fcntl: don't cap l_start and l_end values for F_GETLK64 in compat syscall

[sfrench/cifs-2.6.git] / fs / fcntl.c

diff --git a/fs/fcntl.c b/fs/fcntl.c
index 8d78ffd7b399d430f05fdb8b72b68dfa1bda3bcb..0522e283a4f48c1b5bfc2433de9ad12d82cfc891 100644 (file)
--- a/fs/fcntl.c
+++ b/fs/fcntl.c
@@ -563,6 +563,9 @@ static int put_compat_flock64(const struct flock *kfl, struct compat_flock64 __u
 {
        struct compat_flock64 fl;
 
+       BUILD_BUG_ON(sizeof(kfl->l_start) > sizeof(ufl->l_start));
+       BUILD_BUG_ON(sizeof(kfl->l_len) > sizeof(ufl->l_len));
+
        memset(&fl, 0, sizeof(struct compat_flock64));
        copy_flock_fields(&fl, kfl);
        if (copy_to_user(ufl, &fl, sizeof(struct compat_flock64)))
@@ -632,9 +635,8 @@ COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
                if (err)
                        break;
                err = fixup_compat_flock(&flock);
-               if (err)
-                       return err;
-               err = put_compat_flock(&flock, compat_ptr(arg));
+               if (!err)
+                       err = put_compat_flock(&flock, compat_ptr(arg));
                break;
        case F_GETLK64:
        case F_OFD_GETLK:
@@ -642,12 +644,8 @@ COMPAT_SYSCALL_DEFINE3(fcntl64, unsigned int, fd, unsigned int, cmd,
                if (err)
                        break;
                err = fcntl_getlk(f.file, convert_fcntl_cmd(cmd), &flock);
-               if (err)
-                       break;
-               err = fixup_compat_flock(&flock);
-               if (err)
-                       return err;
-               err = put_compat_flock64(&flock, compat_ptr(arg));
+               if (!err)
+                       err = put_compat_flock64(&flock, compat_ptr(arg));
                break;
        case F_SETLK:
        case F_SETLKW:
@@ -725,7 +723,7 @@ static void send_sigio_to_task(struct task_struct *p,
         * F_SETSIG can change ->signum lockless in parallel, make
         * sure we read it once and use the same value throughout.
         */
-       int signum = ACCESS_ONCE(fown->signum);
+       int signum = READ_ONCE(fown->signum);
 
        if (!sigio_perm(p, fown, signum))
                return;