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usb: gadget: eliminate NULL pointer dereference (bugfix)
authorAndrzej Pietrasiewicz <andrzej.p@samsung.com>
Wed, 28 Mar 2012 07:30:50 +0000 (09:30 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 27 Apr 2012 16:51:08 +0000 (09:51 -0700)
commit2ac8fc00b350ba1aead453c9c1feb1d23a433321
tree7505fd1878f5cbfe47d4808185edccbcc80b1a6b
parent5eb68e665cadf165741a04c695a71cff11e1d4f1
usb: gadget: eliminate NULL pointer dereference (bugfix)

commit 92b0abf80c5c5f0e0d71d1309688a330fd74731b upstream.

usb: gadget: eliminate NULL pointer dereference (bugfix)

This patch fixes a bug which causes NULL pointer dereference in
ffs_ep0_ioctl. The bug happens when the FunctionFS is not bound (either
has not been bound yet or has been bound and then unbound) and can be
reproduced with running the following commands:

$ insmod g_ffs.ko
$ mount -t functionfs func /dev/usbgadget
$ ./null

where null.c is:

#include <fcntl.h>
#include <linux/usb/functionfs.h>

int main(void)
{
int fd = open("/dev/usbgadget/ep0", O_RDWR);
ioctl(fd, FUNCTIONFS_CLEAR_HALT);

return 0;
}

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/gadget/f_fs.c