On 08/16/2015 12:24 PM, Doug Ledford wrote: > On 08/16/2015 04:19 AM, Matan Barak wrote: >> >> >> On 8/15/2015 5:14 PM, Doug Ledford wrote: >>> On 08/06/2015 01:14 PM, Matan Barak wrote: >>>> Separate the cleanup and release IB cache functions. >>>> The cleanup function delete all GIDs and unregister the event channel, >>>> while the release function frees all memory. The cleanup function is >>>> called after all clients were removed (in the device un-registration >>>> process). >>>> >>>> The release function is called after the device was put. >>>> This is in order to avoid use-after-free errors if ther vendor >>>> driver's teardown code uses IB cache. >>>> >>>> Squash-into: 'IB/core: Add RoCE GID table management' >>>> Signed-off-by: Matan Barak <[email protected]> >>> >>> I had originally used the v1 of this patch instead of v2. In order to >>> make sure I didn't miss anything, I hand compared the final results of >>> the v1 patch to what this patch would have created if I had used it. I >>> found a few things worth nothing, comments inline below. >>> >>>> @@ -903,20 +924,28 @@ int ib_cache_setup_one(struct ib_device *device) >>>> (rdma_end_port(device) - >>>> rdma_start_port(device) + 1), >>>> GFP_KERNEL); >>>> - err = gid_table_setup_one(device); >>>> - >>>> - if (!device->cache.pkey_cache || !device->cache.gid_cache || >>>> + if (!device->cache.pkey_cache || >>>> !device->cache.lmc_cache) { >>>> printk(KERN_WARNING "Couldn't allocate cache " >>>> "for %s\n", device->name); >>>> - err = -ENOMEM; >>>> - goto err; >>>> + /* pkey_cache is freed here because we later access it's >>>> + * elements. >>>> + */ >>>> + kfree(device->cache.pkey_cache); >>>> + device->cache.pkey_cache = NULL; >>>> + return -ENOMEM; >>> >>> This function is unnecessarily convoluted IMO. A simple change to using >>> kzalloc() for the pkey_cache alloc eliminates part of the issue. As a >>> result, I fixed this function up to be different than either patch. >>> Please look over my results and make sure you agree with my changes. >>> >>>> } >>>> >>>> - for (p = 0; p <= rdma_end_port(device) - >>>> rdma_start_port(device); ++p) { >>>> + for (p = 0; p <= rdma_end_port(device) - >>>> rdma_start_port(device); ++p) >>>> device->cache.pkey_cache[p] = NULL; >>> >>> For instance this goes away entirely by using kzalloc(). >>> >>> The rest looked ok. I have to fixup the ordering changes between sysfs >>> and cache to make the v1 patch match the v2 patch. >>> >>> >> >> Thanks for the squashing and re-ordering these patches. >> I think you're missing if (device->cache.pkey_cache) over the for pkey >> free loop in ib_cache_release_one. > > I think you're right, but I think that particular issue exists in both > versions of the code (mine and yours). In particular, a failure during > ib_register_device should result in a call to ib_dealloc_device which > will result in a call to ib_cache_release_one, which will happen whether > ib_cache_setup_one returns an error or not. So, ib_cache_release_one > must check pkey_cache before releasing the ports because it can't assume > the original setup succeeded. > >> Otherwise, the allocation of >> device->cache.pkey_cache might has failed and you dereference an invalid >> address device->cache.pkey_cache[p]. >> >> In addition, ib_device_release calls ib_cache_release_one with device >> instead of dev (which has the wrong type). >> ib_register_device calls ib_cache_clean_one that I can't really find :) > > Both of these turned up in compile tests. I've since resolved them. > Hand merge issues ;-) >
I've pushed what I think is a fixed version to github. Please feel free to review. -- Doug Ledford <[email protected]> GPG KeyID: 0E572FDD
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