mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-28 20:02:17 +00:00
x86/mm/pti: Handle unaligned address gracefully in pti_clone_pagetable()
pti_clone_pmds() assumes that the supplied address is either: - properly PUD/PMD aligned or - the address is actually mapped which means that independently of the mapping level (PUD/PMD/PTE) the next higher mapping exists. If that's not the case the unaligned address can be incremented by PUD or PMD size incorrectly. All callers supply mapped and/or aligned addresses, but for the sake of robustness it's better to handle that case properly and to emit a warning. [ tglx: Rewrote changelog and added WARN_ON_ONCE() ] Signed-off-by: Song Liu <songliubraving@fb.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1908282352470.1938@nanos.tec.linutronix.de
This commit is contained in:
parent
a55aa89aab
commit
825d0b73cd
1 changed files with 4 additions and 2 deletions
|
@ -330,13 +330,15 @@ pti_clone_pgtable(unsigned long start, unsigned long end,
|
|||
|
||||
pud = pud_offset(p4d, addr);
|
||||
if (pud_none(*pud)) {
|
||||
addr += PUD_SIZE;
|
||||
WARN_ON_ONCE(addr & ~PUD_MASK);
|
||||
addr = round_up(addr + 1, PUD_SIZE);
|
||||
continue;
|
||||
}
|
||||
|
||||
pmd = pmd_offset(pud, addr);
|
||||
if (pmd_none(*pmd)) {
|
||||
addr += PMD_SIZE;
|
||||
WARN_ON_ONCE(addr & ~PMD_MASK);
|
||||
addr = round_up(addr + 1, PMD_SIZE);
|
||||
continue;
|
||||
}
|
||||
|
||||
|
|
Loading…
Reference in a new issue