diff options
| author | Kees Cook <keescook@chromium.org> | 2018-03-28 00:06:14 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-08 15:26:31 +0300 |
| commit | 5f834dd24baec1f9926e8a06609e0906fd607b06 (patch) | |
| tree | e64f64f6251c420150d82cc6387ab68c6b6e6b24 | |
| parent | 66a65ca5b8fda6f5c55a9cf83e0fcb8e613baaa9 (diff) | |
| download | linux-5f834dd24baec1f9926e8a06609e0906fd607b06.tar.xz | |
/dev/mem: Avoid overwriting "err" in read_mem()
commit b5b38200ebe54879a7264cb6f33821f61c586a7e upstream.
Successes in probe_kernel_read() would mask failures in copy_to_user()
during read_mem().
Reported-by: Brad Spengler <spender@grsecurity.net>
Fixes: 22ec1a2aea73 ("/dev/mem: Add bounce buffer for copy-out")
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/char/mem.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 3a70dba2c645..f11224a5dc5c 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -137,7 +137,7 @@ static ssize_t read_mem(struct file *file, char __user *buf, while (count > 0) { unsigned long remaining; - int allowed; + int allowed, probe; sz = size_inside_page(p, count); @@ -160,9 +160,9 @@ static ssize_t read_mem(struct file *file, char __user *buf, if (!ptr) goto failed; - err = probe_kernel_read(bounce, ptr, sz); + probe = probe_kernel_read(bounce, ptr, sz); unxlate_dev_mem_ptr(p, ptr); - if (err) + if (probe) goto failed; remaining = copy_to_user(buf, bounce, sz); |