diff options
| author | Dmitry Vyukov <dvyukov@google.com> | 2018-02-23 11:55:37 +0100 |
|---|---|---|
| committer | Dmitry Vyukov <dvyukov@google.com> | 2018-02-23 11:55:37 +0100 |
| commit | 3be86de046e00897e05f1330b9fe17459735f294 (patch) | |
| tree | 1fa55f296bb212d1c8ed68e972035fb56374dfe5 /sys/linux/init.go | |
| parent | 334641584880cd238fc32dc6f436e7e10efdf3de (diff) | |
sys/linux: prevent programs from doing arbitrary writes with ARCH_SET_FS
Diffstat (limited to 'sys/linux/init.go')
| -rw-r--r-- | sys/linux/init.go | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/sys/linux/init.go b/sys/linux/init.go index aee900fcc..d127efbfb 100644 --- a/sys/linux/init.go +++ b/sys/linux/init.go @@ -32,6 +32,8 @@ func initTarget(target *prog.Target) { FITHAW: target.ConstMap["FITHAW"], PTRACE_TRACEME: target.ConstMap["PTRACE_TRACEME"], CLOCK_REALTIME: target.ConstMap["CLOCK_REALTIME"], + ARCH_SET_FS: target.ConstMap["ARCH_SET_FS"], + ARCH_SET_GS: target.ConstMap["ARCH_SET_GS"], } target.MakeMmap = arch.makeMmap @@ -100,6 +102,8 @@ type arch struct { FITHAW uint64 PTRACE_TRACEME uint64 CLOCK_REALTIME uint64 + ARCH_SET_FS uint64 + ARCH_SET_GS uint64 } // createMmapCall creates a "normal" mmap call that maps [addr, addr+size) memory range. @@ -183,6 +187,14 @@ func (arch *arch) sanitizeCall(c *prog.Call) { if code.Val%128 == 67 || code.Val%128 == 68 { code.Val = 1 } + case "arch_prctl": + // fs holds address of tls, if a program messes it at least signal + // handling will break. This also allows a program to do writes + // at arbitrary addresses, which usually leads to machine outbreak. + cmd := c.Args[0].(*prog.ConstArg) + if uint64(uint32(cmd.Val)) == arch.ARCH_SET_FS { + cmd.Val = arch.ARCH_SET_GS + } } switch c.Meta.Name { |