From 8811930dc74a503415b35c4a79d14fb0b408a361 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Fri, 8 Feb 2008 08:49:14 -0800 Subject: [PATCH] splice: missing user pointer access verification vmsplice_to_user() must always check the user pointer and length with access_ok() before copying. Likewise, for the slow path of copy_from_user_mmap_sem() we need to check that we may read from the user region. Signed-off-by: Jens Axboe Cc: Wojciech Purczynski Signed-off-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds --- fs/splice.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/splice.c b/fs/splice.c index 4ee49e86edde..14e2262c0a04 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1179,6 +1179,9 @@ static int copy_from_user_mmap_sem(void *dst, const void __user *src, size_t n) { int partial; + if (!access_ok(VERIFY_READ, src, n)) + return -EFAULT; + pagefault_disable(); partial = __copy_from_user_inatomic(dst, src, n); pagefault_enable(); @@ -1387,6 +1390,11 @@ static long vmsplice_to_user(struct file *file, const struct iovec __user *iov, break; } + if (unlikely(!access_ok(VERIFY_WRITE, base, len))) { + error = -EFAULT; + break; + } + sd.len = 0; sd.total_len = len; sd.flags = flags; -- 2.20.1