From: Tobias Stoeckmann <tobias@stoeckmann.org>
To: linux-modules@vger.kernel.org
Subject: [PATCH] Verify memory sizes on 32 bit systems.
Date: Mon, 30 Jul 2018 21:01:46 +0200 [thread overview]
Message-ID: <20180730190146.GA8535@localhost> (raw)
Large file system support is activated by default, which means that
on 32 bit systems, off_t is 64 bit in size.
Using st.st_size or any other 64 bit variable with mmap can lead to
integer truncation and therefore insufficient memory mapping.
Signed-off-by: Tobias Stoeckmann <tobias@stoeckmann.org>
---
libkmod/libkmod-file.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/libkmod/libkmod-file.c b/libkmod/libkmod-file.c
index 5eeba6a..86f34c6 100644
--- a/libkmod/libkmod-file.c
+++ b/libkmod/libkmod-file.c
@@ -255,6 +255,8 @@ static int load_reg(struct kmod_file *file)
return -errno;
file->size = st.st_size;
+ if ((uintmax_t)st.st_size > (uintmax_t)SIZE_MAX)
+ return -EFBIG;
file->memory = mmap(NULL, file->size, PROT_READ, MAP_PRIVATE,
file->fd, 0);
if (file->memory == MAP_FAILED)
--
2.13.2
next reply other threads:[~2018-07-30 20:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-30 19:01 Tobias Stoeckmann [this message]
2018-08-03 21:07 ` [PATCH] Verify memory sizes on 32 bit systems Lucas De Marchi
2018-08-03 21:10 ` Tobias Stoeckmann
2018-08-03 21:33 ` Lucas De Marchi
2018-08-03 21:51 ` Tobias Stoeckmann
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