Date: Thu, 16 May 2019 11:59:02 +0000 From: bugzilla-noreply@freebsd.org To: bugs@FreeBSD.org Subject: [Bug 237922] Kernel stack disclosure in function freebsd32_swapcontext of sys/arm64/arm64/freebsd32_machdep.c Message-ID: <bug-237922-227@https.bugs.freebsd.org/bugzilla/>
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https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=237922 Bug ID: 237922 Summary: Kernel stack disclosure in function freebsd32_swapcontext of sys/arm64/arm64/freebsd32_machdep.c Product: Base System Version: CURRENT Hardware: Any OS: Any Status: New Severity: Affects Many People Priority: --- Component: kern Assignee: bugs@FreeBSD.org Reporter: yangx92@hotmail.com There is a kernel stack disclosure vulnerability in function freebsd32_swapcontext of sys/arm64/arm64/freebsd32_machdep.c. int freebsd32_swapcontext(struct thread *td, struct freebsd32_swapcontext_args *uap) { ucontext32_t uc; int ret; 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; PROC_UNLOCK(td->td_proc); ret = copyout(&uc, uap->oucp, UC32_COPY_SIZE); if (ret == 0) { ret = copyin(uap->ucp, &uc, UC32_COPY_SIZE); if (ret == 0) { ret = set_mcontext32(td, &uc.uc_mcontext); kern_sigprocmask(td, SIG_SETMASK, &uc.uc_sigmask, NULL, 0); } } } return (ret); } There is no initialization in else branch, which can lead to leaking stack information to user space. This is the vulnerability that are same with CVE-2018-17155 which was fixed in https://github.com/freebsd/freebsd/commit/ca2c73670f229fe64818fd64c8cdd5b517912966. -- You are receiving this mail because: You are the assignee for the bug.help
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