Commit Graph

76 Commits

Author SHA1 Message Date
Anna Zaks b508d29b78 [analyzer] Don't crash even when the system functions are redefined.
(Applied changes to CStringAPI, Malloc, and Taint.)

This might almost never happen, but we should not crash even if it does.
This fixes a crash on the internal analyzer buildbot, where postgresql's
configure was redefining memmove (radar://11219852).

llvm-svn: 154451
2012-04-10 23:41:11 +00:00
Anna Zaks 3705a1ee10 [analyzer] Change naming in bug reports "tainted" -> "untrusted"
llvm-svn: 151120
2012-02-22 02:35:58 +00:00
Dylan Noblesmith e27789991d Basic: import OwningPtr<> into clang namespace
llvm-svn: 149798
2012-02-05 02:12:40 +00:00
Ted Kremenek 49b1e38e4b Change references to 'const ProgramState *' to typedef 'ProgramStateRef'.
At this point this is largely cosmetic, but it opens the door to replace
ProgramStateRef with a smart pointer that more eagerly acts in the role
of reclaiming unused ProgramState objects.

llvm-svn: 149081
2012-01-26 21:29:00 +00:00
Anna Zaks bf740512ec [analyzer] Add more C taint sources/sinks.
llvm-svn: 148844
2012-01-24 19:32:25 +00:00
Anna Zaks 97bef5642e [analyzer] It's possible to have a non PointerType expression evaluate to a Loc value. When this happens, use the default type.
llvm-svn: 148631
2012-01-21 06:59:01 +00:00
David Blaikie e4d798f078 More dead code removal (using -Wunreachable-code)
llvm-svn: 148577
2012-01-20 21:50:17 +00:00
Anna Zaks 3b754b25bd [analyzer] Add socket API as a source of taint.
llvm-svn: 148518
2012-01-20 00:11:19 +00:00
Anna Zaks 7f6a6b7507 [analyzer] Refactor: prePropagateTaint ->
TaintPropagationRule::process().

Also remove the "should be a pointer argument" warning - should be
handled elsewhere.

llvm-svn: 148372
2012-01-18 02:45:13 +00:00
Anna Zaks 560dbe9ac9 [analyzer] Taint: warn when tainted data is used to specify a buffer
size (Ex: in malloc, memcpy, strncpy..)

(Maybe some of this could migrate to the CString checker. One issue
with that is that we might want to separate security issues from
regular API misuse.)

llvm-svn: 148371
2012-01-18 02:45:11 +00:00
Anna Zaks 5d324e509c [analyzer] Taint: add taint propagation rules for string and memory copy
functions.

llvm-svn: 148370
2012-01-18 02:45:07 +00:00
Anna Zaks 3666d2c160 [analyzer] Taint: generalize taint propagation to simplify adding more
taint propagation functions.

llvm-svn: 148266
2012-01-17 00:37:02 +00:00
Anna Zaks 0244cd7450 [analyzer] Taint: add system and popen as undesirable sinks for taint
data.

llvm-svn: 148176
2012-01-14 02:48:40 +00:00
Anna Zaks a31f6b9559 [analyzer] Taint: when looking up a binding, provide the type.
llvm-svn: 148080
2012-01-13 00:56:51 +00:00
Anna Zaks b3fa8d7dd1 [analyzer] Add taint transfer by strcpy & others (part 1).
To simplify the process:
Refactor taint generation checker to simplify passing the
information on which arguments need to be tainted from pre to post
visit.

Todo: We need to factor out the code that sema is using to identify the
string and memcpy functions and use it here and in the CString checker.

llvm-svn: 148010
2012-01-12 02:22:34 +00:00
Rafael Espindola 47dbcd1d39 Remove unused variable.
llvm-svn: 147744
2012-01-07 22:52:07 +00:00
Anna Zaks 126a2ef920 [analyzer] Add basic format string vulnerability checking.
We already have a more conservative check in the compiler (if the
format string is not a literal, we warn). Still adding it here for
completeness and since this check is stronger - only triggered if the
format string is tainted.

llvm-svn: 147714
2012-01-07 02:33:10 +00:00
Ted Kremenek 632e3b7ee2 [analyzer] Make the entries in 'Environment' context-sensitive by making entries map from
(Stmt*,LocationContext*) pairs to SVals instead of Stmt* to SVals.

This is needed to support basic IPA via inlining.  Without this, we cannot tell
if a Stmt* binding is part of the current analysis scope (StackFrameContext) or
part of a parent context.

This change introduces an uglification of the use of getSVal(), and thus takes
two steps forward and one step back.  There are also potential performance implications
of enlarging the Environment.  Both can be addressed going forward by refactoring the
APIs and optimizing the internal representation of Environment.  This patch
mainly introduces the functionality upon when we want to build upon (and clean up).

llvm-svn: 147688
2012-01-06 22:09:28 +00:00
Anna Zaks 3b0ab206d2 [analyzer] Add support for taint flowing through a function (atoi).
Check if the input parameters are tainted (or point to tainted data) on
a checkPreStmt<CallExpr>. If the output should be tainted, record it in
the state. On post visit (checkPostStmt<CallExpr>), use the state to
make decisions (in addition to the existing logic). Use this logic for
atoi and fscanf.

llvm-svn: 146793
2011-12-17 00:26:34 +00:00
Anna Zaks e48ee50324 [analyzer] Better stdin support.
llvm-svn: 146748
2011-12-16 18:28:50 +00:00
Anna Zaks 099fe3fb28 [analyzer] Treat stdin as a source of taint.
Some of the test cases do not currently work because the analyzer core
does not seem to call checkers for pre/post DeclRefExpr visits.
(Opened radar://10573500. To be fixed later on.)

llvm-svn: 146536
2011-12-14 00:56:18 +00:00
Anna Zaks eefc0e9342 [analyzer] Mark output of fscanf and fopen as tainted.
llvm-svn: 146533
2011-12-14 00:56:02 +00:00
Anna Zaks d6bb3227de [analyzer] Mark getenv output as tainted.
Also, allow adding taint to a region (not only a symbolic value).

llvm-svn: 146532
2011-12-14 00:55:58 +00:00
Anna Zaks 7c96b7db96 [analyzer] CStringChecker should not rely on the analyzer generating UndefOrUnknown value when it cannot reason about the expression.
We are now often generating expressions even if the solver is not known to be able to simplify it. This is another cleanup of the existing code, where the rest of the analyzer and checkers should not base their logic on knowing ahead of the time what the solver can reason about. 

In this case, CStringChecker is performing a check for overflow of 'left+right' operation. The overflow can be checked with either 'maxVal-left' or 'maxVal-right'. Previously, the decision was based on whether the expresion evaluated to undef or not. With this patch, we check if one of the arguments is a constant, in which case we know that 'maxVal-const' is easily simplified. (Another option is to use canReasonAbout() method of the solver here, however, it's currently is protected.)

This patch also contains 2 small bug fixes:
 - swap the order of operators inside SValBuilder::makeGenericVal.
 - handle a case when AddeVal is unknown in GenericTaintChecker::getPointedToSymbol.

llvm-svn: 146343
2011-12-11 18:43:40 +00:00
Anna Zaks 457c68726c [analyzer] Warn when non pointer arguments are passed to scanf (only when running taint checker).
There is an open radar to implement better scanf checking as a Sema warning. However, a bit of redundancy is fine in this case.

llvm-svn: 144964
2011-11-18 02:26:36 +00:00
Anna Zaks 5c5bf9b634 [analyzer] Adding generic taint checker.
The checker is responsible for defining attack surface and adding taint to symbols.

llvm-svn: 144825
2011-11-16 19:58:13 +00:00