compat fcntl errors

compat fcntl errors

[Olaf Hering]

This testcase fron ltp fails as 32bit binary on ppc64.
./testcases/network/nfs/cthon04/lock/tlock.c

fcntl(): Value too large for defined data type

Possible patch below.

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>

int main(int argc, char *argv[])
{
        int fd = open(argv[1], O_RDWR | O_CREAT, 0666);
        struct flock fl;
        off_t maxeof;

        memset(&fl, 0, sizeof(struct flock));
        // test 1.6 of cthon04 locking tests
        maxeof = (off_t)1 << (sizeof (off_t) * 8 - 2);
        maxeof += maxeof - 1;
        fl.l_type   = F_WRLCK;
        fl.l_whence = SEEK_SET;
        fl.l_start  = 1;
        fl.l_len    = maxeof;
        if (fcntl(fd, F_GETLK, &fl) < 0) {
                perror("fcntl()");
                exit(1);
        }
        printf("test 1.6 passes\n");

        close(fd);
        return 0;
}

 fs/compat.c |   30 ++++++++++++++++--------------
 fs/locks.c  |    3 ++-
 2 files changed, 18 insertions(+), 15 deletions(-)

Index: linux-2.6.13.cthon04/fs/compat.c
===================================================================
--- linux-2.6.13.cthon04.orig/fs/compat.c
+++ linux-2.6.13.cthon04/fs/compat.c
@@ -584,17 +584,18 @@ asmlinkage long compat_sys_fcntl64(unsig
 		ret = get_compat_flock(&f, compat_ptr(arg));
 		if (ret != 0)
 			break;
+		if ((cmd == F_GETLK) &&
+		    ((f.l_start > COMPAT_OFF_T_MAX) ||
+		     ((f.l_start + f.l_len - 1) > COMPAT_OFF_T_MAX))) {
+			ret = -EOVERFLOW;
+			break;
+		}
 		old_fs = get_fs();
 		set_fs(KERNEL_DS);
 		ret = sys_fcntl(fd, cmd, (unsigned long)&f);
 		set_fs(old_fs);
-		if (cmd == F_GETLK && ret == 0) {
-			if ((f.l_start >= COMPAT_OFF_T_MAX) ||
-			    ((f.l_start + f.l_len) > COMPAT_OFF_T_MAX))
-				ret = -EOVERFLOW;
-			if (ret == 0)
-				ret = put_compat_flock(&f, compat_ptr(arg));
-		}
+		if (cmd == F_GETLK && ret == 0)
+			ret = put_compat_flock(&f, compat_ptr(arg));
 		break;
 
 	case F_GETLK64:
@@ -603,19 +604,20 @@ asmlinkage long compat_sys_fcntl64(unsig
 		ret = get_compat_flock64(&f, compat_ptr(arg));
 		if (ret != 0)
 			break;
+		if ((cmd == F_GETLK64) &&
+		    ((f.l_start > COMPAT_LOFF_T_MAX) ||
+		     ((f.l_start + f.l_len - 1) > COMPAT_LOFF_T_MAX))) {
+			ret = -EOVERFLOW;
+			break;
+		}
 		old_fs = get_fs();
 		set_fs(KERNEL_DS);
 		ret = sys_fcntl(fd, (cmd == F_GETLK64) ? F_GETLK :
 				((cmd == F_SETLK64) ? F_SETLK : F_SETLKW),
 				(unsigned long)&f);
 		set_fs(old_fs);
-		if (cmd == F_GETLK64 && ret == 0) {
-			if ((f.l_start >= COMPAT_LOFF_T_MAX) ||
-			    ((f.l_start + f.l_len) > COMPAT_LOFF_T_MAX))
-				ret = -EOVERFLOW;
-			if (ret == 0)
-				ret = put_compat_flock64(&f, compat_ptr(arg));
-		}
+		if (cmd == F_GETLK64 && ret == 0)
+			ret = put_compat_flock64(&f, compat_ptr(arg));
 		break;
 
 	default:
Index: linux-2.6.13.cthon04/fs/locks.c
===================================================================
--- linux-2.6.13.cthon04.orig/fs/locks.c
+++ linux-2.6.13.cthon04/fs/locks.c
@@ -314,7 +314,8 @@ static int flock_to_posix_lock(struct fi
 
 	/* POSIX-1996 leaves the case l->l_len < 0 undefined;
 	   POSIX-2001 defines it. */
-	start += l->l_start;
+	if ((start += l->l_start) < 0)
+		return -EINVAL;
 	end = start + l->l_len - 1;
 	if (l->l_len < 0) {
 		end = start - 1;