From: Antonio Ospite <[email protected]> ===================================================================== | This is a commit scheduled for the next v2.6.34 longterm release. | | If you see a problem with using this for longterm, please comment.| =====================================================================
commit d20d5ffab92f00188f360c44c791a5ffb988247c upstream. BUG: unable to handle kernel NULL pointer dereference at 0000000000000028 IP: [<ffffffffa02c66b4>] hidraw_ioctl+0xfc/0x32c [hid] [...] This is reproducible by disconnecting the device while userspace does ioctl in a loop and doesn't check return values in order to exit the loop. [PG: slightly/trivially reworked for backport to 34] Signed-off-by: Antonio Ospite <[email protected]> Signed-off-by: Jiri Kosina <[email protected]> Signed-off-by: Paul Gortmaker <[email protected]> --- drivers/hid/hidraw.c | 6 ++++++ 1 files changed, 6 insertions(+), 0 deletions(-) diff --git a/drivers/hid/hidraw.c b/drivers/hid/hidraw.c index 6eadf1a..0db1a0f 100644 --- a/drivers/hid/hidraw.c +++ b/drivers/hid/hidraw.c @@ -243,6 +243,11 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd, void __user *user_arg = (void __user*) arg; lock_kernel(); + if (!dev) { + ret = -ENODEV; + goto out; + } + switch (cmd) { case HIDIOCGRDESCSIZE: if (put_user(dev->hid->rsize, (int __user *)arg)) @@ -315,6 +320,7 @@ static long hidraw_ioctl(struct file *file, unsigned int cmd, ret = -ENOTTY; } +out: unlock_kernel(); return ret; } -- 1.7.4.4 _______________________________________________ stable mailing list [email protected] http://linux.kernel.org/mailman/listinfo/stable
