elf: Initialize libc_map to NULL on namespace creation
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Description |
dj/TryBot-apply_patch |
success
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Patch applied to master at the time it was sent
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dj/TryBot-32bit |
success
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Build for i686
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Commit Message
It seems that a stale libc_map value will be used (and not
overwritten) by a dlmopen after a dlclose that has deallocated
the namespace. This may not be visible easily because the libc
link map can be allocated at the same address.
Fixes commit ec935dea6332cb22f9881cd1162bad156173f4b0 ("elf:
Implement __libc_early_init").
---
elf/dl-open.c | 4 ++++
1 file changed, 4 insertions(+)
base-commit: 6f85dbf102ad7982409ba0fe96886caeb6389fef
Comments
* Florian Weimer via Libc-alpha:
> It seems that a stale libc_map value will be used (and not
> overwritten) by a dlmopen after a dlclose that has deallocated
> the namespace. This may not be visible easily because the libc
> link map can be allocated at the same address.
>
> Fixes commit ec935dea6332cb22f9881cd1162bad156173f4b0 ("elf:
> Implement __libc_early_init").
The new version is here:
[PATCH] elf: Call __libc_early_init for reused namespaces (bug 29528)
<https://sourceware.org/pipermail/libc-alpha/2022-August/141696.html>
Thanks,
Florian
@@ -850,6 +850,10 @@ no more namespaces available for dlmopen()"));
++GL(dl_nns);
}
+ /* Clear any potential dangling libc link map references. */
+ GL(dl_ns)[nsid].libc_map = NULL;
+ GL(dl_ns)[nsid].libc_map_early_init = NULL;
+
_dl_debug_update (nsid)->r_state = RT_CONSISTENT;
}
/* Never allow loading a DSO in a namespace which is empty. Such