diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/ptrace.c | 42 |
1 files changed, 36 insertions, 6 deletions
diff --git a/kernel/ptrace.c b/kernel/ptrace.c index b48bb2fef8c9..630bd8abaab1 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -27,6 +27,35 @@ #include <linux/cn_proc.h> #include <linux/compat.h> +/* + * 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, int write) +{ + 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, write); + mmput(mm); + + return ret; +} + static int ptrace_trapping_sleep_fn(void *flags) { @@ -558,7 +587,8 @@ 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, 0); + retval = ptrace_access_vm(tsk, src, buf, this_len, 0); + if (!retval) { if (copied) break; @@ -585,7 +615,7 @@ 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, 1); + retval = ptrace_access_vm(tsk, dst, buf, this_len, 1); if (!retval) { if (copied) break; @@ -1130,7 +1160,7 @@ 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), 0); + copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), 0); if (copied != sizeof(tmp)) return -EIO; return put_user(tmp, (unsigned long __user *)data); @@ -1141,7 +1171,7 @@ int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr, { int copied; - copied = access_process_vm(tsk, addr, &data, sizeof(data), 1); + copied = ptrace_access_vm(tsk, addr, &data, sizeof(data), 1); return (copied == sizeof(data)) ? 0 : -EIO; } @@ -1159,7 +1189,7 @@ 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), 0); + ret = ptrace_access_vm(child, addr, &word, sizeof(word), 0); if (ret != sizeof(word)) ret = -EIO; else @@ -1168,7 +1198,7 @@ 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), 1); + ret = ptrace_access_vm(child, addr, &data, sizeof(data), 1); ret = (ret != sizeof(data) ? -EIO : 0); break; |