Re: [PATCH v16 08/16] fs, arm64: untag user pointers in copy_mount_options

2019-06-12 Thread Andrey Konovalov
On Tue, Jun 11, 2019 at 4:38 PM Andrey Konovalov wrote: > > On Sat, Jun 8, 2019 at 6:02 AM Kees Cook wrote: > > > > On Mon, Jun 03, 2019 at 06:55:10PM +0200, Andrey Konovalov wrote: > > > This patch is a part of a series that extends arm64 kernel ABI to allow to > > > pass tagged user pointers (w

Re: [PATCH v16 08/16] fs, arm64: untag user pointers in copy_mount_options

2019-06-11 Thread Andrey Konovalov
On Sat, Jun 8, 2019 at 6:02 AM Kees Cook wrote: > > On Mon, Jun 03, 2019 at 06:55:10PM +0200, Andrey Konovalov wrote: > > This patch is a part of a series that extends arm64 kernel ABI to allow to > > pass tagged user pointers (with the top byte set to something else other > > than 0x00) as syscal

Re: [PATCH v16 08/16] fs, arm64: untag user pointers in copy_mount_options

2019-06-07 Thread Kees Cook
On Mon, Jun 03, 2019 at 06:55:10PM +0200, Andrey Konovalov wrote: > This patch is a part of a series that extends arm64 kernel ABI to allow to > pass tagged user pointers (with the top byte set to something else other > than 0x00) as syscall arguments. > > In copy_mount_options a user address is b

[PATCH v16 08/16] fs, arm64: untag user pointers in copy_mount_options

2019-06-03 Thread Andrey Konovalov
This patch is a part of a series that extends arm64 kernel ABI to allow to pass tagged user pointers (with the top byte set to something else other than 0x00) as syscall arguments. In copy_mount_options a user address is being subtracted from TASK_SIZE. If the address is lower than TASK_SIZE, the