From: Michael Ellerman mpe@ellerman.id.au

[ Upstream commit a986fa57fd81a1430e00b3c6cf8a325d6f894a63 ]

Al reported a possible use-after-free (UAF) in kvm_spapr_tce_attach_iommu_group().

It looks up `stt` from tablefd, but then continues to use it after doing fdput() on the returned fd. After the fdput() the tablefd is free to be closed by another thread. The close calls kvm_spapr_tce_release() and then release_spapr_tce_table() (via call_rcu()) which frees `stt`.

Although there are calls to rcu_read_lock() in kvm_spapr_tce_attach_iommu_group() they are not sufficient to prevent the UAF, because `stt` is used outside the locked regions.

With an artifcial delay after the fdput() and a userspace program which triggers the race, KASAN detects the UAF:

BUG: KASAN: slab-use-after-free in kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm] Read of size 4 at addr c000200027552c30 by task kvm-vfio/2505 CPU: 54 PID: 2505 Comm: kvm-vfio Not tainted 6.10.0-rc3-next-20240612-dirty #1 Hardware name: 8335-GTH POWER9 0x4e1202 opal:skiboot-v6.5.3-35-g1851b2a06 PowerNV Call Trace: dump_stack_lvl+0xb4/0x108 (unreliable) print_report+0x2b4/0x6ec kasan_report+0x118/0x2b0 __asan_load4+0xb8/0xd0 kvm_spapr_tce_attach_iommu_group+0x298/0x720 [kvm] kvm_vfio_set_attr+0x524/0xac0 [kvm] kvm_device_ioctl+0x144/0x240 [kvm] sys_ioctl+0x62c/0x1810 system_call_exception+0x190/0x440 system_call_vectored_common+0x15c/0x2ec ... Freed by task 0: ... kfree+0xec/0x3e0 release_spapr_tce_table+0xd4/0x11c [kvm] rcu_core+0x568/0x16a0 handle_softirqs+0x23c/0x920 do_softirq_own_stack+0x6c/0x90 do_softirq_own_stack+0x58/0x90 __irq_exit_rcu+0x218/0x2d0 irq_exit+0x30/0x80 arch_local_irq_restore+0x128/0x230 arch_local_irq_enable+0x1c/0x30 cpuidle_enter_state+0x134/0x5cc cpuidle_enter+0x6c/0xb0 call_cpuidle+0x7c/0x100 do_idle+0x394/0x410 cpu_startup_entry+0x60/0x70 start_secondary+0x3fc/0x410 start_secondary_prolog+0x10/0x14

Fix it by delaying the fdput() until `stt` is no longer in use, which is effectively the entire function. To keep the patch minimal add a call to fdput() at each of the existing return paths. Future work can convert the function to goto or __cleanup style cleanup.

With the fix in place the test case no longer triggers the UAF.

Reported-by: Al Viro viro@zeniv.linux.org.uk Closes: https://lore.kernel.org/all/20240610024437.GA1464458@ZenIV/ Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://msgid.link/20240614122910.3499489-1-mpe@ellerman.id.au Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/kvm/book3s_64_vio.c | 18 +++++++++++++----- 1 file changed, 13 insertions(+), 5 deletions(-)

diff --git a/arch/powerpc/kvm/book3s_64_vio.c b/arch/powerpc/kvm/book3s_64_vio.c index 40864373ef876..549e33d4ecd62 100644 --- a/arch/powerpc/kvm/book3s_64_vio.c +++ b/arch/powerpc/kvm/book3s_64_vio.c @@ -129,14 +129,16 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd, } rcu_read_unlock();

- fdput(f); - - if (!found) + if (!found) { + fdput(f); return -EINVAL; + }

table_group = iommu_group_get_iommudata(grp); - if (WARN_ON(!table_group)) + if (WARN_ON(!table_group)) { + fdput(f); return -EFAULT; + }

for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) { struct iommu_table *tbltmp = table_group->tables[i]; @@ -157,8 +159,10 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd, break; } } - if (!tbl) + if (!tbl) { + fdput(f); return -EINVAL; + }

rcu_read_lock(); list_for_each_entry_rcu(stit, &stt->iommu_tables, next) { @@ -169,6 +173,7 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd, /* stit is being destroyed */ iommu_tce_table_put(tbl); rcu_read_unlock(); + fdput(f); return -ENOTTY; } /* @@ -176,6 +181,7 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd, * its KVM reference counter and can return. */ rcu_read_unlock(); + fdput(f); return 0; } rcu_read_unlock(); @@ -183,6 +189,7 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd, stit = kzalloc(sizeof(*stit), GFP_KERNEL); if (!stit) { iommu_tce_table_put(tbl); + fdput(f); return -ENOMEM; }

@@ -191,6 +198,7 @@ extern long kvm_spapr_tce_attach_iommu_group(struct kvm *kvm, int tablefd,

list_add_rcu(&stit->next, &stt->iommu_tables);

+ fdput(f); return 0; }

From: Kailang Yang kailang@realtek.com

[ Upstream commit 70794b9563fe011988bcf6a081af9777e63e8d37 ]

If it enter to runtime D3 state, it didn't shutup Headset MIC pin.

Signed-off-by: Kailang Yang kailang@realtek.com Link: https://lore.kernel.org/r/8d86f61e7d6f4a03b311e4eb4e5caaef@realtek.com Signed-off-by: Takashi Iwai tiwai@suse.de Signed-off-by: Sasha Levin sashal@kernel.org --- sound/pci/hda/patch_realtek.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/sound/pci/hda/patch_realtek.c b/sound/pci/hda/patch_realtek.c index 3a7104f72cabd..2723b0f2f0bb9 100644 --- a/sound/pci/hda/patch_realtek.c +++ b/sound/pci/hda/patch_realtek.c @@ -583,10 +583,14 @@ static void alc_shutup_pins(struct hda_codec *codec) switch (codec->core.vendor_id) { case 0x10ec0236: case 0x10ec0256: + case 0x10ec0257: case 0x19e58326: case 0x10ec0283: + case 0x10ec0285: case 0x10ec0286: + case 0x10ec0287: case 0x10ec0288: + case 0x10ec0295: case 0x10ec0298: alc_headset_mic_no_shutup(codec); break;