[PATCH] compat_readv: Remove bogus area verify
The compat_do_readv_writev() function was doing a verify_area on the incoming iov, but the nr_segs value is not checked. If someone passes in a -1 for nr_segs, for instance, the function should return an EINVAL. However, it returns a EFAULT because the verify_area fails because it is checking an array of size MAX_UINT. The check is bogus, anyway, because the next check, compat_rw_copy_check_uvector(), will do all the necessary checking, anyway. The non-compat do_readv_writev() function doesn't do this check, so I think it's safe to just remove the code. Signed-off-by: Corey Minyard --- fs/read_write.c | 4 1 file changed, 4 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index 58e440d..1193ffd 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -901,10 +901,6 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, io_fn_t fn; iov_fn_t fnv; - ret = -EFAULT; - if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector))) - goto out; - ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, UIO_FASTIOV, iovstack, ); if (ret <= 0) -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
[PATCH] compat_readv: Remove bogus area verify
The compat_do_readv_writev() function was doing a verify_area on the incoming iov, but the nr_segs value is not checked. If someone passes in a -1 for nr_segs, for instance, the function should return an EINVAL. However, it returns a EFAULT because the verify_area fails because it is checking an array of size MAX_UINT. The check is bogus, anyway, because the next check, compat_rw_copy_check_uvector(), will do all the necessary checking, anyway. The non-compat do_readv_writev() function doesn't do this check, so I think it's safe to just remove the code. Signed-off-by: Corey Minyard cminy...@mvista.com --- fs/read_write.c | 4 1 file changed, 4 deletions(-) diff --git a/fs/read_write.c b/fs/read_write.c index 58e440d..1193ffd 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -901,10 +901,6 @@ static ssize_t compat_do_readv_writev(int type, struct file *file, io_fn_t fn; iov_fn_t fnv; - ret = -EFAULT; - if (!access_ok(VERIFY_READ, uvector, nr_segs*sizeof(*uvector))) - goto out; - ret = compat_rw_copy_check_uvector(type, uvector, nr_segs, UIO_FASTIOV, iovstack, iov); if (ret = 0) -- 1.8.3.1 -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
