diff options
| author | Dan Williams | 2016-08-25 15:17:14 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2016-08-26 17:39:35 -0700 |
| commit | d0e5845561c238619de9f5b77e0d763f4c331ca5 (patch) | |
| tree | 53fc8b53711bead1fd55588bc3b6fd812e4f195f | |
| parent | 088bf2ff5d12e2e32ee52a4024fec26e582f44d3 (diff) | |
dax: fix device-dax region base
The data offset for a dax region needs to account for a reservation in
the resource range. Otherwise, device-dax is allowing mappings directly
into the memmap or device-info-block area with crash signatures like the
following:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: get_zone_device_page+0x11/0x30
Call Trace:
follow_devmap_pmd+0x298/0x2c0
follow_page_mask+0x275/0x530
__get_user_pages+0xe3/0x750
__gfn_to_pfn_memslot+0x1b2/0x450 [kvm]
tdp_page_fault+0x130/0x280 [kvm]
kvm_mmu_page_fault+0x5f/0xf0 [kvm]
handle_ept_violation+0x94/0x180 [kvm_intel]
vmx_handle_exit+0x1d3/0x1440 [kvm_intel]
kvm_arch_vcpu_ioctl_run+0x81d/0x16a0 [kvm]
kvm_vcpu_ioctl+0x33c/0x620 [kvm]
do_vfs_ioctl+0xa2/0x5d0
SyS_ioctl+0x79/0x90
entry_SYSCALL_64_fastpath+0x1a/0xa4
Fixes: ab68f2622136 ("/dev/dax, pmem: direct access to persistent memory")
Link: http://lkml.kernel.org/r/147205536732.1606.8994275381938837346.stgit@dwillia2-desk3.amr.corp.intel.com
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reported-by: Abhilash Kumar Mulumudi <m.abhilash-kumar@hpe.com>
Reported-by: Toshi Kani <toshi.kani@hpe.com>
Tested-by: Toshi Kani <toshi.kani@hpe.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | drivers/dax/pmem.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/dax/pmem.c b/drivers/dax/pmem.c index dfb168568af1..1f01e98c83c7 100644 --- a/drivers/dax/pmem.c +++ b/drivers/dax/pmem.c @@ -116,6 +116,9 @@ static int dax_pmem_probe(struct device *dev) if (rc) return rc; + /* adjust the dax_region resource to the start of data */ + res.start += le64_to_cpu(pfn_sb->dataoff); + nd_region = to_nd_region(dev->parent); dax_region = alloc_dax_region(dev, nd_region->id, &res, le32_to_cpu(pfn_sb->align), addr, PFN_DEV|PFN_MAP); |