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| author | Christophe JAILLET <christophe.jaillet@wanadoo.fr> | 2022-04-29 08:16:19 +0200 |
|---|---|---|
| committer | akpm <akpm@linux-foundation.org> | 2022-04-29 08:16:19 +0200 |
| commit | f47f758cff59c68015d6b9b9c077110df7c2c828 (patch) | |
| tree | 1060315d3e3d0299aec0807a805dd3c6174e54b7 /drivers/base/memory.c | |
| parent | mm: compaction: make sure highest is above the min_pfn (diff) | |
| download | linux-f47f758cff59c68015d6b9b9c077110df7c2c828.tar.xz linux-f47f758cff59c68015d6b9b9c077110df7c2c828.zip | |
drivers/base/memory: fix an unlikely reference counting issue in __add_memory_block()
__add_memory_block() calls both put_device() and device_unregister() when
storing the memory block into the xarray. This is incorrect because
xarray doesn't take an additional reference and device_unregister()
already calls put_device().
Triggering the issue looks really unlikely and its only effect should be
to log a spurious warning about a ref counted issue.
Link: https://lkml.kernel.org/r/d44c63d78affe844f020dc02ad6af29abc448fc4.1650611702.git.christophe.jaillet@wanadoo.fr
Fixes: 4fb6eabf1037 ("drivers/base/memory.c: cache memory blocks in xarray to accelerate lookup")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Scott Cheloha <cheloha@linux.vnet.ibm.com>
Cc: Nathan Lynch <nathanl@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'drivers/base/memory.c')
| -rw-r--r-- | drivers/base/memory.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 7222ff9b5e05..084d67fd55cc 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -636,10 +636,9 @@ static int __add_memory_block(struct memory_block *memory) } ret = xa_err(xa_store(&memory_blocks, memory->dev.id, memory, GFP_KERNEL)); - if (ret) { - put_device(&memory->dev); + if (ret) device_unregister(&memory->dev); - } + return ret; } |