The patch below does not apply to the 6.1-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable(a)vger.kernel.org>.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 9eee5330656bf92f51cb1f09b2dc9f8cf975b3d1
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2024070120-undergo-stipulate-9aae@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..
Possible dependencies:
9eee5330656b ("PCI/MSI: Fix UAF in msi_capability_init")
b12d0bec385b ("PCI/MSI: Move pci_disable_msi() to api.c")
c93fd5266cff ("PCI/MSI: Move mask and unmask helpers to msi.h")
a474d3fbe287 ("PCI/MSI: Get rid of PCI_MSI_IRQ_DOMAIN")
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 9eee5330656bf92f51cb1f09b2dc9f8cf975b3d1 Mon Sep 17 00:00:00 2001
From: Mostafa Saleh <smostafa(a)google.com>
Date: Mon, 24 Jun 2024 20:37:28 +0000
Subject: [PATCH] PCI/MSI: Fix UAF in msi_capability_init
KFENCE reports the following UAF:
BUG: KFENCE: use-after-free read in __pci_enable_msi_range+0x2c0/0x488
Use-after-free read at 0x0000000024629571 (in kfence-#12):
__pci_enable_msi_range+0x2c0/0x488
pci_alloc_irq_vectors_affinity+0xec/0x14c
pci_alloc_irq_vectors+0x18/0x28
kfence-#12: 0x0000000008614900-0x00000000e06c228d, size=104, cache=kmalloc-128
allocated by task 81 on cpu 7 at 10.808142s:
__kmem_cache_alloc_node+0x1f0/0x2bc
kmalloc_trace+0x44/0x138
msi_alloc_desc+0x3c/0x9c
msi_domain_insert_msi_desc+0x30/0x78
msi_setup_msi_desc+0x13c/0x184
__pci_enable_msi_range+0x258/0x488
pci_alloc_irq_vectors_affinity+0xec/0x14c
pci_alloc_irq_vectors+0x18/0x28
freed by task 81 on cpu 7 at 10.811436s:
msi_domain_free_descs+0xd4/0x10c
msi_domain_free_locked.part.0+0xc0/0x1d8
msi_domain_alloc_irqs_all_locked+0xb4/0xbc
pci_msi_setup_msi_irqs+0x30/0x4c
__pci_enable_msi_range+0x2a8/0x488
pci_alloc_irq_vectors_affinity+0xec/0x14c
pci_alloc_irq_vectors+0x18/0x28
Descriptor allocation done in:
__pci_enable_msi_range
msi_capability_init
msi_setup_msi_desc
msi_insert_msi_desc
msi_domain_insert_msi_desc
msi_alloc_desc
...
Freed in case of failure in __msi_domain_alloc_locked()
__pci_enable_msi_range
msi_capability_init
pci_msi_setup_msi_irqs
msi_domain_alloc_irqs_all_locked
msi_domain_alloc_locked
__msi_domain_alloc_locked => fails
msi_domain_free_locked
...
That failure propagates back to pci_msi_setup_msi_irqs() in
msi_capability_init() which accesses the descriptor for unmasking in the
error exit path.
Cure it by copying the descriptor and using the copy for the error exit path
unmask operation.
[ tglx: Massaged change log ]
Fixes: bf6e054e0e3f ("genirq/msi: Provide msi_device_populate/destroy_sysfs()")
Suggested-by: Thomas Gleixner <tglx(a)linutronix.de>
Signed-off-by: Mostafa Saleh <smostafa(a)google.com>
Signed-off-by: Thomas Gleixner <tglx(a)linutronix.de>
Cc: Bjorn Heelgas <bhelgaas(a)google.com>
Cc: stable(a)vger.kernel.org
Link: https://lore.kernel.org/r/20240624203729.1094506-1-smostafa@google.com
diff --git a/drivers/pci/msi/msi.c b/drivers/pci/msi/msi.c
index c5625dd9bf49..3a45879d85db 100644
--- a/drivers/pci/msi/msi.c
+++ b/drivers/pci/msi/msi.c
@@ -352,7 +352,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
struct irq_affinity *affd)
{
struct irq_affinity_desc *masks = NULL;
- struct msi_desc *entry;
+ struct msi_desc *entry, desc;
int ret;
/* Reject multi-MSI early on irq domain enabled architectures */
@@ -377,6 +377,12 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
/* All MSIs are unmasked by default; mask them all */
entry = msi_first_desc(&dev->dev, MSI_DESC_ALL);
pci_msi_mask(entry, msi_multi_mask(entry));
+ /*
+ * Copy the MSI descriptor for the error path because
+ * pci_msi_setup_msi_irqs() will free it for the hierarchical
+ * interrupt domain case.
+ */
+ memcpy(&desc, entry, sizeof(desc));
/* Configure MSI capability structure */
ret = pci_msi_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
@@ -396,7 +402,7 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
goto unlock;
err:
- pci_msi_unmask(entry, msi_multi_mask(entry));
+ pci_msi_unmask(&desc, msi_multi_mask(&desc));
pci_free_msi_irqs(dev);
fail:
dev->msi_enabled = 0;
Commit f740106aedd3 (HID: apple: remove unused members from struct apple_sc_backlight) in Linus’ tree imo should be back ported to:
1. Linux 6.6
2. Linux 6.1
since there hasn't been any change to the backlight code in the driver ever since it has been upstreamed. So it should be safe to remove the unused members from struct apple_sc_backlight