Messages in this thread Patch in this message | | | From | Huai-Yuan Liu <> | Subject | [PATCH V2] ppdev: Add an error check in register_device | Date | Sun, 7 Apr 2024 16:03:58 +0800 |
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In register_device, the return value of ida_simple_get is unchecked, in witch ida_simple_get will use an invalid index value.
To address this issue, index should be checked after ida_simple_get. When the index value is abnormal, a warning message should be printed, the port should be dropped, and the value should be recorded, then jump to 'err'.
Fixes: 9a69645dde11 ("ppdev: fix registering same device name") Signed-off-by: Huai-Yuan Liu <qq810974084@gmail.com> --- V2: * In patch V2, we found that parport_find_number implicitly calls parport_get_port(). So when dealing with abnormal index values, we should call parport_put_port() to throw away the reference to the port. --- drivers/char/ppdev.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/drivers/char/ppdev.c b/drivers/char/ppdev.c index 4c188e9e477c..ac5a93d39fbd 100644 --- a/drivers/char/ppdev.c +++ b/drivers/char/ppdev.c @@ -300,6 +300,13 @@ static int register_device(int minor, struct pp_struct *pp) } index = ida_simple_get(&ida_index, 0, 0, GFP_KERNEL); + if (index < 0) { + pr_warn("%s: failed to get index!\n", name); + parport_put_port(port); + rc = index; + goto err; + } + memset(&ppdev_cb, 0, sizeof(ppdev_cb)); ppdev_cb.irq_func = pp_irq; ppdev_cb.flags = (pp->flags & PP_EXCL) ? PARPORT_FLAG_EXCL : 0; -- 2.34.1
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