diff options
| author | Aleksandr Nogikh <nogikh@google.com> | 2024-03-06 14:47:02 +0100 |
|---|---|---|
| committer | Aleksandr Nogikh <nogikh@google.com> | 2024-03-13 10:31:21 +0000 |
| commit | 20d042025bd8e1f91bb1fec20ae1509a08bfa4ef (patch) | |
| tree | e8a3dcb48db65376fdf865480ca5d043f4c7bdcc | |
| parent | 76713834e4ab721bc6265c89203ee171152cc017 (diff) | |
sys/linux: clone args before mutation
Not cloning the argument results in replaceArg() replacing a union
argument with itself, which may lead to inconsistent resource
references.
Add an assertion to detect such cases in the future.
| -rw-r--r-- | prog/clone.go | 4 | ||||
| -rw-r--r-- | prog/prog.go | 3 | ||||
| -rw-r--r-- | sys/linux/init_iptables.go | 4 | ||||
| -rw-r--r-- | sys/linux/init_vusb.go | 4 |
4 files changed, 11 insertions, 4 deletions
diff --git a/prog/clone.go b/prog/clone.go index 029cf94c4..4523be0eb 100644 --- a/prog/clone.go +++ b/prog/clone.go @@ -39,6 +39,10 @@ func cloneCall(c *Call, newargs map[*ResultArg]*ResultArg) *Call { return c1 } +func CloneArg(arg Arg) Arg { + return clone(arg, nil) +} + func clone(arg Arg, newargs map[*ResultArg]*ResultArg) Arg { var arg1 Arg switch a := arg.(type) { diff --git a/prog/prog.go b/prog/prog.go index f93293b64..da6f158bc 100644 --- a/prog/prog.go +++ b/prog/prog.go @@ -354,6 +354,9 @@ func (p *Prog) insertBefore(c *Call, calls []*Call) { // replaceArg replaces arg with arg1 in a program. func replaceArg(arg, arg1 Arg) { + if arg == arg1 { + panic("replacing an argument with itself") + } switch a := arg.(type) { case *ConstArg: *a = *arg1.(*ConstArg) diff --git a/sys/linux/init_iptables.go b/sys/linux/init_iptables.go index 7e96662fb..95825d33c 100644 --- a/sys/linux/init_iptables.go +++ b/sys/linux/init_iptables.go @@ -31,7 +31,7 @@ func (arch *arch) generateNetfilterTable(g *prog.Gen, typ prog.Type, dir prog.Di } else { // TODO(dvyukov): try to restore original hook order after mutation // instead of assigning brand new offsets. - arg = old + arg = prog.CloneArg(old) calls = g.MutateArg(arg) } var tableArg *prog.GroupArg @@ -113,7 +113,7 @@ func (arch *arch) generateEbtables(g *prog.Gen, typ prog.Type, dir prog.Dir, old } else { // TODO(dvyukov): try to restore original hook order after mutation // instead of assigning brand new offsets. - arg = old + arg = prog.CloneArg(old) calls = g.MutateArg(arg) } if g.Target().ArgContainsAny(arg) { diff --git a/sys/linux/init_vusb.go b/sys/linux/init_vusb.go index 5e4244f6e..ca645bf45 100644 --- a/sys/linux/init_vusb.go +++ b/sys/linux/init_vusb.go @@ -55,7 +55,7 @@ func (arch *arch) generateUsbDeviceDescriptor(g *prog.Gen, typ0 prog.Type, dir p if old == nil { arg = g.GenerateSpecialArg(typ0, dir, &calls) } else { - arg = old + arg = prog.CloneArg(old) calls = g.MutateArg(arg) } if g.Target().ArgContainsAny(arg) { @@ -144,7 +144,7 @@ func (arch *arch) generateUsbHidDeviceDescriptor(g *prog.Gen, typ0 prog.Type, di if old == nil { arg = g.GenerateSpecialArg(typ0, dir, &calls) } else { - arg = old + arg = prog.CloneArg(old) calls = g.MutateArg(arg) } if g.Target().ArgContainsAny(arg) { |