bugfix: fix heap-use-after-free in receiveuntil after read error - #2520
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waterWang wants to merge 1 commit into
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bugfix: fix heap-use-after-free in receiveuntil after read error#2520waterWang wants to merge 1 commit into
waterWang wants to merge 1 commit into
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ngx_http_lua_socket_tcp_finalize_read_part clears cp->upstream but leaves u->input_filter_ctx pointing at the compiled pattern. After a read error the iterator userdata becomes garbage-collected; its __gc handler sees cp->upstream == NULL and does not clear u->input_filter_ctx, leaving a dangling pointer. A later sock:close() dereferences it in ngx_http_lua_socket_tcp_finalize, causing a heap-use-after-free. Clear u->input_filter_ctx on both sides of the relationship when finalizing the read part, matching what tcp_finalize already does.
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@waterWang We need to add test cases to reproduce this issue althrough it seem harmness. |
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Closes #1146.
ngx_http_lua_socket_tcp_finalize_read_partclearscp->upstreambut leaves
u->input_filter_ctxpointing at the compiled pattern.After a read error the iterator userdata is garbage-collected; its
__gchandler seescp->upstream == NULLand does not clearu->input_filter_ctx, leaving a dangling pointer. A latersock:close()dereferences it inngx_http_lua_socket_tcp_finalize,causing a heap-use-after-free.
Clear
u->input_filter_ctxon both sides of the relationship whenfinalizing the read part, matching what
tcp_finalizealready does.Reported-by: BrookPanZM