911476ef3c
The err_restore_domain flow was accidently inserted into the success path
in commit 1000dccd5d13 ("iommu: Allow IOMMU_RESV_DIRECT to work on
ARM"). It should only happen if iommu_create_device_direct_mappings()
fails. This caused the domains the be wrongly changed and freed whenever
the sysfs is used, resulting in an oops:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 1 PID: 3417 Comm: avocado Not tainted 6.4.0-rc4-next-20230602 #3
Hardware name: Dell Inc. PowerEdge R6515/07PXPY, BIOS 2.3.6 07/06/2021
RIP: 0010:__iommu_attach_device+0xc/0xa0
Code: c0 c3 cc cc cc cc 48 89 f0 c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 41 54 55 48 8b 47 08 <48> 8b 00 48 85 c0 74 74 48 89 f5 e8 64 12 49 00 41 89 c4 85 c0 74
RSP: 0018:ffffabae0220bd48 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff9ac04f70e410 RCX: 0000000000000001
RDX: ffff9ac044db20c0 RSI: ffff9ac044fa50d0 RDI: ffff9ac04f70e410
RBP: ffff9ac044fa50d0 R08: 1000000100209001 R09: 00000000000002dc
R10: 0000000000000000 R11: 0000000000000000 R12: ffff9ac043d54700
R13: ffff9ac043d54700 R14: 0000000000000001 R15: 0000000000000001
FS: 00007f02e30ae000(0000) GS:ffff9afeb2440000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000012afca006 CR4: 0000000000770ee0
PKRU: 55555554
Call Trace:
<TASK>
? __die+0x24/0x70
? page_fault_oops+0x82/0x150
? __iommu_queue_command_sync+0x80/0xc0
? exc_page_fault+0x69/0x150
? asm_exc_page_fault+0x26/0x30
? __iommu_attach_device+0xc/0xa0
? __iommu_attach_device+0x1c/0xa0
__iommu_device_set_domain+0x42/0x80
__iommu_group_set_domain_internal+0x5d/0x160
iommu_setup_default_domain+0x318/0x400
iommu_group_store_type+0xb1/0x200
kernfs_fop_write_iter+0x12f/0x1c0
vfs_write+0x2a2/0x3b0
ksys_write+0x63/0xe0
do_syscall_64+0x3f/0x90
entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7f02e2f14a6f
Reorganize the error flow so that the success branch and error branches
are clearer.
Fixes: 1000dccd5d13 ("iommu: Allow IOMMU_RESV_DIRECT to work on ARM")
Reported-by: Dheeraj Kumar Srivastava <dheerajkumar.srivastava@amd.com>
Tested-by: Vasant Hegde <vasant.hegde@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/0-v1-5bd8cc969d9e+1f1-iommu_set_def_fix_jgg@nvidia.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.