kmemleak reports firmware loader funnies in iwlwifi

From: Dave Jones
Date: Fri Jun 26 2009 - 13:19:53 EST


After enabling kmemleak in the Fedora rawhide kernels, we've mostly
seen a flood of what appear to be false positives, but the below looks
really suspect..

https://bugzilla.redhat.com/show_bug.cgi?id=507971

Here's the summary...


iwlagn 0000:03:00.0: loaded firmware version 8.24.2.12
kmemleak: Freeing unknown object at 0xffffc90018070000
Pid: 1034, comm: NetworkManager Not tainted 2.6.31-0.25.rc0.git22.fc12.x86_64
#1
Call Trace:
[<ffffffff81139f74>] delete_object+0x5b/0x13b
[<ffffffff8113b012>] kmemleak_free+0x5b/0xb5
[<ffffffff8111dc51>] vfree+0x40/0x68
[<ffffffff813485e6>] release_firmware+0x49/0x6c
[<ffffffffa021997c>] ? iwl_mac_start+0xc5c/0x106b [iwlagn]
[<ffffffffa0219adc>] iwl_mac_start+0xdbc/0x106b [iwlagn]
[<ffffffff8109df9b>] ? __module_text_address+0x25/0x85


So it appears to be vfree'ing something that it had no knowledge of ever allocating.
afaict _request_firmware only vmallocs when it's using a firmware image built into
the driver, which isn't the case here, so I'm not sure why we end up trying
to vfree instead of kfree when we call release_firmware

anyone know what's going on here?

Dave
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/