procfs: fix pthread cross-thread naming if !PR_DUMPABLE

[cascardo/linux.git] / fs / exec.c

diff --git a/fs/exec.c b/fs/exec.c
index c4010b8..e92419f 100644 (file)
--- a/fs/exec.c
+++ b/fs/exec.c
@@ -850,15 +850,25 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
        if (ret)
                return ret;
 
+       ret = deny_write_access(file);
+       if (ret)
+               return ret;
+
        i_size = i_size_read(file_inode(file));
-       if (max_size > 0 && i_size > max_size)
-               return -EFBIG;
-       if (i_size <= 0)
-               return -EINVAL;
+       if (max_size > 0 && i_size > max_size) {
+               ret = -EFBIG;
+               goto out;
+       }
+       if (i_size <= 0) {
+               ret = -EINVAL;
+               goto out;
+       }
 
        *buf = vmalloc(i_size);
-       if (!*buf)
-               return -ENOMEM;
+       if (!*buf) {
+               ret = -ENOMEM;
+               goto out;
+       }
 
        pos = 0;
        while (pos < i_size) {
@@ -876,18 +886,21 @@ int kernel_read_file(struct file *file, void **buf, loff_t *size,
 
        if (pos != i_size) {
                ret = -EIO;
-               goto out;
+               goto out_free;
        }
 
        ret = security_kernel_post_read_file(file, *buf, i_size, id);
        if (!ret)
                *size = pos;
 
-out:
+out_free:
        if (ret < 0) {
                vfree(*buf);
                *buf = NULL;
        }
+
+out:
+       allow_write_access(file);
        return ret;
 }
 EXPORT_SYMBOL_GPL(kernel_read_file);
@@ -1387,7 +1400,12 @@ static void bprm_fill_uid(struct linux_binprm *bprm)
        kuid_t uid;
        kgid_t gid;
 
-       /* clear any previous set[ug]id data from a previous binary */
+       /*
+        * Since this can be called multiple times (via prepare_binprm),
+        * we must clear any previous work done when setting set[ug]id
+        * bits from any earlier bprm->file uses (for example when run
+        * first for a setuid script then again for its interpreter).
+        */
        bprm->cred->euid = current_euid();
        bprm->cred->egid = current_egid();