Messages in this thread | | | Date | Fri, 4 Nov 2022 16:40:52 -0400 | Subject | Re: Coverity: kfd_parse_subtype_cache(): Memory - corruptions | From | Felix Kuehling <> |
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On 2022-11-04 15:41, coverity-bot wrote: > Hello! > > This is an experimental semi-automated report about issues detected by > Coverity from a scan of next-20221104 as part of the linux-next scan project: > https://scan.coverity.com/projects/linux-next-weekly-scan > > You're getting this email because you were associated with the identified > lines of code (noted below) that were touched by commits: > > Fri Dec 8 23:08:59 2017 -0500 > 3a87177eb141 ("drm/amdkfd: Add topology support for dGPUs") > > Coverity reported the following: > > *** CID 1527133: Memory - corruptions (OVERRUN) > drivers/gpu/drm/amd/amdkfd/kfd_crat.c:1113 in kfd_parse_subtype_cache() > 1107 props->cache_size = cache->cache_size; > 1108 props->cacheline_size = cache->cache_line_size; > 1109 props->cachelines_per_tag = cache->lines_per_tag; > 1110 props->cache_assoc = cache->associativity; > 1111 props->cache_latency = cache->cache_latency; > 1112 > vvv CID 1527133: Memory - corruptions (OVERRUN) > vvv Overrunning array "cache->sibling_map" of 32 bytes by passing it to a function which accesses it at byte offset 63 using argument "64UL". [Note: The source code implementation of the function has been overridden by a builtin model.] > 1113 memcpy(props->sibling_map, cache->sibling_map, > 1114 sizeof(props->sibling_map)); > 1115 > 1116 /* set the sibling_map_size as 32 for CRAT from ACPI */ > 1117 props->sibling_map_size = CRAT_SIBLINGMAP_SIZE; > 1118 > > If this is a false positive, please let us know so we can mark it as > such, or teach the Coverity rules to be smarter. If not, please make > sure fixes get into linux-next. :) For patches fixing this, please > include these lines (but double-check the "Fixes" first): > > Reported-by: coverity-bot <keescook+coverity-bot@chromium.org> > Addresses-Coverity-ID: 1527133 ("Memory - corruptions") > Fixes: 3a87177eb141 ("drm/amdkfd: Add topology support for dGPUs") > > I'm not sure why this suddenly appeared after 5 years, but the read > over-run looks legit:
I think this was introduced by a more recent patch that was in fact meant to fix an array overrun on HW that is outgrowing the CRAT sibling map size:
> commit 0938fbeb6f53fc44bc9b19784dee28496e68ba0c > Author: Ma Jun <Jun.Ma2@amd.com> > Date: Wed Nov 2 15:53:26 2022 +0800 > > drm/amdkfd: Fix the warning of array-index-out-of-bounds > > For some GPUs with more CUs, the original sibling_map[32] > in struct crat_subtype_cache is not enough > to save the cache information when create the VCRAT table, > so skip filling the struct crat_subtype_cache info instead > fill struct kfd_cache_properties directly to fix this problem. > > Signed-off-by: Ma Jun <Jun.Ma2@amd.com> > Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com> > Signed-off-by: Alex Deucher <alexander.deucher@amd.com> I added Ma Jun to the email.
Regards, Felix
> > struct crat_subtype_cache { > ... > uint8_t sibling_map[CRAT_SIBLINGMAP_SIZE]; > > #define CRAT_SIBLINGMAP_SIZE 32 > > > struct kfd_cache_properties { > ... > uint8_t sibling_map[CACHE_SIBLINGMAP_SIZE]; > > #define CACHE_SIBLINGMAP_SIZE 64 > > Thanks for your attention! >
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