42 lines
1.4 KiB
Diff
42 lines
1.4 KiB
Diff
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From af29a235531f66882e5a027e1348658b8d8c1e68 Mon Sep 17 00:00:00 2001
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From: Nicolas Iooss <nicolas.iooss@m4x.org>
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Date: Mon, 12 Jul 2021 10:44:28 +0200
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Subject: [PATCH] libsepol/cil: do not allow \0 in quoted strings
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Using the '\0' character in strings in a CIL policy is not expected to
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happen, and makes the flex tokenizer very slow. For example when
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generating a file with:
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python -c 'print("\"" + "\0"*100000 + "\"")' > policy.cil
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secilc fails after 26 seconds, on my desktop computer. Increasing the
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numbers of \0 makes this time increase significantly. But replacing \0
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with another character makes secilc fail in only few milliseconds.
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Fix this "possible denial of service" issue by forbidding \0 in strings
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in CIL policies.
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Fixes: https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=36016
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Signed-off-by: Nicolas Iooss <nicolas.iooss@m4x.org>
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---
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libsepol/cil/src/cil_lexer.l | 2 +-
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1 file changed, 1 insertion(+), 1 deletion(-)
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diff --git a/libsepol/cil/src/cil_lexer.l b/libsepol/cil/src/cil_lexer.l
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index e28c33ecb9f1..8bf2b6e7765a 100644
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--- a/libsepol/cil/src/cil_lexer.l
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+++ b/libsepol/cil/src/cil_lexer.l
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@@ -49,7 +49,7 @@ spec_char [\[\]\.\@\=\/\*\-\_\$\%\+\-\!\|\&\^\:\~\`\#\{\}\'\<\>\?\,]
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symbol ({digit}|{alpha}|{spec_char})+
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white [ \t]
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newline [\n\r]
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-qstring \"[^"\n]*\"
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+qstring \"[^"\n\0]*\"
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hll_lm ^;;\*
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comment ;
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--
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2.32.0
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