From 23d5e74935e1cba21811e511f7a7ed2bd59205c5 Mon Sep 17 00:00:00 2001 From: vangyzen Date: Wed, 28 Nov 2018 16:20:04 +0000 Subject: [PATCH] MFS r341146 MFC r340994 Prevent kernel stack disclosure in getcontext/swapcontext Expand r338982 to cover freebsd32 interfaces on amd64, mips, and powerpc. Approved by: re (gjb) Security: FreeBSD-EN-18:12.mem Security: CVE-2018-17155 Sponsored by: Dell EMC Isilon --- sys/amd64/ia32/ia32_signal.c | 2 ++ sys/mips/mips/freebsd32_machdep.c | 2 ++ sys/powerpc/powerpc/exec_machdep.c | 2 ++ 3 files changed, 6 insertions(+) diff --git a/sys/amd64/ia32/ia32_signal.c b/sys/amd64/ia32/ia32_signal.c index ffc4693be18..9d7139551fb 100644 --- a/sys/amd64/ia32/ia32_signal.c +++ b/sys/amd64/ia32/ia32_signal.c @@ -261,6 +261,7 @@ freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap) if (uap->ucp == NULL) ret = EINVAL; else { + bzero(&uc, sizeof(uc)); ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); PROC_LOCK(td->td_proc); uc.uc_sigmask = td->td_sigmask; @@ -301,6 +302,7 @@ freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap) if (uap->oucp == NULL || uap->ucp == NULL) ret = EINVAL; else { + bzero(&uc, sizeof(uc)); ia32_get_mcontext(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); PROC_LOCK(td->td_proc); uc.uc_sigmask = td->td_sigmask; diff --git a/sys/mips/mips/freebsd32_machdep.c b/sys/mips/mips/freebsd32_machdep.c index 73c5848029f..0c32cb65fbe 100644 --- a/sys/mips/mips/freebsd32_machdep.c +++ b/sys/mips/mips/freebsd32_machdep.c @@ -294,6 +294,7 @@ freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap) if (uap->ucp == NULL) ret = EINVAL; else { + bzero(&uc, sizeof(uc)); get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); PROC_LOCK(td->td_proc); uc.uc_sigmask = td->td_sigmask; @@ -333,6 +334,7 @@ freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap) if (uap->oucp == NULL || uap->ucp == NULL) ret = EINVAL; else { + bzero(&uc, sizeof(uc)); get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); PROC_LOCK(td->td_proc); uc.uc_sigmask = td->td_sigmask; diff --git a/sys/powerpc/powerpc/exec_machdep.c b/sys/powerpc/powerpc/exec_machdep.c index 18ff66f26f3..044c8cc8670 100644 --- a/sys/powerpc/powerpc/exec_machdep.c +++ b/sys/powerpc/powerpc/exec_machdep.c @@ -783,6 +783,7 @@ freebsd32_getcontext(struct thread *td, struct freebsd32_getcontext_args *uap) if (uap->ucp == NULL) ret = EINVAL; else { + bzero(&uc, sizeof(uc)); get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); PROC_LOCK(td->td_proc); uc.uc_sigmask = td->td_sigmask; @@ -822,6 +823,7 @@ freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap) if (uap->oucp == NULL || uap->ucp == NULL) ret = EINVAL; else { + bzero(&uc, sizeof(uc)); get_mcontext32(td, &uc.uc_mcontext, GET_MC_CLEAR_RET); PROC_LOCK(td->td_proc); uc.uc_sigmask = td->td_sigmask; -- 2.45.0