Commit-ID: 935232ce28dfabff1171e5a7113b2d865fa9ee63 Gitweb: https://git.kernel.org/tip/935232ce28dfabff1171e5a7113b2d865fa9ee63 Author: Joerg Roedel <jroedel@xxxxxxx> AuthorDate: Wed, 18 Jul 2018 11:41:01 +0200 Committer: Thomas Gleixner <tglx@xxxxxxxxxxxxx> CommitDate: Fri, 20 Jul 2018 01:11:43 +0200 x86/mm/pti: Add an overflow check to pti_clone_pmds() The addr counter will overflow if the last PMD of the address space is cloned, resulting in an endless loop. Check for that and bail out of the loop when it happens. Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Tested-by: Pavel Machek <pavel@xxxxxx> Cc: "H . Peter Anvin" <hpa@xxxxxxxxx> Cc: linux-mm@xxxxxxxxx Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Andy Lutomirski <luto@xxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Cc: Juergen Gross <jgross@xxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Jiri Kosina <jkosina@xxxxxxx> Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx> Cc: Brian Gerst <brgerst@xxxxxxxxx> Cc: David Laight <David.Laight@xxxxxxxxxx> Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx> Cc: Eduardo Valentin <eduval@xxxxxxxxxx> Cc: Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> Cc: Will Deacon <will.deacon@xxxxxxx> Cc: aliguori@xxxxxxxxxx Cc: daniel.gruss@xxxxxxxxxxxxxx Cc: hughd@xxxxxxxxxx Cc: keescook@xxxxxxxxxx Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Waiman Long <llong@xxxxxxxxxx> Cc: "David H . Gutteridge" <dhgutteridge@xxxxxxxxxxxx> Cc: joro@xxxxxxxxxx Link: https://lkml.kernel.org/r/1531906876-13451-25-git-send-email-joro@xxxxxxxxxx --- arch/x86/mm/pti.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c index 71fba17c9d7c..79217868dd13 100644 --- a/arch/x86/mm/pti.c +++ b/arch/x86/mm/pti.c @@ -297,6 +297,10 @@ pti_clone_pmds(unsigned long start, unsigned long end, pmdval_t clear) p4d_t *p4d; pud_t *pud; + /* Overflow check */ + if (addr < start) + break; + pgd = pgd_offset_k(addr); if (WARN_ON(pgd_none(*pgd))) return; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
|