Re: [Qemu-devel] [for-2.10 PATCH v3] 9pfs: local: fix fchmodat_nofollow() limitations

2017-08-09 Thread Greg Kurz
On Wed, 9 Aug 2017 11:19:42 -0500 Eric Blake wrote: > On 08/09/2017 11:00 AM, Greg Kurz wrote: > > This function has to ensure it doesn't follow a symlink that could be used > > to escape the virtfs directory. This could be easily achieved if fchmodat() > > on linux honored

Re: [Qemu-devel] [for-2.10 PATCH v3] 9pfs: local: fix fchmodat_nofollow() limitations

2017-08-09 Thread Eric Blake
On 08/09/2017 11:00 AM, Greg Kurz wrote: > This function has to ensure it doesn't follow a symlink that could be used > to escape the virtfs directory. This could be easily achieved if fchmodat() > on linux honored the AT_SYMLINK_NOFOLLOW flag as described in POSIX, but > it doesn't. There was a