python3/SOURCES/00482-cve-2026-6100.patch
2026-04-28 01:36:31 -04:00

51 lines
1.9 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Stan Ulbrych <stan@python.org>
Date: Mon, 13 Apr 2026 22:42:24 +0100
Subject: 00482: CVE-2026-6100
Fix a possible UAF in {LZMA,BZ2,_Zlib}Decompressor
Backported from Python 3.10
---
.../Security/2026-04-10-16-28-21.gh-issue-148395.kfzm0G.rst | 5 +++++
Modules/_bz2module.c | 1 +
Modules/_lzmamodule.c | 1 +
3 files changed, 7 insertions(+)
create mode 100644 Misc/NEWS.d/next/Security/2026-04-10-16-28-21.gh-issue-148395.kfzm0G.rst
diff --git a/Misc/NEWS.d/next/Security/2026-04-10-16-28-21.gh-issue-148395.kfzm0G.rst b/Misc/NEWS.d/next/Security/2026-04-10-16-28-21.gh-issue-148395.kfzm0G.rst
new file mode 100644
index 0000000000..b095329bd9
--- /dev/null
+++ b/Misc/NEWS.d/next/Security/2026-04-10-16-28-21.gh-issue-148395.kfzm0G.rst
@@ -0,0 +1,5 @@
+Fix a dangling input pointer in :class:`lzma.LZMADecompressor`,
+:class:`bz2.BZ2Decompressor`
+when memory allocation fails with :exc:`MemoryError`, which could let a
+subsequent :meth:`!decompress` call read or write through a stale pointer to
+the already-released caller buffer.
diff --git a/Modules/_bz2module.c b/Modules/_bz2module.c
index fe06953ec4..394ed22540 100644
--- a/Modules/_bz2module.c
+++ b/Modules/_bz2module.c
@@ -587,6 +587,7 @@ decompress(BZ2Decompressor *d, char *data, size_t len, Py_ssize_t max_length)
return result;
error:
+ bzs->next_in = NULL;
Py_XDECREF(result);
return NULL;
}
diff --git a/Modules/_lzmamodule.c b/Modules/_lzmamodule.c
index 3d3645af92..0157dce83a 100644
--- a/Modules/_lzmamodule.c
+++ b/Modules/_lzmamodule.c
@@ -1053,6 +1053,7 @@ decompress(Decompressor *d, uint8_t *data, size_t len, Py_ssize_t max_length)
return result;
error:
+ lzs->next_in = NULL;
Py_XDECREF(result);
return NULL;
}