From d4a4683ca054ed9917dfc9e3ff0f7ecf74ad90d6 Mon Sep 17 00:00:00 2001 From: Greg KH Date: Mon, 15 Feb 2010 09:37:46 -0800 Subject: USB: usbfs: only copy the actual data received We need to only copy the data received by the device to userspace, not the whole kernel buffer, which can contain "stale" data. Thanks to Marcus Meissner for pointing this out and testing the fix. Reported-by: Marcus Meissner Tested-by: Marcus Meissner Cc: Alan Stern Cc: Linus Torvalds Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devio.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/usb/core/devio.c') diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 6e8bcdfd23b4..ca948bbc388f 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1312,9 +1312,9 @@ static int processcompl(struct async *as, void __user * __user *arg) void __user *addr = as->userurb; unsigned int i; - if (as->userbuffer) + if (as->userbuffer && urb->actual_length) if (copy_to_user(as->userbuffer, urb->transfer_buffer, - urb->transfer_buffer_length)) + urb->actual_length)) goto err_out; if (put_user(as->status, &userurb->status)) goto err_out; @@ -1475,9 +1475,9 @@ static int processcompl_compat(struct async *as, void __user * __user *arg) void __user *addr = as->userurb; unsigned int i; - if (as->userbuffer) + if (as->userbuffer && urb->actual_length) if (copy_to_user(as->userbuffer, urb->transfer_buffer, - urb->transfer_buffer_length)) + urb->actual_length)) return -EFAULT; if (put_user(as->status, &userurb->status)) return -EFAULT; -- cgit v1.2.3 From ddeee0b2eec2a51b0712b04de4b39e7bec892a53 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Tue, 16 Feb 2010 12:35:07 -0800 Subject: USB: usbfs: properly clean up the as structure on error paths I notice that the processcompl_compat() function seems to be leaking the 'struct async *as' in the error paths. I think that the calling convention is fundamentally buggered. The caller is the one that did the "reap_as()" to get the as thing, the caller should be the one to free it too. Freeing it in the caller also means that it very clearly always gets freed, and avoids the need for any "free in the error case too". From: Linus Torvalds Cc: Alan Stern Cc: Marcus Meissner Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devio.c | 40 ++++++++++++++++++++++++++-------------- 1 file changed, 26 insertions(+), 14 deletions(-) (limited to 'drivers/usb/core/devio.c') diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index ca948bbc388f..a678186f218f 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1334,14 +1334,11 @@ static int processcompl(struct async *as, void __user * __user *arg) } } - free_async(as); - if (put_user(addr, (void __user * __user *)arg)) return -EFAULT; return 0; err_out: - free_async(as); return -EFAULT; } @@ -1371,8 +1368,11 @@ static struct async *reap_as(struct dev_state *ps) static int proc_reapurb(struct dev_state *ps, void __user *arg) { struct async *as = reap_as(ps); - if (as) - return processcompl(as, (void __user * __user *)arg); + if (as) { + int retval = processcompl(as, (void __user * __user *)arg); + free_async(as); + return retval; + } if (signal_pending(current)) return -EINTR; return -EIO; @@ -1380,11 +1380,16 @@ static int proc_reapurb(struct dev_state *ps, void __user *arg) static int proc_reapurbnonblock(struct dev_state *ps, void __user *arg) { + int retval; struct async *as; - if (!(as = async_getcompleted(ps))) - return -EAGAIN; - return processcompl(as, (void __user * __user *)arg); + as = async_getcompleted(ps); + retval = -EAGAIN; + if (as) { + retval = processcompl(as, (void __user * __user *)arg); + free_async(as); + } + return retval; } #ifdef CONFIG_COMPAT @@ -1497,7 +1502,6 @@ static int processcompl_compat(struct async *as, void __user * __user *arg) } } - free_async(as); if (put_user(ptr_to_compat(addr), (u32 __user *)arg)) return -EFAULT; return 0; @@ -1506,8 +1510,11 @@ static int processcompl_compat(struct async *as, void __user * __user *arg) static int proc_reapurb_compat(struct dev_state *ps, void __user *arg) { struct async *as = reap_as(ps); - if (as) - return processcompl_compat(as, (void __user * __user *)arg); + if (as) { + int retval = processcompl_compat(as, (void __user * __user *)arg); + free_async(as); + return retval; + } if (signal_pending(current)) return -EINTR; return -EIO; @@ -1515,11 +1522,16 @@ static int proc_reapurb_compat(struct dev_state *ps, void __user *arg) static int proc_reapurbnonblock_compat(struct dev_state *ps, void __user *arg) { + int retval; struct async *as; - if (!(as = async_getcompleted(ps))) - return -EAGAIN; - return processcompl_compat(as, (void __user * __user *)arg); + retval = -EAGAIN; + as = async_getcompleted(ps); + if (as) { + retval = processcompl_compat(as, (void __user * __user *)arg); + free_async(as); + } + return retval; } -- cgit v1.2.3