diff options
| author | Marcel Holtmann <marcel@holtmann.org> | 2007-03-07 13:22:40 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2007-03-09 10:50:32 -0800 |
| commit | 7670279989a552a7a8afd275368d55a4f3b5054b (patch) | |
| tree | deae130ab7a80eb75c7608ebae324a2211e81220 /drivers | |
| parent | 248059edc6503eac8baac39dad42e76383824720 (diff) | |
Fix buffer overflow in Omnikey CardMan 4040 driver (CVE-2007-0005)
Based on a patch from Don Howard <dhoward@redhat.com>
When calling write() with a buffer larger than 512 bytes, the
driver's write buffer overflows, allowing to overwrite the EIP and
execute arbitrary code with kernel privileges.
In read(), there exists a similar problem, but coming from the device.
A malicous or buggy device sending more than 512 bytes can overflow
of the driver's read buffer, with the same effects as above.
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Harald Welte <laforge@gnumonks.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/char/pcmcia/cm4040_cs.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/char/pcmcia/cm4040_cs.c b/drivers/char/pcmcia/cm4040_cs.c index 9b1ff7e8f89..3a6d05bfc1c 100644 --- a/drivers/char/pcmcia/cm4040_cs.c +++ b/drivers/char/pcmcia/cm4040_cs.c @@ -273,6 +273,7 @@ static ssize_t cm4040_read(struct file *filp, char __user *buf, DEBUGP(6, dev, "BytesToRead=%lu\n", bytes_to_read); min_bytes_to_read = min(count, bytes_to_read + 5); + min_bytes_to_read = min_t(size_t, min_bytes_to_read, READ_WRITE_BUFFER_SIZE); DEBUGP(6, dev, "Min=%lu\n", min_bytes_to_read); @@ -340,7 +341,7 @@ static ssize_t cm4040_write(struct file *filp, const char __user *buf, return 0; } - if (count < 5) { + if ((count < 5) || (count > READ_WRITE_BUFFER_SIZE)) { DEBUGP(2, dev, "<- cm4040_write buffersize=%Zd < 5\n", count); return -EIO; } |