mm/huge_memory: fix vmf_insert_pfn_{pmd, pud}() crash, handle unaligned addresses

Bug #1835348 reported by quanxian
8
This bug affects 1 person
Affects Status Importance Assigned to Milestone
intel
Fix Released
Undecided
Unassigned
linux (Ubuntu)
Incomplete
Undecided
Unassigned

Bug Description

Description
Starting with c6f3c5ee40c1 ("mm/huge_memory.c: fix modifying of page
protection by insert_pfn_pmd()") vmf_insert_pfn_pmd() internally calls
pmdp_set_access_flags(). That helper enforces a pmd aligned @address
argument via VM_BUG_ON() assertion.

Update the implementation to take a 'struct vm_fault' argument directly
and apply the address alignment fixup internally to fix crash signatures
like:

kernel BUG at arch/x86/mm/pgtable.c:515!
invalid opcode: 0000 1 SMP NOPTI
CPU: 51 PID: 43713 Comm: java Tainted: G OE 4.19.35 #1
[..]
RIP: 0010:pmdp_set_access_flags+0x48/0x50
[..]
Call Trace:
vmf_insert_pfn_pmd+0x198/0x350
dax_iomap_fault+0xe82/0x1190
ext4_dax_huge_fault+0x103/0x1f0
? __switch_to_asm+0x40/0x70
__handle_mm_fault+0x3f6/0x1370
? __switch_to_asm+0x34/0x70
? __switch_to_asm+0x40/0x70
handle_mm_fault+0xda/0x200
__do_page_fault+0x249/0x4f0
do_page_fault+0x32/0x110
? page_fault+0x8/0x30
page_fault+0x1e/0x30

Commits:
fce86ff5802b

Target Release:19.10
Target Kernel: 5.2

Revision history for this message
Ubuntu Kernel Bot (ubuntu-kernel-bot) wrote : Missing required logs.

This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:

apport-collect 1835348

and then change the status of the bug to 'Confirmed'.

If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'.

This change has been made by an automated script, maintained by the Ubuntu Kernel Team.

Changed in linux (Ubuntu):
status: New → Incomplete
quanxian (quanxian-wang)
Changed in intel:
status: New → Fix Released
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