* FAILED: patch "[PATCH] PCI/MSI: Fix UAF in msi_capability_init" failed to apply to 6.1-stable tree
@ 2024-07-01 14:22 gregkh
2024-07-01 16:28 ` Mostafa Saleh
0 siblings, 1 reply; 2+ messages in thread
From: gregkh @ 2024-07-01 14:22 UTC (permalink / raw)
To: smostafa, bhelgaas, tglx; +Cc: stable
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@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@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@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@linutronix.de>
Signed-off-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Bjorn Heelgas <bhelgaas@google.com>
Cc: stable@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;
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: FAILED: patch "[PATCH] PCI/MSI: Fix UAF in msi_capability_init" failed to apply to 6.1-stable tree
2024-07-01 14:22 FAILED: patch "[PATCH] PCI/MSI: Fix UAF in msi_capability_init" failed to apply to 6.1-stable tree gregkh
@ 2024-07-01 16:28 ` Mostafa Saleh
0 siblings, 0 replies; 2+ messages in thread
From: Mostafa Saleh @ 2024-07-01 16:28 UTC (permalink / raw)
To: gregkh; +Cc: bhelgaas, tglx, stable
Hi Greg,
On Mon, Jul 01, 2024 at 04:22:20PM +0200, gregkh@linuxfoundation.org wrote:
>
> 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@vger.kernel.org>.
>
I can’t repro the UAF in 6.1. Looking more, I think the bug was actual
introduced when MSI_COMMON_FLAGS was added with MSI_FLAG_FREE_MSI_DESCS in
commit "a737b7d0e721 (PCI/MSI: Add support for per device MSI[X] domains)"
And not from the freeing logic mentioned in the Fixes, so the first affected
version is 6.2
Thanks,
Mostafa
> 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@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@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@linutronix.de>
> Signed-off-by: Mostafa Saleh <smostafa@google.com>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Cc: Bjorn Heelgas <bhelgaas@google.com>
> Cc: stable@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;
>
^ permalink raw reply [flat|nested] 2+ messages in thread
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2024-07-01 14:22 FAILED: patch "[PATCH] PCI/MSI: Fix UAF in msi_capability_init" failed to apply to 6.1-stable tree gregkh
2024-07-01 16:28 ` Mostafa Saleh
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