diff options
| author | Aleksandr Nogikh <nogikh@google.com> | 2022-01-12 14:40:51 +0000 |
|---|---|---|
| committer | Aleksandr Nogikh <wp32pw@gmail.com> | 2022-01-13 17:03:14 +0100 |
| commit | d6f3385b1a3f2fba8e14d6794bece1dcdd9e479e (patch) | |
| tree | c3163643d321b913450df84f41731b71d5874243 /sys/targets | |
| parent | 6baa7baec59a790c452b0b1c97447475eb6c1afe (diff) | |
all: add syz_clone() and syz_clone3() pseudo calls
As was pointed out in #2921, the current approach of limiting the number
of pids per process does not work on all Linux-based kernels.
We could just treat fork, clone and clone3 in a special way (e.g. exit
on a zero return). However, in that case we also need to sanitize the
arguments for clone and clone3 - if CLONE_VM is passed and stack is 0,
the forked child processes (threads) will become nearly unindentifiable
and will corrupt syz-executor's memory. While we could sanitize clone's
arguments, we cannot do so for clone3 - nothing can guarantee that they
will not be changed concurrently.
Instead of calling those syscalls directly, introduce a special pseudo
syscall syz_clone3. It copies and sanitizes the arguments and then
executes clone3 (or fork, if we're on an older kernel) in such a way so
as to prevent fork bombs from happening.
Also introduce syz_clone() to still be able to fuzz it on older systems.
Diffstat (limited to 'sys/targets')
| -rw-r--r-- | sys/targets/targets.go | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/sys/targets/targets.go b/sys/targets/targets.go index a975ad27a..7255f7963 100644 --- a/sys/targets/targets.go +++ b/sys/targets/targets.go @@ -458,9 +458,11 @@ var oses = map[string]osCommon{ ExecutorUsesForkServer: true, KernelObject: "vmlinux", PseudoSyscallDeps: map[string][]string{ - "syz_read_part_table": []string{"memfd_create"}, - "syz_mount_image": []string{"memfd_create"}, - "syz_io_uring_setup": []string{"io_uring_setup"}, + "syz_read_part_table": {"memfd_create"}, + "syz_mount_image": {"memfd_create"}, + "syz_io_uring_setup": {"io_uring_setup"}, + "syz_clone3": {"clone3", "exit"}, + "syz_clone": {"clone", "exit"}, }, cflags: []string{"-static-pie"}, }, |