Re: [PATCH v2] acpi: fix a potential inconsistency caused by double-fetch

On Tue, Jan 15, 2019 at 7:05 AM Kangjie Lu wrote: > > > > On Mon, Jan 14, 2019 at 5:15 AM Rafael J. Wysocki wrote: >> >> On Wed, Jan 9, 2019 at 9:14 AM Kangjie Lu wrote: >> > >> > "user_buf->length" is in user space, and copied in twice. The second >> > copy is after it passes the security

Re: [PATCH v2] acpi: fix a potential inconsistency caused by double-fetch

On Wed, Jan 9, 2019 at 9:14 AM Kangjie Lu wrote: > > "user_buf->length" is in user space, and copied in twice. The second > copy is after it passes the security check. If a user program races to > change user_buf->length in user space, the data fetched in the second > copy may invalidate the

[PATCH v2] acpi: fix a potential inconsistency caused by double-fetch

"user_buf->length" is in user space, and copied in twice. The second copy is after it passes the security check. If a user program races to change user_buf->length in user space, the data fetched in the second copy may invalidate the security check. The fix avoids the double-fetch issue by using