cve/published/2024/CVE-2024-26745.mbox - pub/scm/linux/security/vulns - Git at Google

 From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001
 From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
 To: <linux-cve-announce@vger.kernel.org>
 Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
 Subject: CVE-2024-26745: powerpc/pseries/iommu: IOMMU table is not initialized for kdump over SR-IOV

 Description
 ===========

 In the Linux kernel, the following vulnerability has been resolved:

 powerpc/pseries/iommu: IOMMU table is not initialized for kdump over SR-IOV

 When kdump kernel tries to copy dump data over SR-IOV, LPAR panics due
 to NULL pointer exception:

   Kernel attempted to read user page (0) - exploit attempt? (uid: 0)
   BUG: Kernel NULL pointer dereference on read at 0x00000000
   Faulting instruction address: 0xc000000020847ad4
   Oops: Kernel access of bad area, sig: 11 [#1]
   LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
   Modules linked in: mlx5_core(+) vmx_crypto pseries_wdt papr_scm libnvdimm mlxfw tls psample sunrpc fuse overlay squashfs loop
   CPU: 12 PID: 315 Comm: systemd-udevd Not tainted 6.4.0-Test102+ #12
   Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
   NIP:  c000000020847ad4 LR: c00000002083b2dc CTR: 00000000006cd18c
   REGS: c000000029162ca0 TRAP: 0300   Not tainted  (6.4.0-Test102+)
   MSR:  800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE>  CR: 48288244  XER: 00000008
   CFAR: c00000002083b2d8 DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 1
   ...
   NIP _find_next_zero_bit+0x24/0x110
   LR  bitmap_find_next_zero_area_off+0x5c/0xe0
   Call Trace:
     dev_printk_emit+0x38/0x48 (unreliable)
     iommu_area_alloc+0xc4/0x180
     iommu_range_alloc+0x1e8/0x580
     iommu_alloc+0x60/0x130
     iommu_alloc_coherent+0x158/0x2b0
     dma_iommu_alloc_coherent+0x3c/0x50
     dma_alloc_attrs+0x170/0x1f0
     mlx5_cmd_init+0xc0/0x760 [mlx5_core]
     mlx5_function_setup+0xf0/0x510 [mlx5_core]
     mlx5_init_one+0x84/0x210 [mlx5_core]
     probe_one+0x118/0x2c0 [mlx5_core]
     local_pci_probe+0x68/0x110
     pci_call_probe+0x68/0x200
     pci_device_probe+0xbc/0x1a0
     really_probe+0x104/0x540
     __driver_probe_device+0xb4/0x230
     driver_probe_device+0x54/0x130
     __driver_attach+0x158/0x2b0
     bus_for_each_dev+0xa8/0x130
     driver_attach+0x34/0x50
     bus_add_driver+0x16c/0x300
     driver_register+0xa4/0x1b0
     __pci_register_driver+0x68/0x80
     mlx5_init+0xb8/0x100 [mlx5_core]
     do_one_initcall+0x60/0x300
     do_init_module+0x7c/0x2b0

 At the time of LPAR dump, before kexec hands over control to kdump
 kernel, DDWs (Dynamic DMA Windows) are scanned and added to the FDT.
 For the SR-IOV case, default DMA window "ibm,dma-window" is removed from
 the FDT and DDW added, for the device.

 Now, kexec hands over control to the kdump kernel.

 When the kdump kernel initializes, PCI busses are scanned and IOMMU
 group/tables created, in pci_dma_bus_setup_pSeriesLP(). For the SR-IOV
 case, there is no "ibm,dma-window". The original commit: b1fc44eaa9ba,
 fixes the path where memory is pre-mapped (direct mapped) to the DDW.
 When TCEs are direct mapped, there is no need to initialize IOMMU
 tables.

 iommu_table_setparms_lpar() only considers "ibm,dma-window" property
 when initiallizing IOMMU table. In the scenario where TCEs are
 dynamically allocated for SR-IOV, newly created IOMMU table is not
 initialized. Later, when the device driver tries to enter TCEs for the
 SR-IOV device, NULL pointer execption is thrown from iommu_area_alloc().

 The fix is to initialize the IOMMU table with DDW property stored in the
 FDT. There are 2 points to remember:

 	1. For the dedicated adapter, kdump kernel would encounter both
 	   default and DDW in FDT. In this case, DDW property is used to
 	   initialize the IOMMU table.

 	2. A DDW could be direct or dynamic mapped. kdump kernel would
 	   initialize IOMMU table and mark the existing DDW as
 	   "dynamic". This works fine since, at the time of table
 	   initialization, iommu_table_clear() makes some space in the
 	   DDW, for some predefined number of TCEs which are needed for
 	   kdump to succeed.

 The Linux kernel CVE team has assigned CVE-2024-26745 to this issue.


 Affected and fixed versions
 ===========================

 	Issue introduced in 6.0 with commit b1fc44eaa9ba31e28c4125d6b9205a3582b47b5d and fixed in 6.1.81 with commit 7eb95e0af5c9c2e6fad50356eaf32d216d0e7bc3
 	Issue introduced in 6.0 with commit b1fc44eaa9ba31e28c4125d6b9205a3582b47b5d and fixed in 6.6.21 with commit d4d1e4b1513d975961de7bb4f75e450a92d65ebf
 	Issue introduced in 6.0 with commit b1fc44eaa9ba31e28c4125d6b9205a3582b47b5d and fixed in 6.7.9 with commit 5da6d306f315344af1ca2eff4bd9b10b130f0c28
 	Issue introduced in 6.0 with commit b1fc44eaa9ba31e28c4125d6b9205a3582b47b5d and fixed in 6.8 with commit 09a3c1e46142199adcee372a420b024b4fc61051
 	Issue introduced in 5.18.18 with commit b9f08b2649dddd4eb0698cb428b173bb01dd2fc5
 	Issue introduced in 5.19.2 with commit 58942f672c6d04b6a3cd7866cb459671df881538

 Please see https://www.kernel.org for a full list of currently supported
 kernel versions by the kernel community.

 Unaffected versions might change over time as fixes are backported to
 older supported kernel versions.  The official CVE entry at
 	https://cve.org/CVERecord/?id=CVE-2024-26745
 will be updated if fixes are backported, please check that for the most
 up to date information about this issue.


 Affected files
 ==============

 The file(s) affected by this issue are:
 	arch/powerpc/platforms/pseries/iommu.c


 Mitigation
 ==========

 The Linux kernel CVE team recommends that you update to the latest
 stable kernel version for this, and many other bugfixes.  Individual
 changes are never tested alone, but rather are part of a larger kernel
 release.  Cherry-picking individual commits is not recommended or
 supported by the Linux kernel community at all.  If however, updating to
 the latest release is impossible, the individual changes to resolve this
 issue can be found at these commits:
 	https://git.kernel.org/stable/c/7eb95e0af5c9c2e6fad50356eaf32d216d0e7bc3
 	https://git.kernel.org/stable/c/d4d1e4b1513d975961de7bb4f75e450a92d65ebf
 	https://git.kernel.org/stable/c/5da6d306f315344af1ca2eff4bd9b10b130f0c28
 	https://git.kernel.org/stable/c/09a3c1e46142199adcee372a420b024b4fc61051
	From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001
	From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
	To: <linux-cve-announce@vger.kernel.org>
	Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org>
	Subject: CVE-2024-26745: powerpc/pseries/iommu: IOMMU table is not initialized for kdump over SR-IOV

	Description
	===========

	In the Linux kernel, the following vulnerability has been resolved:

	powerpc/pseries/iommu: IOMMU table is not initialized for kdump over SR-IOV

	When kdump kernel tries to copy dump data over SR-IOV, LPAR panics due
	to NULL pointer exception:

	Kernel attempted to read user page (0) - exploit attempt? (uid: 0)
	BUG: Kernel NULL pointer dereference on read at 0x00000000
	Faulting instruction address: 0xc000000020847ad4
	Oops: Kernel access of bad area, sig: 11 [#1]
	LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
	Modules linked in: mlx5_core(+) vmx_crypto pseries_wdt papr_scm libnvdimm mlxfw tls psample sunrpc fuse overlay squashfs loop
	CPU: 12 PID: 315 Comm: systemd-udevd Not tainted 6.4.0-Test102+ #12
	Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
	NIP: c000000020847ad4 LR: c00000002083b2dc CTR: 00000000006cd18c
	REGS: c000000029162ca0 TRAP: 0300 Not tainted (6.4.0-Test102+)
	MSR: 800000000280b033 <SF,VEC,VSX,EE,FP,ME,IR,DR,RI,LE> CR: 48288244 XER: 00000008
	CFAR: c00000002083b2d8 DAR: 0000000000000000 DSISR: 40000000 IRQMASK: 1
	...
	NIP _find_next_zero_bit+0x24/0x110
	LR bitmap_find_next_zero_area_off+0x5c/0xe0
	Call Trace:
	dev_printk_emit+0x38/0x48 (unreliable)
	iommu_area_alloc+0xc4/0x180
	iommu_range_alloc+0x1e8/0x580
	iommu_alloc+0x60/0x130
	iommu_alloc_coherent+0x158/0x2b0
	dma_iommu_alloc_coherent+0x3c/0x50
	dma_alloc_attrs+0x170/0x1f0
	mlx5_cmd_init+0xc0/0x760 [mlx5_core]
	mlx5_function_setup+0xf0/0x510 [mlx5_core]
	mlx5_init_one+0x84/0x210 [mlx5_core]
	probe_one+0x118/0x2c0 [mlx5_core]
	local_pci_probe+0x68/0x110
	pci_call_probe+0x68/0x200
	pci_device_probe+0xbc/0x1a0
	really_probe+0x104/0x540
	__driver_probe_device+0xb4/0x230
	driver_probe_device+0x54/0x130
	__driver_attach+0x158/0x2b0
	bus_for_each_dev+0xa8/0x130
	driver_attach+0x34/0x50
	bus_add_driver+0x16c/0x300
	driver_register+0xa4/0x1b0
	__pci_register_driver+0x68/0x80
	mlx5_init+0xb8/0x100 [mlx5_core]
	do_one_initcall+0x60/0x300
	do_init_module+0x7c/0x2b0

	At the time of LPAR dump, before kexec hands over control to kdump
	kernel, DDWs (Dynamic DMA Windows) are scanned and added to the FDT.
	For the SR-IOV case, default DMA window "ibm,dma-window" is removed from
	the FDT and DDW added, for the device.

	Now, kexec hands over control to the kdump kernel.

	When the kdump kernel initializes, PCI busses are scanned and IOMMU
	group/tables created, in pci_dma_bus_setup_pSeriesLP(). For the SR-IOV
	case, there is no "ibm,dma-window". The original commit: b1fc44eaa9ba,
	fixes the path where memory is pre-mapped (direct mapped) to the DDW.
	When TCEs are direct mapped, there is no need to initialize IOMMU
	tables.

	iommu_table_setparms_lpar() only considers "ibm,dma-window" property
	when initiallizing IOMMU table. In the scenario where TCEs are
	dynamically allocated for SR-IOV, newly created IOMMU table is not
	initialized. Later, when the device driver tries to enter TCEs for the
	SR-IOV device, NULL pointer execption is thrown from iommu_area_alloc().

	The fix is to initialize the IOMMU table with DDW property stored in the
	FDT. There are 2 points to remember:

	1. For the dedicated adapter, kdump kernel would encounter both
	default and DDW in FDT. In this case, DDW property is used to
	initialize the IOMMU table.

	2. A DDW could be direct or dynamic mapped. kdump kernel would
	initialize IOMMU table and mark the existing DDW as
	"dynamic". This works fine since, at the time of table
	initialization, iommu_table_clear() makes some space in the
	DDW, for some predefined number of TCEs which are needed for
	kdump to succeed.

	The Linux kernel CVE team has assigned CVE-2024-26745 to this issue.


	Affected and fixed versions
	===========================

	Issue introduced in 6.0 with commit b1fc44eaa9ba31e28c4125d6b9205a3582b47b5d and fixed in 6.1.81 with commit 7eb95e0af5c9c2e6fad50356eaf32d216d0e7bc3
	Issue introduced in 6.0 with commit b1fc44eaa9ba31e28c4125d6b9205a3582b47b5d and fixed in 6.6.21 with commit d4d1e4b1513d975961de7bb4f75e450a92d65ebf
	Issue introduced in 6.0 with commit b1fc44eaa9ba31e28c4125d6b9205a3582b47b5d and fixed in 6.7.9 with commit 5da6d306f315344af1ca2eff4bd9b10b130f0c28
	Issue introduced in 6.0 with commit b1fc44eaa9ba31e28c4125d6b9205a3582b47b5d and fixed in 6.8 with commit 09a3c1e46142199adcee372a420b024b4fc61051
	Issue introduced in 5.18.18 with commit b9f08b2649dddd4eb0698cb428b173bb01dd2fc5
	Issue introduced in 5.19.2 with commit 58942f672c6d04b6a3cd7866cb459671df881538

	Please see https://www.kernel.org for a full list of currently supported
	kernel versions by the kernel community.

	Unaffected versions might change over time as fixes are backported to
	older supported kernel versions. The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2024-26745
	will be updated if fixes are backported, please check that for the most
	up to date information about this issue.


	Affected files
	==============

	The file(s) affected by this issue are:
	arch/powerpc/platforms/pseries/iommu.c


	Mitigation
	==========

	The Linux kernel CVE team recommends that you update to the latest
	stable kernel version for this, and many other bugfixes. Individual
	changes are never tested alone, but rather are part of a larger kernel
	release. Cherry-picking individual commits is not recommended or
	supported by the Linux kernel community at all. If however, updating to
	the latest release is impossible, the individual changes to resolve this
	issue can be found at these commits:
	https://git.kernel.org/stable/c/7eb95e0af5c9c2e6fad50356eaf32d216d0e7bc3
	https://git.kernel.org/stable/c/d4d1e4b1513d975961de7bb4f75e450a92d65ebf
	https://git.kernel.org/stable/c/5da6d306f315344af1ca2eff4bd9b10b130f0c28
	https://git.kernel.org/stable/c/09a3c1e46142199adcee372a420b024b4fc61051