cz>
Cc: "Kirill A. Shutemov" <kirill.shutemov(a)linux.intel.com>
Cc: Michal Hocko <mhocko(a)suse.com>
Cc: Andrea Arcangeli <aarcange(a)redhat.com>
Cc: Mike Kravetz <mike.kravetz(a)oracle.com>
Cc: "Jérôme Glisse" <jglisse(a)redhat.com>
---
kernel/memremap.c | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
diff --git a/kernel/memremap.c b/kernel/memremap.c
index bea6f887adad..98d04466dcde 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -408,6 +408,30 @@ void __put_devmap_managed_page(struct page *page)
mem_cgroup_uncharge(page);
+ /*
+ * When a device_private page is freed, the page->mapping field
+ * may still contain a (stale) mapping value. For example, the
+ * lower bits of page->mapping may still identify the page as
+ * an anonymous page. Ultimately, this entire field is just
+ * stale and wrong, and it will cause errors if not cleared.
+ * One example is:
+ *
+ * migrate_vma_pages()
+ * migrate_vma_insert_page()
+ * page_add_new_anon_rmap()
+ * __page_set_anon_rmap()
+ * ...checks page->mapping, via PageAnon(page) call,
+ * and incorrectly concludes that the page is an
+ * anonymous page. Therefore, it incorrectly,
+ * silently fails to set up the new anon rmap.
+ *
+ * For other types of ZONE_DEVICE pages, migration is either
+ * handled differently or not done at all, so there is no need
+ * to clear page->mapping.
+ */
+ if (is_device_private_page(page))
+ page->mapping = NULL;
+
page->pgmap->ops->page_free(page);
} else if (!count)
__put_page(page);
--
2.20.1
From: Wanpeng Li <wanpengli(a)tencent.com>
The idea before commit 240c35a37 was that we have the following FPU states:
userspace (QEMU) guest
---------------------------------------------------------------------------
processor vcpu->arch.guest_fpu
>>> KVM_RUN: kvm_load_guest_fpu
vcpu->arch.user_fpu processor
>>> preempt out
vcpu->arch.user_fpu current->thread.fpu
>>> preempt in
vcpu->arch.user_fpu processor
>>> back to userspace
>>> kvm_put_guest_fpu
processor vcpu->arch.guest_fpu
---------------------------------------------------------------------------
With the new lazy model we want to get the state back to the processor
when schedule in from current->thread.fpu.
Reported-by: Thomas Lambertz <mail(a)thomaslambertz.de>
Reported-by: anthony <antdev66(a)gmail.com>
Tested-by: anthony <antdev66(a)gmail.com>
Cc: Paolo Bonzini <pbonzini(a)redhat.com>
Cc: Radim Krčmář <rkrcmar(a)redhat.com>
Cc: Thomas Lambertz <mail(a)thomaslambertz.de>
Cc: anthony <antdev66(a)gmail.com>
Cc: stable(a)vger.kernel.org
Fixes: 5f409e20b (x86/fpu: Defer FPU state load until return to userspace)
Signed-off-by: Wanpeng Li <wanpengli(a)tencent.com>
---
arch/x86/kvm/x86.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index cf2afdf..bdcd250 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -3306,6 +3306,10 @@ void kvm_arch_vcpu_load(struct kvm_vcpu *vcpu, int cpu)
kvm_x86_ops->vcpu_load(vcpu, cpu);
+ fpregs_assert_state_consistent();
+ if (test_thread_flag(TIF_NEED_FPU_LOAD))
+ switch_fpu_return();
+
/* Apply any externally detected TSC adjustments (due to suspend) */
if (unlikely(vcpu->arch.tsc_offset_adjustment)) {
adjust_tsc_offset_host(vcpu, vcpu->arch.tsc_offset_adjustment);
@@ -7990,9 +7994,7 @@ static int vcpu_enter_guest(struct kvm_vcpu *vcpu)
trace_kvm_entry(vcpu->vcpu_id);
guest_enter_irqoff();
- fpregs_assert_state_consistent();
- if (test_thread_flag(TIF_NEED_FPU_LOAD))
- switch_fpu_return();
+ WARN_ON_ONCE(test_thread_flag(TIF_NEED_FPU_LOAD));
if (unlikely(vcpu->arch.switch_db_regs)) {
set_debugreg(0, 7);
--
2.7.4
From: "Gautham R. Shenoy" <ego(a)linux.vnet.ibm.com>
xive_find_target_in_mask() has the following for(;;) loop which has a
bug when @first == cpumask_first(@mask) and condition 1 fails to hold
for every CPU in @mask. In this case we loop forever in the for-loop.
first = cpu;
for (;;) {
if (cpu_online(cpu) && xive_try_pick_target(cpu)) // condition 1
return cpu;
cpu = cpumask_next(cpu, mask);
if (cpu == first) // condition 2
break;
if (cpu >= nr_cpu_ids) // condition 3
cpu = cpumask_first(mask);
}
This is because, when @first == cpumask_first(@mask), we never hit the
condition 2 (cpu == first) since prior to this check, we would have
executed "cpu = cpumask_next(cpu, mask)" which will set the value of
@cpu to a value greater than @first or to nr_cpus_ids. When this is
coupled with the fact that condition 1 is not met, we will never exit
this loop.
This was discovered by the hard-lockup detector while running LTP test
concurrently with SMT switch tests.
watchdog: CPU 12 detected hard LOCKUP on other CPUs 68
watchdog: CPU 12 TB:85587019220796, last SMP heartbeat TB:85578827223399 (15999ms ago)
watchdog: CPU 68 Hard LOCKUP
watchdog: CPU 68 TB:85587019361273, last heartbeat TB:85576815065016 (19930ms ago)
CPU: 68 PID: 45050 Comm: hxediag Kdump: loaded Not tainted 4.18.0-100.el8.ppc64le #1
NIP: c0000000006f5578 LR: c000000000cba9ec CTR: 0000000000000000
REGS: c000201fff3c7d80 TRAP: 0100 Not tainted (4.18.0-100.el8.ppc64le)
MSR: 9000000002883033 <SF,HV,VEC,VSX,FP,ME,IR,DR,RI,LE> CR: 24028424 XER: 00000000
CFAR: c0000000006f558c IRQMASK: 1
GPR00: c0000000000afc58 c000201c01c43400 c0000000015ce500 c000201cae26ec18
GPR04: 0000000000000800 0000000000000540 0000000000000800 00000000000000f8
GPR08: 0000000000000020 00000000000000a8 0000000080000000 c00800001a1beed8
GPR12: c0000000000b1410 c000201fff7f4c00 0000000000000000 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000540 0000000000000001
GPR20: 0000000000000048 0000000010110000 c00800001a1e3780 c000201cae26ed18
GPR24: 0000000000000000 c000201cae26ed8c 0000000000000001 c000000001116bc0
GPR28: c000000001601ee8 c000000001602494 c000201cae26ec18 000000000000001f
NIP [c0000000006f5578] find_next_bit+0x38/0x90
LR [c000000000cba9ec] cpumask_next+0x2c/0x50
Call Trace:
[c000201c01c43400] [c000201cae26ec18] 0xc000201cae26ec18 (unreliable)
[c000201c01c43420] [c0000000000afc58] xive_find_target_in_mask+0x1b8/0x240
[c000201c01c43470] [c0000000000b0228] xive_pick_irq_target.isra.3+0x168/0x1f0
[c000201c01c435c0] [c0000000000b1470] xive_irq_startup+0x60/0x260
[c000201c01c43640] [c0000000001d8328] __irq_startup+0x58/0xf0
[c000201c01c43670] [c0000000001d844c] irq_startup+0x8c/0x1a0
[c000201c01c436b0] [c0000000001d57b0] __setup_irq+0x9f0/0xa90
[c000201c01c43760] [c0000000001d5aa0] request_threaded_irq+0x140/0x220
[c000201c01c437d0] [c00800001a17b3d4] bnx2x_nic_load+0x188c/0x3040 [bnx2x]
[c000201c01c43950] [c00800001a187c44] bnx2x_self_test+0x1fc/0x1f70 [bnx2x]
[c000201c01c43a90] [c000000000adc748] dev_ethtool+0x11d8/0x2cb0
[c000201c01c43b60] [c000000000b0b61c] dev_ioctl+0x5ac/0xa50
[c000201c01c43bf0] [c000000000a8d4ec] sock_do_ioctl+0xbc/0x1b0
[c000201c01c43c60] [c000000000a8dfb8] sock_ioctl+0x258/0x4f0
[c000201c01c43d20] [c0000000004c9704] do_vfs_ioctl+0xd4/0xa70
[c000201c01c43de0] [c0000000004ca274] sys_ioctl+0xc4/0x160
[c000201c01c43e30] [c00000000000b388] system_call+0x5c/0x70
Instruction dump:
78aad182 54a806be 3920ffff 78a50664 794a1f24 7d294036 7d43502a 7d295039
4182001c 48000034 78a9d182 79291f24 <7d23482a> 2fa90000 409e0020 38a50040
To fix this, move the check for condition 2 after the check for
condition 3, so that we are able to break out of the loop soon after
iterating through all the CPUs in the @mask in the problem case. Use
do..while() to achieve this.
Fixes: 243e25112d06 ("powerpc/xive: Native exploitation of the XIVE
interrupt controller")
Cc: <stable(a)vger.kernel.org> # 4.12+
Reported-by: Indira P. Joga <indira.priya(a)in.ibm.com>
Signed-off-by: Gautham R. Shenoy <ego(a)linux.vnet.ibm.com>
---
arch/powerpc/sysdev/xive/common.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c
index 082c7e1..1cdb395 100644
--- a/arch/powerpc/sysdev/xive/common.c
+++ b/arch/powerpc/sysdev/xive/common.c
@@ -479,7 +479,7 @@ static int xive_find_target_in_mask(const struct cpumask *mask,
* Now go through the entire mask until we find a valid
* target.
*/
- for (;;) {
+ do {
/*
* We re-check online as the fallback case passes us
* an untested affinity mask
@@ -487,12 +487,11 @@ static int xive_find_target_in_mask(const struct cpumask *mask,
if (cpu_online(cpu) && xive_try_pick_target(cpu))
return cpu;
cpu = cpumask_next(cpu, mask);
- if (cpu == first)
- break;
/* Wrap around */
if (cpu >= nr_cpu_ids)
cpu = cpumask_first(mask);
- }
+ } while (cpu != first);
+
return -1;
}
--
1.9.4
From: Yingying Tang <yintang(a)codeaurora.org>
[ Upstream commit 9e7251fa38978b85108c44743e1436d48e8d0d76 ]
tx_stats will be freed and set to NULL before debugfs_sta node is
removed in station disconnetion process. So if read the debugfs_sta
node there may be NULL pointer error. Add check for tx_stats before
use it to resove this issue.
Signed-off-by: Yingying Tang <yintang(a)codeaurora.org>
Signed-off-by: Kalle Valo <kvalo(a)codeaurora.org>
Signed-off-by: Sasha Levin <sashal(a)kernel.org>
---
drivers/net/wireless/ath/ath10k/debugfs_sta.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/net/wireless/ath/ath10k/debugfs_sta.c b/drivers/net/wireless/ath/ath10k/debugfs_sta.c
index c704ae371c4d..42931a669b02 100644
--- a/drivers/net/wireless/ath/ath10k/debugfs_sta.c
+++ b/drivers/net/wireless/ath/ath10k/debugfs_sta.c
@@ -663,6 +663,13 @@ static ssize_t ath10k_dbg_sta_dump_tx_stats(struct file *file,
mutex_lock(&ar->conf_mutex);
+ if (!arsta->tx_stats) {
+ ath10k_warn(ar, "failed to get tx stats");
+ mutex_unlock(&ar->conf_mutex);
+ kfree(buf);
+ return 0;
+ }
+
spin_lock_bh(&ar->data_lock);
for (k = 0; k < ATH10K_STATS_TYPE_MAX; k++) {
for (j = 0; j < ATH10K_COUNTER_TYPE_MAX; j++) {
--
2.20.1
Hmm. I just realized when I saw Sasha's autoselect patches flying by
that the floppy ioctl fixes didn't get marked for stable, but they
probably should be.
There's four commits:
da99466ac243 floppy: fix out-of-bounds read in copy_buffer
9b04609b7840 floppy: fix invalid pointer dereference in drive_name
5635f897ed83 floppy: fix out-of-bounds read in next_valid_format
f3554aeb9912 floppy: fix div-by-zero in setup_format_params
that look like stable material - even if I sincerely hope that the
floppy driver isn't critical for anybody.
I leave it to the stable people to decide if they care. I don't think
the hardware matters any more, but I could imagine that people still
use it for some virtual images and have a floppy device inside a VM
for that reason.
Linus