When calling cgo.Read, cgo.Write, and cgo.Sendto with a single-block BlockSeq,
the backing slice address was converted to uintptr via Addr(). Because Go's
garbage collector does not recognize uintptr as a live pointer reference, the
underlying backing array could be collected or reused during the CGO call.
This adds runtime.KeepAlive on the BlockSeq arguments after each single-block
CGO call in ReadToBlocks and WriteFromBlocks.
PiperOrigin-RevId: 968029244
Linux skips the mount-level write check when opening a character device, block device, FIFO, or socket, so write-opening /dev/null on a read-only bind mount succeeds.
Mark the remaining FileDescriptions backed by special-file inodes. Also skip overlay copy-up for writable opens of special files; Linux overlayfs applies the same special_file() exception before deciding whether copy-up is required.
Add regression coverage for character devices and FIFOs through read-only bind mounts.
Go map iteration randomness causes network interface enumeration
(getifaddrs, RTM_GETADDR, RTM_GETLINK, /proc/net/*, SIOCGIFCONF)
to return nondeterministic order, breaking applications like
asciidoctor that expect stable ordering across repeated calls.
Since gVisor allocates NIC IDs monotonically (like Linux ifindex),
sorting by NICID is equivalent to registration order. Add
InterfaceIDs() to inet.Stack so all consumer paths iterate in
deterministic ascending-ID order without ad-hoc sorting at each
call site.
Signed-off-by: Tan Yifeng <[email protected]>
- Introduce Credentials.HasRootCapability().
- Rename Credentials.HasCapability() to Credentials.HasSelfCapability().
- Rename Task.HasCapability() to Task.HasSelfCapability().
- Introduce inet.Namespace.HasCapability(ctx).
- CapError(), invoked by unimplemented syscalls' stubs, now checks
against the root userns.
All towards making it less easy to evaluate creds relative to self userns
instead of root userns in the future.
PiperOrigin-RevId: 853942212
linkat(AT_EMPTY_PATH) needs to check for CAP_DAC_READ_SEARCH in the userns in
which the fd was opened, not the userns of the task running linkat().
To get at that userns, vfs.FileDescription now saves a pointer to the creds
at the time of its creation: plumbing these creds in accounts for much of the
diff. This is similar to how `struct file` stores creds in `f_cred` in Linux.
Moreover, since the Linux patch "vfs: relax linkat() AT_EMPTY_PATH..." [1], the
need for this cap is excused if the creds of the calling task are literally
the same as the one stored in the fd.
[1] https://github.com/torvalds/linux/commit/42bd2af5950456d
PiperOrigin-RevId: 853374474
