Messages in this thread Patch in this message |  | | Subject | [PATCH] Fix buffer overflow in Omnikey CardMan 4040 driver | | From | Marcel Holtmann <> | | Date | Tue, 06 Mar 2007 22:12:00 +0100 |
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Hi Linus,
the attached patch fixes a buffer overflow in the Omnikey CardMan 4040 driver that could lead to a potential arbitrary code execution with kernel privileges.
Regards
Marcel
[PATCH] 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>
--- commit 5be3f29dbb70cf7b3eaa5e1be6dfa553c98ea1ad tree 158eb27c16e372650d7bc8c6536b46f052932148 parent c3442e296517aee733d62fc3fe03211598902c7d author Marcel Holtmann <marcel@holtmann.org> Tue, 06 Mar 2007 22:02:23 +0100 committer Marcel Holtmann <marcel@holtmann.org> Tue, 06 Mar 2007 22:02:23 +0100
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 0e82968..f2e4ec4 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; } |  |