forked from Minki/linux
7cf4be68b1
Check for memset()/memzero_explicit() followed by kfree()/vfree()/kvfree(). Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
102 lines
2.0 KiB
Plaintext
102 lines
2.0 KiB
Plaintext
// SPDX-License-Identifier: GPL-2.0-only
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///
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/// Use kzfree, kvfree_sensitive rather than memset or
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/// memzero_explicit followed by kfree
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///
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// Confidence: High
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// Copyright: (C) 2020 Denis Efremov ISPRAS
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// Options: --no-includes --include-headers
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//
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// Keywords: kzfree, kvfree_sensitive
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//
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virtual context
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virtual patch
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virtual org
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virtual report
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@initialize:python@
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@@
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# kmalloc_oob_in_memset uses memset to explicitly trigger out-of-bounds access
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filter = frozenset(['kmalloc_oob_in_memset', 'kzfree', 'kvfree_sensitive'])
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def relevant(p):
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return not (filter & {el.current_element for el in p})
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@cond@
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position ok;
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@@
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if (...)
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\(memset@ok\|memzero_explicit@ok\)(...);
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@r depends on !patch forall@
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expression E;
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position p : script:python() { relevant(p) };
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position m != cond.ok;
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type T;
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@@
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(
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* memset@m((T)E, 0, ...);
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* memzero_explicit@m((T)E, ...);
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)
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... when != E
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when strict
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* \(kfree\|vfree\|kvfree\)(E)@p;
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@rp_memzero depends on patch@
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expression E, size;
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position p : script:python() { relevant(p) };
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position m != cond.ok;
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type T;
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@@
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- memzero_explicit@m((T)E, size);
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... when != E
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when strict
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// TODO: uncomment when kfree_sensitive will be merged.
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// Only this case is commented out because developers
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// may not like patches like this since kzfree uses memset
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// internally (not memzero_explicit).
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//(
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//- kfree(E)@p;
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//+ kfree_sensitive(E);
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//|
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- \(vfree\|kvfree\)(E)@p;
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+ kvfree_sensitive(E, size);
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//)
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@rp_memset depends on patch@
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expression E, size;
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position p : script:python() { relevant(p) };
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position m != cond.ok;
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type T;
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@@
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- memset@m((T)E, 0, size);
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... when != E
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when strict
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(
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- kfree(E)@p;
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+ kzfree(E);
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- \(vfree\|kvfree\)(E)@p;
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+ kvfree_sensitive(E, size);
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)
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@script:python depends on report@
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p << r.p;
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@@
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coccilib.report.print_report(p[0],
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"WARNING: opportunity for kzfree/kvfree_sensitive")
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@script:python depends on org@
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p << r.p;
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@@
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coccilib.org.print_todo(p[0],
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"WARNING: opportunity for kzfree/kvfree_sensitive")
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