diff --git a/arch/alpha/kernel/ptrace.c b/arch/alpha/kernel/ptrace.c index 940dfb406591..04abdec7f496 100644 --- a/arch/alpha/kernel/ptrace.c +++ b/arch/alpha/kernel/ptrace.c @@ -283,7 +283,7 @@ long arch_ptrace(struct task_struct *child, long request, /* When I and D space are separate, these will need to be fixed. */ case PTRACE_PEEKTEXT: /* read word at location addr. */ case PTRACE_PEEKDATA: - copied = access_process_vm(child, addr, &tmp, sizeof(tmp), + copied = ptrace_access_vm(child, addr, &tmp, sizeof(tmp), FOLL_FORCE); ret = -EIO; if (copied != sizeof(tmp)) diff --git a/arch/blackfin/kernel/ptrace.c b/arch/blackfin/kernel/ptrace.c index 8d79286ee4e8..360d99645163 100644 --- a/arch/blackfin/kernel/ptrace.c +++ b/arch/blackfin/kernel/ptrace.c @@ -270,7 +270,7 @@ long arch_ptrace(struct task_struct *child, long request, switch (bfin_mem_access_type(addr, to_copy)) { case BFIN_MEM_ACCESS_CORE: case BFIN_MEM_ACCESS_CORE_ONLY: - copied = access_process_vm(child, addr, &tmp, + copied = ptrace_access_vm(child, addr, &tmp, to_copy, FOLL_FORCE); if (copied) break; @@ -323,7 +323,7 @@ long arch_ptrace(struct task_struct *child, long request, switch (bfin_mem_access_type(addr, to_copy)) { case BFIN_MEM_ACCESS_CORE: case BFIN_MEM_ACCESS_CORE_ONLY: - copied = access_process_vm(child, addr, &data, + copied = ptrace_access_vm(child, addr, &data, to_copy, FOLL_FORCE | FOLL_WRITE); break; diff --git a/arch/cris/arch-v32/kernel/ptrace.c b/arch/cris/arch-v32/kernel/ptrace.c index f0df654ac6fc..fe1f9cf7b391 100644 --- a/arch/cris/arch-v32/kernel/ptrace.c +++ b/arch/cris/arch-v32/kernel/ptrace.c @@ -147,7 +147,7 @@ long arch_ptrace(struct task_struct *child, long request, /* The trampoline page is globally mapped, no page table to traverse.*/ tmp = *(unsigned long*)addr; } else { - copied = access_process_vm(child, addr, &tmp, sizeof(tmp), FOLL_FORCE); + copied = ptrace_access_vm(child, addr, &tmp, sizeof(tmp), FOLL_FORCE); if (copied != sizeof(tmp)) break; diff --git a/arch/ia64/kernel/ptrace.c b/arch/ia64/kernel/ptrace.c index 31aa8c0f68e1..36f660da8124 100644 --- a/arch/ia64/kernel/ptrace.c +++ b/arch/ia64/kernel/ptrace.c @@ -1159,7 +1159,7 @@ arch_ptrace (struct task_struct *child, long request, case PTRACE_PEEKTEXT: case PTRACE_PEEKDATA: /* read word at location addr */ - if (access_process_vm(child, addr, &data, sizeof(data), + if (ptrace_access_vm(child, addr, &data, sizeof(data), FOLL_FORCE) != sizeof(data)) return -EIO; diff --git a/arch/mips/kernel/ptrace32.c b/arch/mips/kernel/ptrace32.c index 7e71a4e0281b..5fcbdcd7abd0 100644 --- a/arch/mips/kernel/ptrace32.c +++ b/arch/mips/kernel/ptrace32.c @@ -69,7 +69,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0) break; - copied = access_process_vm(child, (u64)addrOthers, &tmp, + copied = ptrace_access_vm(child, (u64)addrOthers, &tmp, sizeof(tmp), FOLL_FORCE); if (copied != sizeof(tmp)) break; @@ -178,7 +178,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0) break; ret = 0; - if (access_process_vm(child, (u64)addrOthers, &data, + if (ptrace_access_vm(child, (u64)addrOthers, &data, sizeof(data), FOLL_FORCE | FOLL_WRITE) == sizeof(data)) break; diff --git a/arch/powerpc/kernel/ptrace32.c b/arch/powerpc/kernel/ptrace32.c index 010b7b310237..1e887f3a61a6 100644 --- a/arch/powerpc/kernel/ptrace32.c +++ b/arch/powerpc/kernel/ptrace32.c @@ -73,7 +73,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, if (get_user(addrOthers, (u32 __user * __user *)addr) != 0) break; - copied = access_process_vm(child, (u64)addrOthers, &tmp, + copied = ptrace_access_vm(child, (u64)addrOthers, &tmp, sizeof(tmp), FOLL_FORCE); if (copied != sizeof(tmp)) break; @@ -178,7 +178,7 @@ long compat_arch_ptrace(struct task_struct *child, compat_long_t request, if (get_user(addrOthers, (u32 __user * __user *)addr) != 0) break; ret = 0; - if (access_process_vm(child, (u64)addrOthers, &tmp, + if (ptrace_access_vm(child, (u64)addrOthers, &tmp, sizeof(tmp), FOLL_FORCE | FOLL_WRITE) == sizeof(tmp)) break; diff --git a/include/linux/mm.h b/include/linux/mm.h index a92c8d73aeaf..0b5b2e4df14e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -1270,6 +1270,8 @@ extern int access_process_vm(struct task_struct *tsk, unsigned long addr, void * unsigned int gup_flags); extern int access_remote_vm(struct mm_struct *mm, unsigned long addr, void *buf, int len, unsigned int gup_flags); +extern int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, + unsigned long addr, void *buf, int len, unsigned int gup_flags); long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, diff --git a/include/linux/ptrace.h b/include/linux/ptrace.h index e13bfdf7f314..e0e539321ab9 100644 --- a/include/linux/ptrace.h +++ b/include/linux/ptrace.h @@ -8,6 +8,9 @@ #include /* For task_active_pid_ns. */ #include +extern int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, + void *buf, int len, unsigned int gup_flags); + /* * Ptrace flags * diff --git a/kernel/ptrace.c b/kernel/ptrace.c index e82c15cadd6d..49ba7c1ade9d 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -27,6 +27,35 @@ #include #include +/* + * Access another process' address space via ptrace. + * Source/target buffer must be kernel space, + * Do not walk the page table directly, use get_user_pages + */ +int ptrace_access_vm(struct task_struct *tsk, unsigned long addr, + void *buf, int len, unsigned int gup_flags) +{ + struct mm_struct *mm; + int ret; + + mm = get_task_mm(tsk); + if (!mm) + return 0; + + if (!tsk->ptrace || + (current != tsk->parent) || + ((get_dumpable(mm) != SUID_DUMP_USER) && + !ptracer_capable(tsk, mm->user_ns))) { + mmput(mm); + return 0; + } + + ret = __access_remote_vm(tsk, mm, addr, buf, len, gup_flags); + mmput(mm); + + return ret; +} + /* * ptrace a task: make the debugger its new parent and @@ -535,7 +564,8 @@ int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst int this_len, retval; this_len = (len > sizeof(buf)) ? sizeof(buf) : len; - retval = access_process_vm(tsk, src, buf, this_len, FOLL_FORCE); + retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE); + if (!retval) { if (copied) break; @@ -562,7 +592,7 @@ int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long ds this_len = (len > sizeof(buf)) ? sizeof(buf) : len; if (copy_from_user(buf, src, this_len)) return -EFAULT; - retval = access_process_vm(tsk, dst, buf, this_len, + retval = ptrace_access_vm(tsk, dst, buf, this_len, FOLL_FORCE | FOLL_WRITE); if (!retval) { if (copied) @@ -1126,7 +1156,7 @@ int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr, unsigned long tmp; int copied; - copied = access_process_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); + copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE); if (copied != sizeof(tmp)) return -EIO; return put_user(tmp, (unsigned long __user *)data); @@ -1137,7 +1167,7 @@ int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, { int copied; - copied = access_process_vm(tsk, addr, &data, sizeof(data), + copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), FOLL_FORCE | FOLL_WRITE); return (copied == sizeof(data)) ? 0 : -EIO; } @@ -1155,7 +1185,7 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, switch (request) { case PTRACE_PEEKTEXT: case PTRACE_PEEKDATA: - ret = access_process_vm(child, addr, &word, sizeof(word), + ret = ptrace_access_vm(child, addr, &word, sizeof(word), FOLL_FORCE); if (ret != sizeof(word)) ret = -EIO; @@ -1165,7 +1195,7 @@ int compat_ptrace_request(struct task_struct *child, compat_long_t request, case PTRACE_POKETEXT: case PTRACE_POKEDATA: - ret = access_process_vm(child, addr, &data, sizeof(data), + ret = ptrace_access_vm(child, addr, &data, sizeof(data), FOLL_FORCE | FOLL_WRITE); ret = (ret != sizeof(data) ? -EIO : 0); break; diff --git a/mm/memory.c b/mm/memory.c index e18c57bdc75c..cbb1e5e5f791 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -3868,7 +3868,7 @@ EXPORT_SYMBOL_GPL(generic_access_phys); * Access another process' address space as given in mm. If non-NULL, use the * given task for page fault accounting. */ -static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, +int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, unsigned long addr, void *buf, int len, unsigned int gup_flags) { struct vm_area_struct *vma; diff --git a/mm/nommu.c b/mm/nommu.c index 8b8faaf2a9e9..44265e00b701 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1808,7 +1808,7 @@ void filemap_map_pages(struct fault_env *fe, } EXPORT_SYMBOL(filemap_map_pages); -static int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, +int __access_remote_vm(struct task_struct *tsk, struct mm_struct *mm, unsigned long addr, void *buf, int len, unsigned int gup_flags) { struct vm_area_struct *vma;