dialog: fix use-after-free and race in cluster replication - #3860
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bogdan-iancu merged 1 commit intoMay 26, 2026
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NormB
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April 1, 2026 11:33
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Any updates here? No progress has been made in the last 30 days, marking as stale. |
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Hi @NormB , could you please update your PR to the latest master ? |
Fix three bugs triggered when SIP-I messages with binary ISUP data are replicated across a dialog cluster with reinvite pinging enabled. 1. dlg_replicated_create: after _link_dlg_unsafe() links the dialog into the hash table, subsequent DLG_BIN_POP failures jumped to pre_linking_error which calls destroy_dlg() without unlinking. This leaves a dangling pointer in the hash chain — other workers dereference freed memory (GPF). Add post_linking_error label that calls unlink_unsafe_dlg() before destroy. 2. write_dialog_vars: the read lock on vals_lock was released between the sizing pass and the write pass. A concurrent store_dlg_value() (e.g. from persist_reinvite_pinging storing multipart SDP+ISUP bodies) can modify the vals list in between, causing a buffer overflow and corrupted serialization. Hold the read lock through both passes. 3. strip_esc: when len==1 and *c is backslash, *(c+1) reads one byte past the string. Add len>1 guard. Closes OpenSIPS#3858
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Thank you @NormB, let me work out the merge |
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Thank you @NormB |
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Summary
Fix three bugs triggered when SIP-I messages with binary ISUP data are replicated across a dialog cluster with reinvite pinging enabled.
dlg_replicated_create: after_link_dlg_unsafe()links the dialog into the hash table,DLG_BIN_POPfailures jumped topre_linking_errorwhich callsdestroy_dlg()without unlinking — leaves a dangling pointer in the hash chainwrite_dialog_vars: read lock released between the sizing pass and the write pass, allowing concurrentstore_dlg_value()to corrupt the bufferstrip_esc:*(c+1)read past string end when last byte is backslashReproduction
2-node cluster, 16 workers,
reinvite_ping_interval=5, 300 CPS with multipart SDP+ISUP bodies and concurrent re-INVITEs. Unpatched: SIGSEGV infree_dlg_dlg()—shm_free(0xabcdefedabcdefed)(freed-memory poison). Patched: same load, zero crashes.Closes #3858