diff options
| author | Anton Lindqvist <anton@basename.se> | 2019-05-14 03:14:26 +0200 |
|---|---|---|
| committer | Greg Steuck <blackgnezdo@gmail.com> | 2019-05-13 18:14:26 -0700 |
| commit | ada3c44cd19020225649eaf218f47cccf8007d45 (patch) | |
| tree | 4c9af12adcb78e0919833535f9760f952319d10e /sys/openbsd/init.go | |
| parent | 658d7563831e26dd4d83c238a86294ca3857a519 (diff) | |
sys/openbsd: prevent changing mutability flags on files (#1174)
This is especially problematic for file descriptors referring to tty/pty
devices since it can cause the SSH connection to the VM to die.
The ambition here is reduce the number of "lost connection/no output" failures
at the cost of limiting the coverage of chflags(2).
Diffstat (limited to 'sys/openbsd/init.go')
| -rw-r--r-- | sys/openbsd/init.go | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/sys/openbsd/init.go b/sys/openbsd/init.go index a5dcab448..bce74fbac 100644 --- a/sys/openbsd/init.go +++ b/sys/openbsd/init.go @@ -59,6 +59,24 @@ func isKcovFd(dev uint64) bool { func (arch *arch) SanitizeCall(c *prog.Call) { argStart := 1 switch c.Meta.CallName { + case "chflagsat": + argStart = 2 + fallthrough + case "chflags", "fchflags": + // Prevent changing mutability flags on files. This is + // especially problematic for file descriptors referring to + // tty/pty devices since it can cause the SSH connection to the + // VM to die. + flags := c.Args[argStart].(*prog.ConstArg) + badflags := [...]uint64{ + 0x00000002, // UF_IMMUTABLE + 0x00000004, // UF_APPEND + 0x00020000, // SF_IMMUTABLE + 0x00040000, // SF_APPEND + } + for _, f := range badflags { + flags.Val &= ^f + } case "mknodat": argStart = 2 fallthrough |