Reset capacity_ in ShareData/ShareDiff to prevent stale shared memory reuse#7096
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Chessing234 wants to merge 1 commit intoBVLC:masterfrom
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Reset capacity_ in ShareData/ShareDiff to prevent stale shared memory reuse#7096Chessing234 wants to merge 1 commit intoBVLC:masterfrom
Chessing234 wants to merge 1 commit intoBVLC:masterfrom
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… reuse After ShareData(other), data_ points to other's memory but capacity_ retains the old blob's value. If Reshape() is later called with a size <= the stale capacity_, it skips allocation and silently reuses the shared pointer — corrupting other's data or causing use-after-free. Setting capacity_ to 0 forces Reshape() to allocate fresh memory, which is consistent with how capacity_ is initialized in constructors. Fixes BVLC#5439 Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
ShareData(other),data_points toother's memory butcapacity_retains the old blob's valueReshape()is later called with a size ≤ the stalecapacity_, it skips allocation (line 40:if (count_ > capacity_)) and silently reuses the shared pointer — corrupting the other blob's datacapacity_ = 0forcesReshape()to allocate fresh memory, consistent with how constructors initializecapacity_(lines 66, 73)ShareDifffor the identical issue withdiff_Fixes #5439
Changes
src/caffe/blob.cpp: Addcapacity_ = 0;after the pointer assignment in bothShareData()andShareDiff()Test plan
make runtest)Reshape()afterShareData()allocates new memory instead of reusing the shared pointer🤖 Generated with Claude Code